Re: [meteorite-list] Show me the Shock
It would have a cosmic-ray exposure age of 4.4 billion years. No iron meteorite has a CRE age anywhere near that. On Tue, Jul 25, 2023, 1:32 PM Alfredo Petrov via Meteorite-list < meteorite-list@meteoritecentral.com> wrote: > There could be pieces of iron from Earth's core floating around the solar > system, left over from the collision that created the Moon. Since we have > no direct chemical analyses of Earth core material, when an iron meteorite > falls, how would we know whether it was originally Earth material or not? > > On Tue, 25 Jul 2023 at 20:57, Robert Verish via Meteorite-list < > meteorite-list@meteoritecentral.com> wrote: > >> https://www.space.com/boomerang-meteorite-left-earth-and-returned >> >> A dark reddish-brown stone, picked up from the Sahara desert in Morocco a >> few years ago, appears to be an Earth rock that was flung into space >> where >> it stayed for thousands of years before returning home ? surprisingly >> intact. >> >> If scientists are right about this, the rock will officially be named the >> first meteorite to boomerang from Earth. [Not for certain!] >> >> The discovery team's work was *presented* >> ( >> https://conf.goldschmidt.info/goldschmidt/2023/meetingapp.cgi/Paper/20218 >> ) >> last week at an international geochemistry conference and has not yet been >> published in a peer-reviewed journal. >> >> "I think there is no doubt that this is a meteorite," said Frank Brenker, >> a >> geologist at the Goethe University Frankfurt in Germany, who was not >> involved with the new study. "It is just a matter of debate if it is >> really >> from Earth." [But, still could be the other way around.] >> >> Early diagnostic tests show the unusual stone features the same chemical >> composition as volcanic rocks on Earth. Interestingly, however, a few of >> its elements seem to have been altered into lighter forms of themselves. >> These lighter versions are known to occur only upon interacting with >> energetic *cosmic rays* ( https://www.space.com/32644-cosmic-rays.html ) >> in space, which provided one of two key pieces of evidence >> declaring the rock's trip beyond Earth, geologists say. >> >> Other pending measurements include unambiguous data about how much shock >> from the original impact the stone absorbed. This unique signature can be >> detected >> in the permanently altered microstructures of the mineral crystals >> forming the rock. >> Estimating the meteorite's shock levels is "something that can be checked >> or done >> in one hour or so max, using naked eyes," Ferrière said, "thus, not >> costly and a >> very important observation in this case." >> >> ( https://cdn.mos.cms.futurecdn.net/uh7CnCZNh4MNnFY78yR2ke.jpg ) >> __ >> Meteorite-list mailing list >> Meteorite-list@meteoritecentral.com >> https://pairlist2.pair.net/mailman/listinfo/meteorite-list >> > __ > Meteorite-list mailing list > Meteorite-list@meteoritecentral.com > https://pairlist2.pair.net/mailman/listinfo/meteorite-list > __ Meteorite-list mailing list Meteorite-list@meteoritecentral.com https://pairlist2.pair.net/mailman/listinfo/meteorite-list
Re: [meteorite-list] Show me the Shock
I am really surprised that a press release was issued on work that has not even been submitted for peer-reviewed publication. There seems to be no age data, no bulk chemical data, and no shock data. The authors seem to claim it was launched off Earth just 10,000 years ago, but I don't know where this comes from. Of course, there is no large terrestrial crater of that age. If the crystallization age is 4.5 billion years, then it is not from Earth. If the rock was launched from Earth, the required energy would melt it. The rock is listed as an achondrite, so that part fits, but it would have melted during launch 10,000 years ago (if that number is valid), not billions of years ago. I remain skeptical and surprised at the precipitous press release. On Tue, Jul 25, 2023, 11:58 AM Robert Verish via Meteorite-list < meteorite-list@meteoritecentral.com> wrote: > https://www.space.com/boomerang-meteorite-left-earth-and-returned > > A dark reddish-brown stone, picked up from the Sahara desert in Morocco a > few years ago, appears to be an Earth rock that was flung into space where > it stayed for thousands of years before returning home ? surprisingly > intact. > > If scientists are right about this, the rock will officially be named the > first meteorite to boomerang from Earth. [Not for certain!] > > The discovery team's work was *presented* > ( > https://conf.goldschmidt.info/goldschmidt/2023/meetingapp.cgi/Paper/20218 > ) > last week at an international geochemistry conference and has not yet been > published in a peer-reviewed journal. > > "I think there is no doubt that this is a meteorite," said Frank Brenker, a > geologist at the Goethe University Frankfurt in Germany, who was not > involved with the new study. "It is just a matter of debate if it is > really > from Earth." [But, still could be the other way around.] > > Early diagnostic tests show the unusual stone features the same chemical > composition as volcanic rocks on Earth. Interestingly, however, a few of > its elements seem to have been altered into lighter forms of themselves. > These lighter versions are known to occur only upon interacting with > energetic *cosmic rays* ( https://www.space.com/32644-cosmic-rays.html ) > in space, which provided one of two key pieces of evidence > declaring the rock's trip beyond Earth, geologists say. > > Other pending measurements include unambiguous data about how much shock > from the original impact the stone absorbed. This unique signature can be > detected > in the permanently altered microstructures of the mineral crystals forming > the rock. > Estimating the meteorite's shock levels is "something that can be checked > or done > in one hour or so max, using naked eyes," Ferrière said, "thus, not costly > and a > very important observation in this case." > > ( https://cdn.mos.cms.futurecdn.net/uh7CnCZNh4MNnFY78yR2ke.jpg ) > __ > Meteorite-list mailing list > Meteorite-list@meteoritecentral.com > https://pairlist2.pair.net/mailman/listinfo/meteorite-list > __ Meteorite-list mailing list Meteorite-list@meteoritecentral.com https://pairlist2.pair.net/mailman/listinfo/meteorite-list
Re: [meteorite-list] Terrestrial meteorite
I hadn't heard that a crystallization age has been determined, but if it turns out to be close to 4.5 Ga, then it is even less likely to be from Earth. On Thu, Jul 13, 2023 at 8:21 AM Carl Agee wrote: > > I classified something similar but not exactly the same recently. Also > plotting in the basaltic andesite field and near the TFL. > https://www.lpi.usra.edu/meteor/metbull.php?sea=NWA+15201=names=contains=50=ge==All=name=All=All0=Normal%20table=78425 > I definitely would not go out on a limb and say it is an Earth meteorite. It > is just one (remote?) possibility for the origin. There are several types of > meteorites that plot on or near the TFL, but that does not mean they are from > Earth. There is a growing number of ungrouped achondrites that indicate > significant basaltic to andesitic volcanism on early solar system bodies. A > crystallization age of NWA 13188 would be important to have to help prove it > is from Earth -- I haven't seen the 2023 Goldschmidt abstract (only the 2022 > MetSoc abstract). Has an age been determined yet? > Carl > * > Carl B. Agee > Director, Institute of Meteoritics > Professor, Earth and Planetary Sciences > University of New Mexico > > Shipping Address: > 11 Atole Way > Placitas, NM 87043 > > (505) 750-7172 > (505) 573-5131 > Email: cb.a...@gmail.com > > > > > > On Wed, Jul 12, 2023 at 5:57 PM ALAN RUBIN via Meteorite-list > wrote: >> >> [EXTERNAL] >> >> I discussed the possibility of terrestrial meteorites in Rubin (2015), >> Icarus 257, 221-229. Neglecting the effects of the Earth's atmosphere, >> it would take five times as much energy to launch a basaltic rock off >> the Earth as it would to launch the same mass rock off Mars. Except >> for Black Beauty, essentially every shergottite has been severely >> shocked during launch off Mars, transforming the crystalline >> plagioclase into maskelynite. (A few shergottites with no maskelynite >> were shocked-heated even more strongly.) A terrestrial basalt launched >> off Earth would be heavily shocked or completely impact melted. This >> does not seem to be the case for NWA 13188. I don't think it is >> terrestrial. >> >> On Wed, Jul 12, 2023 at 4:36 PM Mark Hammergren via Meteorite-list >> wrote: >> > >> > Thirty years ago, my thesis advisor, Don Brownlee, and I talked about >> > potential terrestrial meteorites and how their "asteroids" might be >> > identified among the population of near-Earth objects. Unfortunately for >> > me at the time, we decided that any strong identification would rely on >> > details of silicate chemistry that are tough to measure through >> > ground-based remote sensing. But we were certain that such bodies must >> > exist. >> > >> > On the same subject, the moon will be a great place to search for >> > terrestrial meteorites, and may prove to be the best place to investigate >> > the conditions of early Earth. Heck, we might even find fossils. >> > >> > On Wed, Jul 12, 2023, 12:27 PM Bob King via Meteorite-list >> > wrote: >> >> >> >> Mike, >> >> >> >> Go to >> >> https://www.researchgate.net/publication/361365963_Northwest_Africa_13188_A_meteorite_from_the_Earth >> >> At the top click on the blue bar that says download full text pdf. I just >> >> did it and no fee is required. >> >> >> >> Bob >> >> >> >> On Wed, Jul 12, 2023 at 9:12 AM Michael Farmer via Meteorite-list >> >> wrote: >> >>> >> >>> Unfortunately paywall >> >>> >> >>> >> >>> Sent from Yahoo Mail for iPhone >> >>> >> >>> On Wednesday, July 12, 2023, 2:05 AM, Albert Jambon via Meteorite-list >> >>> wrote: >> >>> >> >>> There was a presentation at the Goldschmidt Conference in Lyon this >> >>> week. Here is a link >> >>> >> >>> >> >>> >> >>> https://www.newscientist.com/article/2381928-meteorite-left-earth-then-landed-back-down-after-round-trip-to-space/ >> >>> >> >>> >> >>> >> >>> Albert JAMBON >> >>> >> >>> __ >> >>> Meteorite-list mailing list >> >>> Meteorite-list@meteoritecentral.com >> >>> https://pairlist2.pair.net/mailman/listinfo/meteorite-list >> >>>
Re: [meteorite-list] Terrestrial meteorite
I discussed the possibility of terrestrial meteorites in Rubin (2015), Icarus 257, 221-229. Neglecting the effects of the Earth's atmosphere, it would take five times as much energy to launch a basaltic rock off the Earth as it would to launch the same mass rock off Mars. Except for Black Beauty, essentially every shergottite has been severely shocked during launch off Mars, transforming the crystalline plagioclase into maskelynite. (A few shergottites with no maskelynite were shocked-heated even more strongly.) A terrestrial basalt launched off Earth would be heavily shocked or completely impact melted. This does not seem to be the case for NWA 13188. I don't think it is terrestrial. On Wed, Jul 12, 2023 at 4:36 PM Mark Hammergren via Meteorite-list wrote: > > Thirty years ago, my thesis advisor, Don Brownlee, and I talked about > potential terrestrial meteorites and how their "asteroids" might be > identified among the population of near-Earth objects. Unfortunately for me > at the time, we decided that any strong identification would rely on details > of silicate chemistry that are tough to measure through ground-based remote > sensing. But we were certain that such bodies must exist. > > On the same subject, the moon will be a great place to search for terrestrial > meteorites, and may prove to be the best place to investigate the conditions > of early Earth. Heck, we might even find fossils. > > On Wed, Jul 12, 2023, 12:27 PM Bob King via Meteorite-list > wrote: >> >> Mike, >> >> Go to >> https://www.researchgate.net/publication/361365963_Northwest_Africa_13188_A_meteorite_from_the_Earth >> At the top click on the blue bar that says download full text pdf. I just >> did it and no fee is required. >> >> Bob >> >> On Wed, Jul 12, 2023 at 9:12 AM Michael Farmer via Meteorite-list >> wrote: >>> >>> Unfortunately paywall >>> >>> >>> Sent from Yahoo Mail for iPhone >>> >>> On Wednesday, July 12, 2023, 2:05 AM, Albert Jambon via Meteorite-list >>> wrote: >>> >>> There was a presentation at the Goldschmidt Conference in Lyon this week. >>> Here is a link >>> >>> >>> >>> https://www.newscientist.com/article/2381928-meteorite-left-earth-then-landed-back-down-after-round-trip-to-space/ >>> >>> >>> >>> Albert JAMBON >>> >>> __ >>> Meteorite-list mailing list >>> Meteorite-list@meteoritecentral.com >>> https://pairlist2.pair.net/mailman/listinfo/meteorite-list >>> >>> __ >>> Meteorite-list mailing list >>> Meteorite-list@meteoritecentral.com >>> https://pairlist2.pair.net/mailman/listinfo/meteorite-list >> >> __ >> Meteorite-list mailing list >> Meteorite-list@meteoritecentral.com >> https://pairlist2.pair.net/mailman/listinfo/meteorite-list > > __ > Meteorite-list mailing list > Meteorite-list@meteoritecentral.com > https://pairlist2.pair.net/mailman/listinfo/meteorite-list -- Alan Rubin Institute of Geophysics and Planetary Physics Department of Earth, Planetary, and Space Sciences University of California 3845 Slichter Hall 603 Charles Young Dr. E Los Angeles, CA 90095-1567 USA office phone: 310-825-3202 fax: 310-206-3051 e-mail: aeru...@ucla.edu website: http://cosmochemists.igpp.ucla.edu/Rubin.html __ Meteorite-list mailing list Meteorite-list@meteoritecentral.com https://pairlist2.pair.net/mailman/listinfo/meteorite-list
Re: [meteorite-list] Regarding about the Glenn I. Huss Collection number H37.810
Of course, you could send an email to Gary Huss. On Wed, Feb 16, 2022, 7:59 AM Sean T. Murray via Meteorite-list < meteorite-list@meteoritecentral.com> wrote: > Mendy, > > Many times those gaps are specimens that were sold between editions. I > think they moved / sold some material quickly, and never bothered to > document it outside of the COA. They cataloged what they had, but there > were many gaps throughout both books. Nininger had the same issues with > his > "The Nininger Collection of Meteorites" book (1950). > > S. > > -Original Message- > From: Mendy Ouzillou via Meteorite-list > Sent: Wednesday, February 16, 2022 8:44 AM > To: 'Sanghyeok Lee' ; Meteorite-list@meteoritecentral.com > Subject: Re: [meteorite-list] Regarding about the Glenn I. Huss Collection > number H37.810 > > H37 is Canyon Diablo, however there is a gap in numbers between the first > (H37. 605 to H37.645) and second booklet (H37.860 to H37.1056) and your > number falls in that gap. > > Someone more knowledgeable can explain the gaps and if those numbers are > listed anywhere else. > > Mendy > > -Original Message- > From: Meteorite-list On > Behalf > Of Sanghyeok Lee via Meteorite-list > Sent: Wednesday, February 16, 2022 7:05 AM > To: Meteorite-list@meteoritecentral.com > Subject: [meteorite-list] Regarding about the Glenn I. Huss Collection > number H37.810 > > Dear list, > > I wonder if anyone are access to the Glenn I. Huss’s collection catalog > (especially second), I will be extremely appreciated when I know > information > related to the Huss number below… > > - H37.810 > > I suspect Canyon Diablo, and the entry likely available at the “The Second > Huss Collection of Meteorites (1986)” catalogue. If someone able to > provide > me a photograph or scanned version of this page or scanned catalogue, I > will > be literally thrilled of… > > Thank you for the all helps. > > Sincerely yours, > Sang-Hyeok, Lee > __ > > Meteorite-list mailing list > Meteorite-list@meteoritecentral.com > https://pairlist2.pair.net/mailman/listinfo/meteorite-list > > __ > > Meteorite-list mailing list > Meteorite-list@meteoritecentral.com > https://pairlist2.pair.net/mailman/listinfo/meteorite-list > > __ > > Meteorite-list mailing list > Meteorite-list@meteoritecentral.com > https://pairlist2.pair.net/mailman/listinfo/meteorite-list > __ Meteorite-list mailing list Meteorite-list@meteoritecentral.com https://pairlist2.pair.net/mailman/listinfo/meteorite-list
Re: [meteorite-list] Cristobalite
Free silica is at most an accessory component in known meteorites. If the whole rock has a high cristobalite peak, it is likely a terrestrial rock. Possibilities include sandstone, quartzite and various silicaceous igneous rocks. On Fri, May 21, 2021 at 4:05 PM yasmani.ceballo--- via Meteorite-list wrote: > > Hello friends > I have a surviving difractogram of a rock that was thinked to be > meteorite in the past, but now is lost. > The only information we have is the presence of these minerals: > cristobalite, quartz, olivine, enstatite, plagioclase and amorphous > materials. Probably super high peaks of cristobalite, followed by > quartz. > This is the only information we have, so I know is nothing, but with > that how we can say? > I mean, a high cristobalite peak mean anything? There is no > cristobalite in the geology of the area where the rock is believed to > have fallen. > Thanks > > > > > __ > > EXTREMELY RARE MARTIAN AND LUNAR MAIN MASS METEORITES > https://www.bonhams.com/auctions/27190/ > Coming to auction in Bonhams Meteorites Online sale. Browse 90+ lots of > superb planetary meteorite specimens & impact memorabilia, including rare > main mass Martian and Lunar meteorites. > > Bid online May 18-28 at Bonhams : Meteorites Online > https://www.bonhams.com/auctions/27190/ > __ > > Meteorite-list mailing list > Meteorite-list@meteoritecentral.com > https://pairlist2.pair.net/mailman/listinfo/meteorite-list -- Alan Rubin Institute of Geophysics and Planetary Physics Department of Earth, Planetary, and Space Sciences University of California 3845 Slichter Hall 603 Charles Young Dr. E Los Angeles, CA 90095-1567 USA office phone: 310-825-3202 fax: 310-206-3051 e-mail: aeru...@ucla.edu website: http://cosmochemists.igpp.ucla.edu/Rubin.html __ EXTREMELY RARE MARTIAN AND LUNAR MAIN MASS METEORITES https://www.bonhams.com/auctions/27190/ Coming to auction in Bonhams Meteorites Online sale. Browse 90+ lots of superb planetary meteorite specimens & impact memorabilia, including rare main mass Martian and Lunar meteorites. Bid online May 18-28 at Bonhams : Meteorites Online https://www.bonhams.com/auctions/27190/ __ Meteorite-list mailing list Meteorite-list@meteoritecentral.com https://pairlist2.pair.net/mailman/listinfo/meteorite-list
Re: [meteorite-list] Not an answer they like
I examine the specimens (or images of them if they do not send pieces) and then give them my best guess as to what the sample could be. Some people are insistent that I am wrong or that I am running some kind of a scam. I usually continue the conversation for one or two more rounds before I give up. At that point I sometimes tell them to try New England Meteoritical Services and let them know that they can examine the specimen for a small fee. If I find out that these folks have been sending the same sample to more than one researcher, I immediately stop corresponding with them because it is not fair to overworked researchers to be bedeviled by more than one meteorwrong provider. On Fri, Mar 19, 2021, 5:06 PM Ben Fisler via Meteorite-list < meteorite-list@meteoritecentral.com> wrote: > Tracy, >I usually offer to sell the individual “meteorites just like > theirs”, from hundreds of pounds, to a few tons, very cheaply, since I have > a near endless supply of the exact, same rocks, and that here in Phoenix, > they are commonly used in landscaping. That is usually the end of it. Try > it. > > Ben Fisler > > > On Mar 19, 2021, at 11:27 AM, Anne Black via Meteorite-list < > meteorite-list@meteoritecentral.com> wrote: > > > I like Randy's response best. And he certainly is the expert. > > Thank you Randy, I think I will keep your response and use it next time I > am asked, if you don't mind. > > Anne Black > IMPACTIKA.com > impact...@aol.com > > > -Original Message- > From: Korotev, Randy via Meteorite-list < > meteorite-list@meteoritecentral.com> > To: tracy latimer > Cc: meteorite-list@meteoritecentral.com < > meteorite-list@meteoritecentral.com> > Sent: Thu, Mar 18, 2021 3:23 pm > Subject: Re: [meteorite-list] Not an answer they like > > I send them this link. Doesn't usually help, though. > https://sites.wustl.edu/meteoritesite/items/thud/ > > > From: Meteorite-list on > behalf of tracy latimer via Meteorite-list < > meteorite-list@meteoritecentral.com> > Sent: Thursday, March 18, 2021 14:28 > To: meteorite-list@meteoritecentral.com > Subject: [meteorite-list] Not an answer they like > > I've been fielding a lot of e-mails this week from someone who is certain > that a meteorite nearly hit their house. The picture they sent me is of > what looks like a weathered lava bomb that likely washed free of an upslope > location and rolled/fell/bounced into his yard. They found it the > following day after a "loud thump that shook the house", then picked it up > and hosed it off, so don't have any pictures of it in situ, just a shallow > hole with muddy splash marks. I've told them several times that it doesn't > look like a meteorite: vesicles, not regmaglypts; no fusion crust, nothing > that identifies it as a likely meteorite, but they don't want to hear it. > Anyone who has dealt with a persistent "meteorite" finder, how did you > eventually get them to listen to reason/experience -- or not? > > Best! > Tracy Latimer > __ > > Visit our Facebook page https://www.facebook.com/meteoritecentral and the > Archives at http://www.meteorite-list-archives.com > __ > > Meteorite-list mailing list > Meteorite-list@meteoritecentral.com > https://pairlist3.pair.net/mailman/listinfo/meteorite-list > __ > > Visit our Facebook page https://www.facebook.com/meteoritecentral and the > Archives at http://www.meteorite-list-archives.com > __ > > Meteorite-list mailing list > Meteorite-list@meteoritecentral.com > https://pairlist3.pair.net/mailman/listinfo/meteorite-list > > __ > > Visit our Facebook page https://www.facebook.com/meteoritecentral and the > Archives at http://www.meteorite-list-archives.com > __ > > Meteorite-list mailing list > Meteorite-list@meteoritecentral.com > https://pairlist3.pair.net/mailman/listinfo/meteorite-list > __ Visit our Facebook page https://www.facebook.com/meteoritecentral and the Archives at http://www.meteorite-list-archives.com __ Meteorite-list mailing list Meteorite-list@meteoritecentral.com https://pairlist3.pair.net/mailman/listinfo/meteorite-list
Re: [meteorite-list] Modern Burnishing
For those who are interested, there is a similar pattern on the Haig IIIAB iron, as illustrated on page 62 of the book Meteorites and their Origins by G. J. McCall (1973). On Fri, Aug 14, 2020 at 12:30 PM Michael Farmer via Meteorite-list wrote: > > I hate it. Almost 100% made of glue is my guess. There’s no natural way to > make it look like a turf squeezed out of a tube. > > > Sent from Smallbiz Yahoo Mail for iPhone > > On Friday, August 14, 2020, 10:32 AM, Graham Ensor via Meteorite-list > wrote: > > I saw that too Paul. I think I saw it once before a while back, being > offered. I have never seen this shaping before either. Very unusual, but I > would guess it must be terrestrial weathering influenced by some sort of > internal structure...e.g. perhaps melt. I took the phrase "modern burnishing" > to be that it had been cleaned in some way to remove calichebut a vague > description. > > Graham > > On Fri, Aug 14, 2020 at 6:42 AM Paul Gessler via Meteorite-list > wrote: > > Want everyone's opinion / on this highly unusual morphology. > I don't doubt it is a real meteorite at all just that one side looks altered > or is HUGELY UNIQUE > Christies is currently selling it and gives a cryptic explanation for its > shape as "Modern burnishing" > What the hell does that mean exactly? > they also mention it could be naturally ventifacted.??? > > Either way I have never seen anything quite like it in the meteorite world. > > Anyone else have an explanation ... please chime in on this. > > https://onlineonly.christies.com/s/deep-impact-lunar-rare-meteorites/evoking-sculpture-ken-price-exotic-meteorite-morphology-nwa-13203-38/82821 > > Thanks > Paul Gessler > > __ > > Visit our Facebook page https://www.facebook.com/meteoritecentral and the > Archives at http://www.meteorite-list-archives.com > Meteorite-list mailing list > Meteorite-list@meteoritecentral.com > https://pairlist3.pair.net/mailman/listinfo/meteorite-list > > __ > > Visit our Facebook page https://www.facebook.com/meteoritecentral and the > Archives at http://www.meteorite-list-archives.com > Meteorite-list mailing list > Meteorite-list@meteoritecentral.com > https://pairlist3.pair.net/mailman/listinfo/meteorite-list > > __ > > Visit our Facebook page https://www.facebook.com/meteoritecentral and the > Archives at http://www.meteorite-list-archives.com > Meteorite-list mailing list > Meteorite-list@meteoritecentral.com > https://pairlist3.pair.net/mailman/listinfo/meteorite-list -- Alan Rubin Institute of Geophysics and Planetary Physics Department of Earth, Planetary, and Space Sciences University of California 3845 Slichter Hall 603 Charles Young Dr. E Los Angeles, CA 90095-1567 USA office phone: 310-825-3202 fax: 310-206-3051 e-mail: aeru...@ucla.edu website: http://cosmochemists.igpp.ucla.edu/Rubin.html __ Visit our Facebook page https://www.facebook.com/meteoritecentral and the Archives at http://www.meteorite-list-archives.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com https://pairlist3.pair.net/mailman/listinfo/meteorite-list
Re: [meteorite-list] Interesting take on Tunguska
A previous example is the 1972 fireball observed over Utah, Montana and Alberta, but this body never came closer than about 57 km from the Earth and was much smaller (say 5-15 m or so) than the one hypothesized here. The 1972 object produced sonic booms but no damage. It was observed by many and actually filmed. My wife saw it. So, the new hypothesis about Tunguska should be taken seriously and not dismissed out of hand. On Mon, May 11, 2020 at 11:46 AM Frank Cressy via Meteorite-list wrote: > > Maybe someone who has access to the original paper can answer if the author's > modeling takes in account the fall directions of trees under the blast. The > summary doesn't address that. > > Cheers, > > Frank > > > > > > > On Monday, May 11, 2020, 11:00:59 AM PDT, Michael Gilmer via Meteorite-list > wrote: > > > > > > Some new research on the Tunguska event - > https://www.sciencealert.com/scientists-have-a-new-theory-about-the-colossal-tunguska-event-explosion > > > > -- > --- > Galactic Stone & Ironworks : www.galactic-stone.com > Instagram : www.instagram.com/galacticstone > Twitter : www.twitter.com/galacticstone > --- > __ > > Visit our Facebook page https://www.facebook.com/meteoritecentral and the > Archives at http://www.meteorite-list-archives.com > Meteorite-list mailing list > Meteorite-list@meteoritecentral.com > https://pairlist3.pair.net/mailman/listinfo/meteorite-list > __ > > Visit our Facebook page https://www.facebook.com/meteoritecentral and the > Archives at http://www.meteorite-list-archives.com > Meteorite-list mailing list > Meteorite-list@meteoritecentral.com > https://pairlist3.pair.net/mailman/listinfo/meteorite-list -- Alan Rubin Institute of Geophysics and Planetary Physics Department of Earth, Planetary, and Space Sciences University of California 3845 Slichter Hall 603 Charles Young Dr. E Los Angeles, CA 90095-1567 USA office phone: 310-825-3202 fax: 310-206-3051 e-mail: aeru...@ucla.edu website: http://cosmochemists.igpp.ucla.edu/Rubin.html __ Visit our Facebook page https://www.facebook.com/meteoritecentral and the Archives at http://www.meteorite-list-archives.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com https://pairlist3.pair.net/mailman/listinfo/meteorite-list
Re: [meteorite-list] Meteorite reclassification questions
When I initially classified Ningqiang, there were no known CKs. We
classified it as CV3 because that was the closest group, but we noted that
its refractory lithophile element abundances didn't match CV that well.
Later, when we defined the CK group, it became obvious that Ningqiang was
more like CK than CV. Later, upon additional reflection and analyses, we
thought it most likely that Ningqiang was sufficiently different from
normal CKs, that it was probably an ungrouped carbonaceous chondrite that
was closely related to CK and CV.
If you want a meteorite to be reclassified int the Bulletin, you need to
let the folks know (i.e., through Jeff Grossman) that this is warranted and
explain the reasons. Sometimes, the rock will indeed be reclassified and
sometimes it won't. It can be frustrating. I'm not familiar with Hart or
NWA 6047. You could email Tasha Dunn and ask her.
Alan Rubin
On Wed, Mar 13, 2019 at 9:07 PM Michael Doran via Meteorite-list <
meteorite-list@meteoritecentral.com> wrote:
> As a newbie, I've come to rely pretty heavily on the Meteoritical
> Bulletin database for information about particular meteorites as well as to
> look at aggregate data for different types.
>
> I've been somewhat surprised to discover that it is not unusual for
> meteorites to get reclassified and I was wondering if anybody could tell me
> how and under what circumstances a Met Bull entry gets updated to reflect
> new classification information.
>
> Ningqiang is a good example of reclassification updates. The Meteoritical
> Bulletin database entry shows that Ningqiang was originally classified as a
> CV3, per Meteoritical Bulletin #65 (1987) [1]. Then (if I'm interpreting
> the entry correctly) it looks like it was reclassed as a CK3, per the
> Natural History Museum's Catalogue of Meteorites, 5th edition (2000). And
> a subsequent reclassification as C3-ung came per the 7th edition of MetBase
> (2006).
>
> The particular example I had questions about is the entry for Hart, a
> Texas meteorite found in 2010 and that was initially classified as a CK3
> [2]. CK3 is a pretty rare carbonaceous chondrite type and Hart was
> apparently the only meteorite in the U.S. to get that classification.
> However, I recently came across a scientific paper ("Reclassification of
> Hart and Northwest Africa 6047: Criteria for distinguishing between CV and
> CK3 chondrites" [3]) that appears to make a persuasive case for Hart being
> reclassified as a CV3. This paper was published in 2017, but there is no
> update yet in the Met Bull entry.
>
> So my questions are:
>
> 1) Will the Meteoritical Bulletin database entry for Hart eventually get
> updated to reflect a change in classification?
>
> 2) What mechanisms (if any) are in place to keep track of these types of
> reclassifications and make updates? (From what I've seen, there is a
> mechanism for Antarctic meteorites via the Antarctic Meteorite Newsletter.
> See, for example AMN item on reclassifications [4] and subsequent Met Bull
> database entry update [5].)
>
> 3) Is there some body that mediates between competing classification
> claims? E.g. what if the original classifier disagrees with a
> reclassification?
>
> -- Michael
>
> [1] https://www.lpi.usra.edu/meteor/metbull.php?code=16981
>
> [2] https://www.lpi.usra.edu/meteor/metbull.php?code=56555
>
> [3] Dunn, TL, Gross, J. 2017 Reclassification of Hart and Northwest Africa
> 6047: Criteria for distinguishing between CV and CK3 chondrites.
> Meteoritics & Planetary Science 52(11):2412–2423
>
> [4] https://curator.jsc.nasa.gov/antmet/amn/amnfeb10/reclassifications.htm
>
> [5] E.g. for EET 96010
> https://www.lpi.usra.edu/meteor/metbull.php?code=9604
>
> Michael Doran
> Fort Worth, TX
> __
>
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>
--
Alan Rubin
Institute of Geophysics and Planetary Physics
Department of Earth, Planetary, and Space Sciences
University of California
3845 Slichter Hall
603 Charles Young Dr. E
Los Angeles, CA 90095-1567
USA
office phone: 310-825-3202
fax: 310-206-3051
e-mail: aeru...@ucla.edu
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Re: [meteorite-list] Favorite Nininger stories?
I have an anecdote. At the 1984 Meteoritical Society meeting in Albuquerque, there were scientific talks presented by Gary Huss, his father Glenn Hus, and his grandfather Harvey Nininger. This may be the only time that three generations of one family gave scientific talks at the meeting of a scientific society. On Wed, May 23, 2018 at 10:05 AM, Mark Hammergren via Meteorite-list < meteorite-list@meteoritecentral.com> wrote: > I'm giving a brief presentation tomorrow to museum staff members about > Harvey Nininger. Do any of you have any favorite Nininger anecdotes > you'd like to share? Thanks! > __ > > Visit our Facebook page https://www.facebook.com/meteoritecentral and the > Archives at http://www.meteorite-list-archives.com > Meteorite-list mailing list > Meteorite-list@meteoritecentral.com > https://pairlist3.pair.net/mailman/listinfo/meteorite-list > -- Alan Rubin Institute of Geophysics and Planetary Physics Department of Earth, Planetary, and Space Sciences University of California 3845 Slichter Hall 603 Charles Young Dr. E Los Angeles, CA 90095-1567 USA office phone: 310-825-3202 fax: 310-206-3051 e-mail: aeru...@ucla.edu website: http://cosmochemists.igpp.ucla.edu/Rubin.html __ Visit our Facebook page https://www.facebook.com/meteoritecentral and the Archives at http://www.meteorite-list-archives.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com https://pairlist3.pair.net/mailman/listinfo/meteorite-list
Re: [meteorite-list] Michigan Meteor
If anyone is interested, I'm ready and willing to classify the samples. Alan Rubin On Thu, Jan 18, 2018 at 11:24 AM, Bigjohn Shea via Meteorite-list < meteorite-list@meteoritecentral.com> wrote: > They found a few small specimens last I heard. > Did they find the main mass? > > > > Sent using the mail.com mail app > > On 1/18/18 at 1:00 PM, Michael Farmer via Meteorite-list wrote: > > > It has been found > > > > Michael Farmer > > > > > On Jan 18, 2018, at 9:43 AM, Les to Rovy via Meteorite-list < > meteorite-list@meteoritecentral.com> wrote: > > > > > > > > > Sine I'm only 3 hours away was going to go to the area and check out > and see if anyone or anything can be found. > > > > > > Cordially > > > > > > Rick > > > __ > > > > > > Visit our Facebook page https://www.facebook.com/meteoritecentral and > the Archives at http://www.meteorite-list-archives.com > > > Meteorite-list mailing list > > > Meteorite-list@meteoritecentral.com > > > https://pairlist3.pair.net/mailman/listinfo/meteorite-list > > > > __ > > > > Visit our Facebook page https://www.facebook.com/meteoritecentral and > the Archives at http://www.meteorite-list-archives.com > > Meteorite-list mailing list > > Meteorite-list@meteoritecentral.com > > https://pairlist3.pair.net/mailman/listinfo/meteorite-list > __ > > Visit our Facebook page https://www.facebook.com/meteoritecentral and the > Archives at http://www.meteorite-list-archives.com > Meteorite-list mailing list > Meteorite-list@meteoritecentral.com > https://pairlist3.pair.net/mailman/listinfo/meteorite-list > -- Alan Rubin Institute of Geophysics and Planetary Physics Department of Earth, Planetary, and Space Sciences University of California 3845 Slichter Hall 603 Charles Young Dr. E Los Angeles, CA 90095-1567 USA office phone: 310-825-3202 fax: 310-206-3051 e-mail: aeru...@ucla.edu website: http://cosmochemists.igpp.ucla.edu/Rubin.html __ Visit our Facebook page https://www.facebook.com/meteoritecentral and the Archives at http://www.meteorite-list-archives.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com https://pairlist3.pair.net/mailman/listinfo/meteorite-list
Re: [meteorite-list] Quartz on meteorites
If any of you want an old reference, there is an abstract by Grant from 1968: GRANT, R. W., 1968. The occurrence of silica minerals in meteorites. Program 31st Meeting Meteoritical Sot., Cambridge, Mass., 1968 (abstract). Alan Rubin On Mon, Sep 25, 2017 at 9:48 AM, André Moutinho <mouti...@gmail.com> wrote: > Hello all, > > Morro do Rocio is a Brazilian meteorite that sílica was found: > http://adsabs.harvard.edu/full/1985Metic..20..467F > > Best > > Andre > > > > De: Meteorite-list > [mailto:meteorite-list-boun...@meteoritecentral.com] Em nome de ALAN > RUBIN via Meteorite-list > Enviada em: sábado, 23 de setembro de 2017 21:28 > Para: Abdelfattah Gharrad <agharra...@yahoo.com> > Cc: Meteoritecentral List <meteorite-list@meteoritecentral.com> > Assunto: Re: [meteorite-list] Quartz on meteorites > > > > A few meteorites do contain rare grains of SiO2 including tridymite, > quartz and cristobalite, but generally these grains are quite small > and intergrown with other silicate phases. Some IVA irons contain a > few blades of trydimite, but if you see a rock with several percent or > more of quartz grains that are millimeter size or larger, it will not > be a meteorite. > > > > On Sat, Sep 23, 2017 at 4:46 PM, Abdelfattah Gharrad via > Meteorite-list <meteorite-list@meteoritecentral.com> wrote: > > Hello members, > > I really want to post my question about quartz longtimes ago, what I > learned that if one sees quartz on a stone then the stone is not > meteorite. > in my knowledge there are different types of quartz and whose chemical > formula is SiO2. > > habitually no quartz in the meteorites but if there is in a meteorite > then it is a rare stone and whose classification differs from other > meteorites and testimony of another planet it's just opinion. > > I think that the meteorites have chemical compositions like the > terrestrial stones (magmatic, volcanic ...). the probability that a > meteorite contains SiO2 is not zero. > > if there is a clarification please. > > Thanks, > Abdelfattah. > __ > > Visit our Facebook page https://www.facebook.com/meteoritecentral and > the Archives at http://www.meteorite-list-archives.com > Meteorite-list mailing list > Meteorite-list@meteoritecentral.com > https://pairlist3.pair.net/mailman/listinfo/meteorite-list > > > > > > -- > > Alan Rubin > > Institute of Geophysics and Planetary Physics > > Department of Earth, Planetary, and Space Sciences > > University of California > > 3845 Slichter Hall > > 603 Charles Young Dr. E > > Los Angeles, CA 90095-1567 > > USA > > > > office phone: 310-825-3202 > > fax: 310-206-3051 > > e-mail: aeru...@ucla.edu > > website: http://cosmochemists.igpp.ucla.edu/Rubin.html > -- Alan Rubin Institute of Geophysics and Planetary Physics Department of Earth, Planetary, and Space Sciences University of California 3845 Slichter Hall 603 Charles Young Dr. E Los Angeles, CA 90095-1567 USA office phone: 310-825-3202 fax: 310-206-3051 e-mail: aeru...@ucla.edu website: http://cosmochemists.igpp.ucla.edu/Rubin.html __ Visit our Facebook page https://www.facebook.com/meteoritecentral and the Archives at http://www.meteorite-list-archives.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com https://pairlist3.pair.net/mailman/listinfo/meteorite-list
Re: [meteorite-list] Quartz on meteorites
A few meteorites do contain rare grains of SiO2 including tridymite, quartz and cristobalite, but generally these grains are quite small and intergrown with other silicate phases. Some IVA irons contain a few blades of trydimite, but if you see a rock with several percent or more of quartz grains that are millimeter size or larger, it will not be a meteorite. On Sat, Sep 23, 2017 at 4:46 PM, Abdelfattah Gharrad via Meteorite-list < meteorite-list@meteoritecentral.com> wrote: > Hello members, > > I really want to post my question about quartz longtimes ago, what I > learned that if one sees quartz on a stone then the stone is not meteorite. > in my knowledge there are different types of quartz and whose chemical > formula is SiO2. > > habitually no quartz in the meteorites but if there is in a meteorite then > it is a rare stone and whose classification differs from other meteorites > and testimony of another planet it's just opinion. > > I think that the meteorites have chemical compositions like the > terrestrial stones (magmatic, volcanic ...). the probability that a > meteorite contains SiO2 is not zero. > > if there is a clarification please. > > Thanks, > Abdelfattah. > __ > > Visit our Facebook page https://www.facebook.com/meteoritecentral and the > Archives at http://www.meteorite-list-archives.com > Meteorite-list mailing list > Meteorite-list@meteoritecentral.com > https://pairlist3.pair.net/mailman/listinfo/meteorite-list > -- Alan Rubin Institute of Geophysics and Planetary Physics Department of Earth, Planetary, and Space Sciences University of California 3845 Slichter Hall 603 Charles Young Dr. E Los Angeles, CA 90095-1567 USA office phone: 310-825-3202 fax: 310-206-3051 e-mail: aeru...@ucla.edu website: http://cosmochemists.igpp.ucla.edu/Rubin.html __ Visit our Facebook page https://www.facebook.com/meteoritecentral and the Archives at http://www.meteorite-list-archives.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com https://pairlist3.pair.net/mailman/listinfo/meteorite-list
Re: [meteorite-list] Articles About Meteorites And Asteroids
Is this the first published description of a falling meteorite? It's from the Aeneid Book II: The old man had barely spoken when, with a sudden crash, it thundered on the left, and a star, through the darkness, slid from the sky, and flew, trailing fire, in a burst of light. We watched it glide over the highest rooftops, and bury its brightness, and the sign of its passage, in the forests of Mount Ida: then the furrow of its long track gave out a glow, and, all around, the place smoked with sulphur. On Fri, Jan 27, 2017 at 6:16 PM, Paul via Meteorite-list < meteorite-list@meteoritecentral.com> wrote: > Meteorite Studies Reveal Surprises About Earth's Formation > By Elizabeth Howell, SpaceCom, January 26, 2017 > http://www.space.com/35468-earth-building-blocks-different- > than-thought.html > > Nice picture of Meteorite On Mars > > Curiosity Finds An(other) Alien Visitor on Mars > Earth Isn't the Only Planet Hit by Meteorites. Mars Gets > Them, Too. by Phil Plait, Blog-Slate Magazine, January 23, 2017 > http://www.slate.com/blogs/bad_astronomy/2017/01/23/curiosit > y_sees_a_meteorite_on_the_surface_of_mars.html > > This image was taken by Mastcam: Right (MAST_RIGHT) > onboard NASA's Mars rover Curiosity on Sol 1577 > (2017-01-12 11:21:52 UTC). NASA/JPL-Caltech/MSSS > http://mars.nasa.gov/msl/multimedia/raw/?rawid=1577MR0080320 > 000800289E01_DXXX=1577 > > Deflecting Asteroids > > Objective: To deflect asteroids, thus preventing their collision > with Earth Space Daily, Madrid, Spain, January 27, 2017 > http://www.spacedaily.com/reports/Objective_To_deflect_aster > oids_thus_preventing_their_collision_with_Earth_999.html > > Scientists working on deflecting asteroids headed for Earth > The Indian Express, January 27, 2017 > http://indianexpress.com/article/technology/science/scientis > ts-working-on-deflecting-asteroids-headed-for-earth-4493719/ > > Yours, > > Paul H. > > __ > > Visit our Facebook page https://www.facebook.com/meteoritecentral and the > Archives at http://www.meteorite-list-archives.com > Meteorite-list mailing list > Meteorite-list@meteoritecentral.com > https://pairlist3.pair.net/mailman/listinfo/meteorite-list > -- Alan Rubin Institute of Geophysics and Planetary Physics Department of Earth, Planetary, and Space Sciences University of California 3845 Slichter Hall 603 Charles Young Dr. E Los Angeles, CA 90095-1567 USA office phone: 310-825-3202 fax: 310-206-3051 e-mail: aeru...@ucla.edu website: http://cosmochemists.igpp.ucla.edu/Rubin.html __ Visit our Facebook page https://www.facebook.com/meteoritecentral and the Archives at http://www.meteorite-list-archives.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com https://pairlist3.pair.net/mailman/listinfo/meteorite-list
Re: [meteorite-list] Captain's Log - Jeff Grossman(?)
It is indeed. On Thu, Sep 8, 2016 at 8:23 AM, Kevin Kichinka via Meteorite-list < meteorite-list@meteoritecentral.com> wrote: > Team Meteorite: > > An article today on CNN.com regarding a sample recovery NASA mission > designated OSIRIS-REx to asteroid 'Bennu' quotes Program Scientist Jeff > Grossman. > > Is that THE/'our' Jeff Grossman? > > Kevin Kichinka > > Seemingly swarming with scorpions and snakes near Puriscal, Costa Rica > > "The Art of Collecting Meteorites" available on Amazon or Nook > > __ > > Visit our Facebook page https://www.facebook.com/meteoritecentral and the > Archives at http://www.meteorite-list-archives.com > Meteorite-list mailing list > Meteorite-list@meteoritecentral.com > https://pairlist3.pair.net/mailman/listinfo/meteorite-list > > -- Alan Rubin Institute of Geophysics and Planetary Physics Department of Earth, Planetary, and Space Sciences University of California 3845 Slichter Hall 603 Charles Young Dr. E Los Angeles, CA 90095-1567 USA office phone: 310-825-3202 fax: 310-206-3051 e-mail: aeru...@ucla.edu website: http://cosmochemists.igpp.ucla.edu/Rubin.html __ Visit our Facebook page https://www.facebook.com/meteoritecentral and the Archives at http://www.meteorite-list-archives.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com https://pairlist3.pair.net/mailman/listinfo/meteorite-list
Re: [meteorite-list] Meteor wine
Meteor vineyard is selling a 3-pack of their current release of Meteor Wine for $375.00, still steep, but a lot less than $200 a bottle. You have to join their mailing list (which is free) to enable you to purchase their products. I've never tried it, so I cannot evaluate its quality. Just FYI. On Sat, Jul 2, 2016 at 12:53 PM, Edwin Thompson via Meteorite-list < meteorite-list@meteoritecentral.com> wrote: > Hello list members, > > I am searching for a bottle of Meteor wine. > A friend would like to include one in his public meteorite display. I have > searched through known wine buying venues and found a bottle in California, > but they want $200.00 for one bottle, a bit steep for this project. > I have seen several different bottles with meteors on the label over the > years. If you have a spare bottle please kindly contact me. The bottle > can be empty of contents and could be returned after being displayed. > Purchase or trade could be considered. Just doing a favor for a long time > friend. > > Thanks, > > Edwin Thompson > etmeteori...@hotmail.com > > Viva Le Tour! > > __ > > Visit our Facebook page https://www.facebook.com/meteoritecentral and the > Archives at http://www.meteorite-list-archives.com > Meteorite-list mailing list > Meteorite-list@meteoritecentral.com > https://pairlist3.pair.net/mailman/listinfo/meteorite-list > -- Alan Rubin Institute of Geophysics and Planetary Physics Department of Earth, Planetary, and Space Sciences University of California 3845 Slichter Hall 603 Charles Young Dr. E Los Angeles, CA 90095-1567 USA office phone: 310-825-3202 fax: 310-206-3051 e-mail: aeru...@ucla.edu website: http://cosmochemists.igpp.ucla.edu/Rubin.html __ Visit our Facebook page https://www.facebook.com/meteoritecentral and the Archives at http://www.meteorite-list-archives.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com https://pairlist3.pair.net/mailman/listinfo/meteorite-list
[meteorite-list] AD - Magazine with first use of Meteor-wrong?
As far as I know, one of the first published uses of the term "Meteor-wrong" was by Edward Olsen in the April 1979 issue of the Field Museum of Natural History Bulletin. He wrote an article with that title discussing some of his experiences as the meteorite curator at the Field Museum in Chicago. Olsen was my M.S. thesis adviser at the time. Among other features in that magazine issue is a reprint of a 1948 article on butterflies by Vladimir Nabokov, who later went on to write Lolita. There is also an article of mine on time and relativity. I have extra copies of that issue and will part with them for $12.00 a piece. I'll pay the postage. I'll also be happy to sign the front page of my article. If you are interested, you can send a check made out to me at the address below along with your name and address. Alternatively, you can send money via PayPal using my e-mail address: aeru...@ucla.edu If you do that, please include your name and address in the note along with the payment. I'll sign my article and send the issue out to you. -- Alan Rubin Institute of Geophysics and Planetary Physics Department of Earth, Planetary, and Space Sciences University of California Los Angeles, CA 90095-1567 USA office phone: 310-825-3202 fax: 310-206-3051 e-mail: aeru...@ucla.edu website: http://cosmochemists.igpp.ucla.edu/Rubin.html __ Visit our Facebook page https://www.facebook.com/meteoritecentral and the Archives at http://www.meteorite-list-archives.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com https://pairlist3.pair.net/mailman/listinfo/meteorite-list
Re: [meteorite-list] petrological type
Since Van Schmus and Wood (1967), the group/petrologic type designation has been entrenched (i.e., LL3.0, H4, L6), that it would be impossible to purge. So, calling Semarkona LL T3 just won't work -- no one would adopt it as a new convention. If we wanted to call Semarkona LL3.00 A2.8, that might be okay, but you would have to convince people first that a two-tier system is needed. It is probably best to exclude weathering and shock stage since we cannot designate every property in a classification (e.g., average olivine Fa content, cosmic-ray exposure age, oxygen-isotopic composition, chondrule size, etc.). A problem of course is that it may be difficult to disentangle thermal metamorphism from aqueous alteration, leaving a researcher baffled as to what to designate a particular rock. It would be better to leave out a classificatory parameter and to just guess and have the rock misclassified. Alan Rubin Institute of Geophysics and Planetary Physics University of California 3845 Slichter Hall 603 Charles Young Dr. E Los Angeles, CA 90095-1567 office phone: 310-825-3202 fax: 310-206-3051 e-mail: aeru...@ucla.edu website: http://cosmochemists.igpp.ucla.edu/Rubin.html -Original Message- From: meteorite-list-boun...@meteoritecentral.com [mailto:meteorite-list-boun...@meteoritecentral.com] On Behalf Of Mark Bowling Sent: Saturday, April 12, 2014 8:13 AM To: Meteorite List Subject: Re: [meteorite-list] petrological type Would the following convention work? Letter designations would be used for each type of metamorphism. T for Thermal and A for aqueous. For a range of values, a dash could be used. So your example of Semarkona would end up as follows: Semarkona LL T3 A2.8-2.9. Using letter designations is already done for shock metamorphism and weathering grade. So when adding those, Semarkona would become (i'm guessing): Semarkona LL T3 A2.8-2.9 S? W0 It gets to be rather cumbersome, as you say, but if it were used, one could then quickly get an idea of the geological history of a particular specimen, just from the classification. Here is Dho 1073 as an example (and again I'm guessing on the values): Dho 1073 CV T3 A2 S2 W2-3 Capturing the order in which they occur could also be done (if you wanted to get that much information packed into a classification scheme). Something earlier would be placed first. If concurrent, they are linked with a slash. So the prior example, thermal metamorphism would have happened first. If aqueous alteration was first, then it would be designated as: Dho 1073 CV A2 T3 S2 W2-3 If A T happened together, it would be: Dho 1073 CV T3/A2 S2 W2-3 But I'm not sure if that is practical - if the order is not always clear (or if effort to make a determination is rarely given), specifying order would be unreliable and inconsistent. Such information, if known, would be better communicated in the writeup. Next, if any of these types of metamorphism cannot or never occur in a particular class, you can leave out that letter. I would think it's safer to not assume it doesn't/cannot occur (simply because we don't have an example), and instead use a question mark in place of a number. e.g. Golden Mile H T4 A? S1 W1 (Congratulations Twink!). It's pretty tedious and intimidating, but with a little practice, people would soon be able to understand quite a bit more about a rock just by seeing the classification. Plus it could always be simplified, whereby a stone could be designated as an L3.0. And people would pretty much understand what that means or could imagine what it would look like. Or for those unconcerned, they could use everything as it now is, while scientists could adhere to the above convention in order to better communicate with each other. This is a interesting topic, thanks for kicking it off Francesco! Have fun! Mark - Original Message - From: Alan Rubin aeru...@ucla.edu To: 'Mark Bowling' mina...@yahoo.com; meteorite-list@meteoritecentral.com Cc: Sent: Friday, April 11, 2014 10:10 PM Subject: Re: [meteorite-list] petrological type Several people have informally suggested a two-tier system. It would work something like this. For example, on a metamorphic scale, Semarkona is type 3.00, but on an independent aqueous alteration scale it would be 2.8 or 2.9. Similarly, CR chondrites could all be 3.0 on a metamorphic scale, but range from 2.0 to 2.8 on an aqueous alteration scale. This is admittedly cumbersome, but it would be fairly useful. However, there are some carbonaceous chondrites that seem to have been altered and then metamorphosed; they would be hard to deal with. Also, if a rock is hydrothermally altered (i.e., subjected to metamorphic heating and aqueous alteration at the same time), that would also not be covered by such a scheme. Fitting complex rocks into classificatory straightjackets might obscure more than it reveals. Alan Alan Rubin Institute of Geophysics and Planetary Physics University
Re: [meteorite-list] petrological type
Important meteorites should be well described and a lot of info should be available in the detailed characterization. For now, most people are comfortable with just the group/type designation with all other measured parameters and interpretations being left for the detailed description. You can rest assured that not every researcher would agree that Semarkona has been aqueously altered to an extent equivalent to a 2.8 especially since such a scale for ordinary chondrites is currently undefined. What is needed is the demonstration that ordinary chondrites have been aqueously altered to different extents, the numerical breakdown into different degrees of alteration and an unambiguous definition of what each stage designates. No one has done this and it would be hard. What we have now a number of observations: e.g., (a) the Semarkona matrix contains some smectite, (b) the opaque phases in the Semarkona matrix generally lack kamacite and instead consist mainly of carbide, Ni-rich metal, pentlandite, troilite and magnetite, (c) many type-3 OC contain RP and C chondrules that have bleached rims reflecting aqueous alteration, (d) hydration of glass in some Semarkona chondrules, and (e) alteration of some chondrule mesostasis regions. Other type-3 OC are more poorly studied than Semarkona and we are quite far from creating a comprehensive alteration scheme. Alan Rubin Institute of Geophysics and Planetary Physics University of California 3845 Slichter Hall 603 Charles Young Dr. E Los Angeles, CA 90095-1567 office phone: 310-825-3202 fax: 310-206-3051 e-mail: aeru...@ucla.edu website: http://cosmochemists.igpp.ucla.edu/Rubin.html -Original Message- From: meteorite-list-boun...@meteoritecentral.com [mailto:meteorite-list-boun...@meteoritecentral.com] On Behalf Of Jim Wooddell Sent: Saturday, April 12, 2014 12:08 PM To: meteorite-list@meteoritecentral.com Subject: Re: [meteorite-list] petrological type Hi Alan and all, Is not the description/s part of the classification so that the researcher can better describe what is found without having to baffle over a number or preset definition that might...kind of...come close to what is found?? Jim On 4/12/2014 10:01 AM, Alan Rubin wrote: Since Van Schmus and Wood (1967), the group/petrologic type designation has been entrenched (i.e., LL3.0, H4, L6), that it would be impossible to purge. So, calling Semarkona LL T3 just won't work -- no one would adopt it as a new convention. If we wanted to call Semarkona LL3.00 A2.8, that might be okay, but you would have to convince people first that a two-tier system is needed. It is probably best to exclude weathering and shock stage since we cannot designate every property in a classification (e.g., average olivine Fa content, cosmic-ray exposure age, oxygen-isotopic composition, chondrule size, etc.). A problem of course is that it may be difficult to disentangle thermal metamorphism from aqueous alteration, leaving a researcher baffled as to what to designate a particular rock. It would be better to leave out a classificatory parameter and to just guess and have the rock misclassified. Alan Rubin Institute of Geophysics and Planetary Physics University of California 3845 Slichter Hall 603 Charles Young Dr. E Los Angeles, CA 90095-1567 office phone: 310-825-3202 fax: 310-206-3051 e-mail: aeru...@ucla.edu website: http://cosmochemists.igpp.ucla.edu/Rubin.html -- Jim Wooddell jim.woodd...@suddenlink.net http://pages.suddenlink.net/chondrule/ __ Visit the Archives at http://www.meteorite-list-archives.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list __ Visit the Archives at http://www.meteorite-list-archives.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
Re: [meteorite-list] petrological type
Several people have informally suggested a two-tier system. It would work something like this. For example, on a metamorphic scale, Semarkona is type 3.00, but on an independent aqueous alteration scale it would be 2.8 or 2.9. Similarly, CR chondrites could all be 3.0 on a metamorphic scale, but range from 2.0 to 2.8 on an aqueous alteration scale. This is admittedly cumbersome, but it would be fairly useful. However, there are some carbonaceous chondrites that seem to have been altered and then metamorphosed; they would be hard to deal with. Also, if a rock is hydrothermally altered (i.e., subjected to metamorphic heating and aqueous alteration at the same time), that would also not be covered by such a scheme. Fitting complex rocks into classificatory straightjackets might obscure more than it reveals. Alan Alan Rubin Institute of Geophysics and Planetary Physics University of California 3845 Slichter Hall 603 Charles Young Dr. E Los Angeles, CA 90095-1567 office phone: 310-825-3202 fax: 310-206-3051 e-mail: aeru...@ucla.edu website: http://cosmochemists.igpp.ucla.edu/Rubin.html -Original Message- From: meteorite-list-boun...@meteoritecentral.com [mailto:meteorite-list-boun...@meteoritecentral.com] On Behalf Of Mark Bowling Sent: Friday, April 11, 2014 10:01 PM To: meteorite-list@meteoritecentral.com Subject: Re: [meteorite-list] petrological type Are there any better alternatives that could someday replace the current one, and do you have any references/links for them? Thanks, Mark From: Jeff Grossman jngross...@gmail.com To: meteorite-list@meteoritecentral.com Sent: Friday, April 11, 2014 5:22 PM Subject: Re: [meteorite-list] petrological type Answer: you can't. The classification scheme is lousy. Jeff On 4/11/2014 1:21 PM, Michael Mulgrew wrote: Two sequences, one for aqueous alteration and one for thermal metamorphism (http://www.meteoritemarket.com/PetTypeGroup.jpg). Makes one wonder how we would classify a meteorite that is both thermally and aqueously altered... Michael in so. Cal. IMCA 3963 On Fri, Apr 11, 2014 at 10:14 AM, Francesco Moser coj...@tiscali.it wrote: Hello, I have a question about chondrites' petrological type number assigned after the letters (like H, L, CM or CR ...). I have just read something in internet but I think I have misunderstood something. Are the numbers from 1 to 7 in sequence or there are two different sequences: 1 to 2 - 3 to 7 ?? 1 to 2 is for the aqueous alteration degree in carbonaceous chodrites (1 high degree, 2 low degree) 3 to 7 is for thermal metamorphism degree? Thanks a lot Ciao x Francesco __ Visit the Archives at http://www.meteorite-list-archives.com/ Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list __ Visit the Archives at http://www.meteorite-list-archives.com/ Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list __ Visit the Archives at http://www.meteorite-list-archives.com/ Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list __ Visit the Archives at http://www.meteorite-list-archives.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list __ Visit the Archives at http://www.meteorite-list-archives.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
Re: [meteorite-list] is it a meteorite
This refers to modeling, not actual observations. Gladman and Coffey (2009) MPS 44, 285-291 calculated that Mercury ejecta could achieve independent orbits and re-accrete to Mercury after several million years. Alan Rubin Institute of Geophysics and Planetary Physics University of California 3845 Slichter Hall 603 Charles Young Dr. E Los Angeles, CA 90095-1567 office phone: 310-825-3202 fax: 310-206-3051 e-mail: aeru...@ucla.edu website: http://cosmochemists.igpp.ucla.edu/Rubin.html -Original Message- From: meteorite-list-boun...@meteoritecentral.com [mailto:meteorite-list-boun...@meteoritecentral.com] On Behalf Of cdtuc...@cox.net Sent: Wednesday, April 9, 2014 6:37 AM To: Alan Rubin; 'Jim Wooddell'; meteorite-list@meteoritecentral.com Subject: Re: [meteorite-list] is it a meteorite Alan, You said; Interestingly, some studies have concluded that rocks blasted off of Mercury spend millions of years in independent heliocentric orbits before accreting once again with Mercury. How did our probes reveal enough data to reach such a conclusion? Thanks, Carl Meteoritemax -- Love Life Alan Rubin aeru...@ucla.edu wrote: The more general question is how we would distinguish a terrestrial meteorite found on Earth 9as opposed to one found in the lunar regolith). Unless it was an observed fall, the rock would have to have a fusion crust for us to notice it in the first place. It would have been exposed to cosmic rays (gauged by measuring its cosmogenic nuclides) and it should have the isotopic compositions of terrestrial rocks. Presumably, the rock would have been extensively shocked or completely melted for it to have been launched off the Earth to begin with. Interestingly, some studies have concluded that rocks blasted off of Mercury spend millions of years in independent heliocentric orbits before accreting once again with Mercury. Alan Rubin Institute of Geophysics and Planetary Physics University of California 3845 Slichter Hall 603 Charles Young Dr. E Los Angeles, CA 90095-1567 office phone: 310-825-3202 fax: 310-206-3051 e-mail: aeru...@ucla.edu website: http://cosmochemists.igpp.ucla.edu/Rubin.html -Original Message- From: meteorite-list-boun...@meteoritecentral.com [mailto:meteorite-list-boun...@meteoritecentral.com] On Behalf Of Jim Wooddell Sent: Tuesday, April 8, 2014 2:53 PM To: meteorite-list@meteoritecentral.com Subject: Re: [meteorite-list] is it a meteorite So, let's say there is one.a chunk of hematite. What tests could be performed to 1. Prove it was in Space. 2. Originally from Earth. ??? Radionuclide? Jim -- Jim Wooddell jim.woodd...@suddenlink.net http://pages.suddenlink.net/chondrule/ __ Visit the Archives at http://www.meteorite-list-archives.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list __ Visit the Archives at http://www.meteorite-list-archives.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list __ Visit the Archives at http://www.meteorite-list-archives.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list __ Visit the Archives at http://www.meteorite-list-archives.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
Re: [meteorite-list] is it a meteorite
Yes, the word itself refers to the meteorite (or, more properly, the meteoroid) and an artificial body would be a spacecraft of some sort. Alan Rubin Institute of Geophysics and Planetary Physics University of California 3845 Slichter Hall 603 Charles Young Dr. E Los Angeles, CA 90095-1567 office phone: 310-825-3202 fax: 310-206-3051 e-mail: aeru...@ucla.edu website: http://cosmochemists.igpp.ucla.edu/Rubin.html -Original Message- From: meteorite-list-boun...@meteoritecentral.com [mailto:meteorite-list-boun...@meteoritecentral.com] On Behalf Of Mendy Ouzillou Sent: Tuesday, April 8, 2014 12:18 PM To: Jeff Grossman; meteorite-list@meteoritecentral.com Subject: Re: [meteorite-list] is it a meteorite OK, so some questions regarding the definition: 1) What would be considered an artificial body? 2) I am 99.9% sure that the word itself refers to the meteorite (as opposed to the body on which the meteorite lands). Correct? Mendy Ouzillou From: Jeff Grossman jngross...@gmail.com To: meteorite-list@meteoritecentral.com Sent: Tuesday, April 8, 2014 10:38 AM Subject: Re: [meteorite-list] is it a meteorite Yes, Alan and I would call this object a real meteorite, but not tektites, which never escaped from Earth's gravity well. It's a bit of a stretch and model dependent, but in a way, lunar meteorites may be considered as this type of meteorite. Jeff On 4/8/2014 7:18 AM, Peter Scherff wrote: Hi, According to Alan E. Rubin Jeffrey N. Grossman: A meteorite is a natural, solid object larger than 10 µm in size, derived from a celestial body, that was transported by natural means from the body on which it formed to a region outside the dominant gravitational influence of that body and that later collided with a natural or artificial body larger than itself (even if it was the same body from which it was launched). Using that definition I would say that your rock should be called a meteorite. I also think that a cool name for a new class of meteorites would need to be created. I just hope that we could have that class created before 5 examples of it were recognized. Thanks, Peter -Original Message- From: meteorite-list-boun...@meteoritecentral.com [mailto:meteorite-list-boun...@meteoritecentral.com] On Behalf Of Mark Ford Sent: Tuesday, April 08, 2014 3:28 AM To: Meteorite-list@meteoritecentral.com Subject: Re: [meteorite-list] is it a meteorite IMHO - This should most likely be called 'Earthite'. A whole new class of rocks distinct from meteorites, which so far we don't have any of (unless anyone knows different!?). Or they could just be known as Tektites, since that is essentially what the consensus is on Tektites. Though I would put Tektites in the group of Ancient impact glasses rather than actual fusion crusted rocks from earth. Mark -Original Message- From: meteorite-list-boun...@meteoritecentral.com [mailto:meteorite-list-boun...@meteoritecentral.com] On Behalf Of Chris Sent: 08 April 2014 06:15 To: meteorite-list@meteoritecentral.com Subject: [meteorite-list] is it a meteorite Suppose a fusion crusted stone is found shortly after a fireball. When examined it shows a celestial age of a few million years and a relatively short formation age. More examination shows it to be a stone formed on earth, ejected into space and returned here. Is it meteorite or a meteorwrong. Or something in between? __ Visit the Archives at http://www.meteorite-list-archives.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list __ Visit the Archives at http://www.meteorite-list-archives.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list --- This email is free from viruses and malware because avast! Antivirus protection is active. http://www.avast.com __ Visit the Archives at http://www.meteorite-list-archives.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list __ Visit the Archives at http://www.meteorite-list-archives.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list __ Visit the Archives at http://www.meteorite-list-archives.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list __ Visit the Archives at http://www.meteorite-list-archives.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo
Re: [meteorite-list] is it a meteorite
The more general question is how we would distinguish a terrestrial meteorite found on Earth 9as opposed to one found in the lunar regolith). Unless it was an observed fall, the rock would have to have a fusion crust for us to notice it in the first place. It would have been exposed to cosmic rays (gauged by measuring its cosmogenic nuclides) and it should have the isotopic compositions of terrestrial rocks. Presumably, the rock would have been extensively shocked or completely melted for it to have been launched off the Earth to begin with. Interestingly, some studies have concluded that rocks blasted off of Mercury spend millions of years in independent heliocentric orbits before accreting once again with Mercury. Alan Rubin Institute of Geophysics and Planetary Physics University of California 3845 Slichter Hall 603 Charles Young Dr. E Los Angeles, CA 90095-1567 office phone: 310-825-3202 fax: 310-206-3051 e-mail: aeru...@ucla.edu website: http://cosmochemists.igpp.ucla.edu/Rubin.html -Original Message- From: meteorite-list-boun...@meteoritecentral.com [mailto:meteorite-list-boun...@meteoritecentral.com] On Behalf Of Jim Wooddell Sent: Tuesday, April 8, 2014 2:53 PM To: meteorite-list@meteoritecentral.com Subject: Re: [meteorite-list] is it a meteorite So, let's say there is one.a chunk of hematite. What tests could be performed to 1. Prove it was in Space. 2. Originally from Earth. ??? Radionuclide? Jim -- Jim Wooddell jim.woodd...@suddenlink.net http://pages.suddenlink.net/chondrule/ __ Visit the Archives at http://www.meteorite-list-archives.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list __ Visit the Archives at http://www.meteorite-list-archives.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
Re: [meteorite-list] Did All CI's Originate on Mars?
Several groups of meteorites have similar O isotopes, for example, the Earth, Moon, EH chondrites, EL chondrites, aubrites all have the same O-isotopic compositions. No one would say that they are all derived from the same parent body. All that means is that the preponderance of material is from the same O-isotopic reservoir. One does not expect chondritic meteorites to be derived from a differentiated body. The igneous processes involved in differentiation fractionate the chemical composition of the constitutent rocks in various ways, making them distinctly non-chondritic. This is particularly true of REE. The CI chondrites have many similarities to CMs, indicating that they formed by a similar process, presumably on a similar asteroid. These textural similarities include the olivine Fa-CaO distributions which are similar to those in CM chondrules and CM isolated olivine grains. There are also vary rare chondrule fragments, CAI fragments and even one CAI in CI chondrites, indicating that they are real chondrites in terms of texture as well as composition. There is no good reason to believe that they are from Mars. Alan Rubin Institute of Geophysics and Planetary Physics University of California 3845 Slichter Hall 603 Charles Young Dr. E Los Angeles, CA 90095-1567 phone: 310-825-3202 e-mail: aeru...@ucla.edu website: http://cosmochemists.igpp.ucla.edu/Rubin.html - Original Message - From: Kevin Kichinka mars...@gmail.com To: meteorite-list@meteoritecentral.com Sent: Saturday, March 15, 2014 4:51 PM Subject: [meteorite-list] Did All CI's Originate on Mars? Team Meteorite: David Weir just shared this paper with me. He exuded shock and awe. I read it, and although not doing further data follow-up, I am sitting here with the sun setting in the mango orchard, stunned. Can we get some other discussion about this? http://www.hou.usra.edu/meetings/lpsc2014/pdf/1143.pdf Kevin Kichinka mars...@gmail.com Rio del Oro, Santa Ana, Costa Rica The Art of Collecting Meteorites' available as an eBook on Amazon/Barnes and Noble The Global Meteorite Price Report - 2015 available in December, 2014 __ Visit the Archives at http://www.meteorite-list-archives.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list __ Visit the Archives at http://www.meteorite-list-archives.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
Re: [meteorite-list] NWA 8330 (LL3)
NWA 8330 is a little more recrystallized than Ragland, although I concur that they are both likely from the same parent asteroid. Alan Rubin Institute of Geophysics and Planetary Physics University of California 3845 Slichter Hall 603 Charles Young Dr. E Los Angeles, CA 90095-1567 phone: 310-825-3202 e-mail: aeru...@ucla.edu website: http://cosmochemists.igpp.ucla.edu/Rubin.html - Original Message - From: Bernd V. Pauli bernd.pa...@paulinet.de To: meteorite-list@meteoritecentral.com Sent: Saturday, March 15, 2014 4:42 PM Subject: [meteorite-list] NWA 8330 (LL3) Hello again, NWA 8330 looks a lot like Ragland (LL3.4) ... both chondrule-wise and bleached chondrule-wise. I wouldn't be too surprised if they had a common parent body! What a meteorite! Bernd __ Visit the Archives at http://www.meteorite-list-archives.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list __ Visit the Archives at http://www.meteorite-list-archives.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
Re: [meteorite-list] Ungrouped Achondrite Prices (NWA 7325 andothers)
Carl mentioned a CK parent body. I doubt that there is such a thing. In a recent paper, the UCLA folks suggested that CKs were just metamorphosed CVs. I wrote a column in Meteorite about that not too long ago as well. If this is correct then a CK parent body would really likely be a CV-CK parent body. Carl's idea then becomes a little more complicated. Either you have to make the achondrite straight from a CV or you have to metamorphose the CV material (perhaps by collisions, perhaps by slow heating via 26Al) to make a CK and then melt that. It seems simpler to skip the CK step. Alan Alan Rubin Institute of Geophysics and Planetary Physics University of California 3845 Slichter Hall 603 Charles Young Dr. E Los Angeles, CA 90095-1567 phone: 310-825-3202 e-mail: aeru...@ucla.edu website: http://cosmochemists.igpp.ucla.edu/Rubin.html - Original Message - From: Carl Agee a...@unm.edu To: Galactic Stone Ironworks meteoritem...@gmail.com Cc: Meteorite List meteorite-list@meteoritecentral.com Sent: Wednesday, March 12, 2014 9:06 PM Subject: Re: [meteorite-list] Ungrouped Achondrite Prices (NWA 7325 andothers) Hi Mike and All: Achondrite-ung one of my favorite things! Also the enigmatic groupings like ACA, LOD, WIN, BRAC, URE, fascinating! From what I have seen and heard about NWA 7325 -- simply amazing. The problem has nothing to do with these wonderful achondrites, the problem is our ignorance of their possible parent bodies. Martian and lunar meteorites are of the highest scientific value, not because they are better meteorites, but because we know enough about their parent bodies to make the meteorite - parent body connection and thereby they become the equivalent of geological sample returns. If NASA hadn't sent missions to the Moon or Mars we would most likely not recognize these meteorites as lunar and Martian. So, the problem with Mercurian meteorites is not whether they do or don't exist, the problem is our fragmentary understanding of the planet Mercury and our inability, at this time, to make the parent body - meteorite connection. Yes, Mercury Messenger has given us new insight into the make up of the Mercurian crust, but the data are simply still not good enough to be useful for unequivocal meteorite matching. So even if we have a meteorite from Mercury somewhere in the world's collections right now, we won't know it until Mercury is better known. Part of the problem is that Mercury possesses no true atmosphere. Remember, the strongest evidence for martian meteorites being from Mars is trapped martian atmospheric gases in the meteorites -- the ultimate fingerprint. Interestingly, we may have a better shot at recognizing a meteorite from Venus, since the Venusian atmosphere has been geochemically and isotopically measured by NASA missions and spectroscopically from Earth. For example, trapped Venusian atmosphere should have a gigantically large ratio of deuterium to hydrogen. In the meantime, there are other ways to think about parent bodies of achondrites -- identifying their meteoritic precursor material. For example, I recently worked on achondrite-ung NWA 8186 that appears to be the first example of an achondrite that is a very good match for having a CK-chondrite precursor -- in other words, take a CK parent body, igneously melt it, and the product is achondrite-ung NWA 8186. Hey, who said the list was boring? Mike, great discussion topic! Carl Agee * Carl B. Agee Director and Curator, Institute of Meteoritics Professor, Earth and Planetary Sciences MSC03 2050 University of New Mexico Albuquerque NM 87131-1126 Tel: (505) 750-7172 Fax: (505) 277-3577 Email: a...@unm.edu http://meteorite.unm.edu/people/carl_agee/ On Wed, Mar 12, 2014 at 6:29 PM, Galactic Stone Ironworks meteoritem...@gmail.com wrote: Hi Listees, Can someone elaborate on why NWA 7325 and it's possible pairings are selling for $10,000/g in some cases? There is speculation that it originated from Mercury, but that is only speculation at this point. One can speculate anything. Heck, it might be from Alpha Centauri. There are 60 other ungrouped achondrites and some of them have very unusual characteristics. Why is NWA 7325 priced so high above the others? The low-TKW does not explain the price (maybe in small part), given the fact that pairings appear to be surfacing. This is not a criticism of any dealer or dealers. I am just curious how people have arrived at this price. Best regards, MikeG -- - Web - http://www.galactic-stone.com Facebook - http://www.facebook.com/galacticstone Twitter - http://twitter.com/galacticstone Pinterest - http://pinterest.com/galacticstone - __ Visit the Archives at http://www.meteorite-list-archives.com Meteorite-list mailing list Meteorite-list
Re: [meteorite-list] Ungrouped Achondrite Prices (NWA 7325 andothers)
Almost all CKs are type 4-6; all CVs are type 3. The few CK3s seem to be CK3/4 or CK3.8 or so. In fact, the only way to recognize a meteorite as CK at all is if it is sufficiently metamorphosed to have many of the olivines equilibrated. If not, the rock will be classified as a CV. Since many of the CK4s and the few CK3s I looked crushed and fragmental, and that many CKs are shocked (which I showed back in 92), then it seems to me that impacts are the means of transforming a CV3 to a CK. Because CKs are oxidized, they clearly are not being made from reduced CVs like Vigarano, Efremovka and Leoville. Because many of the Bali oxidized subgroup have strong petrofabrics and CKs don't then the CKs are either being made from the Allende oxidized subgroup or from a third, heretofore unsampled, oxidized CV subgroup. Anyway, we recommended dropping the CK designation altogether (i.e., call rocks CV3, CV4, CV5, CV6), although the CK designation is so entrenched by this point, that I doubt that this will happen. So, with this background, you could call it a CV-CK parent body, or simply just a CV parent body. One final point, how many CV or CV-CK parent bodies are there? We don't know tha answer to that question for any chondrite group. There may be only one of some groups represented in our collections, or there may be several. (Nearly half of the H chondrites have the same CRE age of about 7.6 Ma), so these samples were all on the same parent body at that time. Other samples may have been on other H chondrite parent bodies or at distant locations on the same parent body. We don't know. But since asteroids tend to b reak into smaller bodies via a collisional cascade, it may well be that by the time the collision occurred that gave us half of the H chondrites, the original parent H chondrfite asteroid had already been broken into several chunks, only one of which was struck at that time. The same may be true for many kinds of meteorites.) Alan Alan Rubin Institute of Geophysics and Planetary Physics University of California 3845 Slichter Hall 603 Charles Young Dr. E Los Angeles, CA 90095-1567 phone: 310-825-3202 e-mail: aeru...@ucla.edu website: http://cosmochemists.igpp.ucla.edu/Rubin.html - Original Message - From: Carl Agee a...@unm.edu To: Alan Rubin aeru...@ucla.edu Cc: Galactic Stone Ironworks meteoritem...@gmail.com; Meteorite List meteorite-list@meteoritecentral.com Sent: Wednesday, March 12, 2014 9:35 PM Subject: Re: [meteorite-list] Ungrouped Achondrite Prices (NWA 7325 andothers) Alan, Thanks, you just saved me from a savaging by reviewers of my paper still in prep! I guess CK 'precursor' is a safer term than 'parent body'? Or are we calling it the CV-CK parent body? (with the UCLA good housekeeping seal of approval). I'm happy with just melting a CV, I used to do that all the time in the lab, except at very high pressure. Carl * Carl B. Agee Director and Curator, Institute of Meteoritics Professor, Earth and Planetary Sciences MSC03 2050 University of New Mexico Albuquerque NM 87131-1126 Tel: (505) 750-7172 Fax: (505) 277-3577 Email: a...@unm.edu http://meteorite.unm.edu/people/carl_agee/ On Wed, Mar 12, 2014 at 10:26 PM, Alan Rubin aeru...@ucla.edu wrote: Carl mentioned a CK parent body. I doubt that there is such a thing. In a recent paper, the UCLA folks suggested that CKs were just metamorphosed CVs. I wrote a column in Meteorite about that not too long ago as well. If this is correct then a CK parent body would really likely be a CV-CK parent body. Carl's idea then becomes a little more complicated. Either you have to make the achondrite straight from a CV or you have to metamorphose the CV material (perhaps by collisions, perhaps by slow heating via 26Al) to make a CK and then melt that. It seems simpler to skip the CK step. Alan Alan Rubin Institute of Geophysics and Planetary Physics University of California 3845 Slichter Hall 603 Charles Young Dr. E Los Angeles, CA 90095-1567 phone: 310-825-3202 e-mail: aeru...@ucla.edu website: http://cosmochemists.igpp.ucla.edu/Rubin.html - Original Message - From: Carl Agee a...@unm.edu To: Galactic Stone Ironworks meteoritem...@gmail.com Cc: Meteorite List meteorite-list@meteoritecentral.com Sent: Wednesday, March 12, 2014 9:06 PM Subject: Re: [meteorite-list] Ungrouped Achondrite Prices (NWA 7325 andothers) Hi Mike and All: Achondrite-ung one of my favorite things! Also the enigmatic groupings like ACA, LOD, WIN, BRAC, URE, fascinating! From what I have seen and heard about NWA 7325 -- simply amazing. The problem has nothing to do with these wonderful achondrites, the problem is our ignorance of their possible parent bodies. Martian and lunar meteorites are of the highest scientific value, not because they are better meteorites, but because we know enough about their parent bodies to make the meteorite - parent body
Re: [meteorite-list] Types of twinning in chondrites?
The most common type of twinning in chondrules in unmetamorphosed chondrites is found in low-Ca clinopyroxenes. It is polysynthetic twinning -- it looks like the pyroxene grains have narrow stripes. These disappear when temperatures go above 630 C or so and won't be found in orthopyroxene. Alan Alan Rubin Institute of Geophysics and Planetary Physics University of California 3845 Slichter Hall 603 Charles Young Dr. E Los Angeles, CA 90095-1567 phone: 310-825-3202 e-mail: aeru...@ucla.edu website: http://cosmochemists.igpp.ucla.edu/Rubin.html - Original Message - From: Jim Wooddell jim.woodd...@suddenlink.net To: meteorite-list@meteoritecentral.com Sent: Saturday, February 22, 2014 5:52 AM Subject: [meteorite-list] Types of twinning in chondrites? Hi all, I was wondering, for those that are experienced with petrology, what types of crystal twinning to do see the most in OC's? Thanks! Jim -- Jim Wooddell jim.woodd...@suddenlink.net http://pages.suddenlink.net/chondrule/ __ Visit the Archives at http://www.meteorite-list-archives.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list __ Visit the Archives at http://www.meteorite-list-archives.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
Re: [meteorite-list] Re-2: Types of twinning in chondrites?
Okay. As I said and Andy said, we can find polysynthetic twins in low-Ca clinopyroxene in type-2 and type-3 chondrites (those rocks that have not been metamorphosed). We can actually find a few such twins surviving in type-4 OC. We can see such twinning in plagioclase (also sometimes called albite twinning) in type-6 chondrites (OC, EH, EL, CK). One final note: since the low-Ca clinopyroxene with twins forms from quenched protopyroxene, we can also see this in shocked chondrites (even if type 5 or 6), when they have been subjected to high temperature excursions and rapid cooling. The low-Ca pyroxene is heated into the protopyroxene range and then rapidly cooled to form twinned low-Ca clinopyroxene that very much resembles the pyroxene phenocrysts in chondrules in unequilibrated chondrites. Alan Alan Rubin Institute of Geophysics and Planetary Physics University of California 3845 Slichter Hall 603 Charles Young Dr. E Los Angeles, CA 90095-1567 phone: 310-825-3202 e-mail: aeru...@ucla.edu website: http://cosmochemists.igpp.ucla.edu/Rubin.html - Original Message - From: Bernd V. Pauli bernd.pa...@paulinet.de To: Jim Wooddell jim.woodd...@suddenlink.net; Meteorite Central meteorite-list@meteoritecentral.com Sent: Saturday, February 22, 2014 1:39 PM Subject: [meteorite-list] Re-2: Types of twinning in chondrites? My pleasure, Jim! Would it be safe to say if I see polysynthetic twinning, odds are it's low-Ca cpx, ... No, you might also be looking at multiple twinning of plagioclase but in that case you may be pretty sure it is *not* an unmetamorphosed chondrite! Bernd To: jim.woodd...@suddenlink.net meteorite-list@meteoritecentral.com __ Visit the Archives at http://www.meteorite-list-archives.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list __ Visit the Archives at http://www.meteorite-list-archives.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
[meteorite-list] Novato
Novato is approved. Alan Rubin Institute of Geophysics and Planetary Physics University of California 3845 Slichter Hall 603 Charles Young Dr. E Los Angeles, CA 90095-1567 phone: 310-825-3202 e-mail: aeru...@ucla.edu website: http://cosmochemists.igpp.ucla.edu/Rubin.html __ Visit the Archives at http://www.meteorite-list-archives.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
Re: [meteorite-list] Removing carbon coating???
I just lightly polish the C-coated section on a 1-µm lap and then clean it with ethanol. Alan Rubin Institute of Geophysics and Planetary Physics University of California 3845 Slichter Hall 603 Charles Young Dr. E Los Angeles, CA 90095-1567 phone: 310-825-3202 e-mail: aeru...@ucla.edu website: http://cosmochemists.igpp.ucla.edu/Rubin.html - Original Message - From: Jim Wooddell jim.woodd...@suddenlink.net To: meteorite-list@meteoritecentral.com Sent: Thursday, January 23, 2014 9:58 AM Subject: [meteorite-list] Removing carbon coating??? Hi List! I've read methanol is good for removing carbon from thin sections. How about using alcohol? Anyone try this? Thank you! Jim -- Jim Wooddell jim.woodd...@suddenlink.net http://pages.suddenlink.net/chondrule/ __ Visit the Archives at http://www.meteorite-list-archives.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list __ Visit the Archives at http://www.meteorite-list-archives.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
Re: [meteorite-list] Near pure Olivine Meteorite
The question of the dearth of olivine meteorites (asteroidal dunites) has been around for a very long time. Most folks have ascribed this paucity as being due to the brittle nature of olivine meteorites relative to pallasites. Pallasites have relatively long cosmic-ray-exposure ages indicating that they can survive the rigors of interplanetary space for a rather long while. Eucrites have much shorter CRE ages on average. This suggests that if asteroidal dunites are from deep in the mantle, they would be in space about as long as the pallasites and not survive because they are no tougher than eucrites. Alan Alan Rubin Institute of Geophysics and Planetary Physics University of California 3845 Slichter Hall 603 Charles Young Dr. E Los Angeles, CA 90095-1567 phone: 310-825-3202 e-mail: aeru...@ucla.edu website: http://cosmochemists.igpp.ucla.edu/Rubin.html - Original Message - From: Jim Wooddell jim.woodd...@suddenlink.net To: meteorite-list@meteoritecentral.com Sent: Tuesday, January 14, 2014 4:05 PM Subject: [meteorite-list] Near pure Olivine Meteorite So, we find pallasites, we find irons, we find chondrites. And, with the pallasites some are loaded with a lot of olivine. So anyone have any scientific ideas why we don't find near pure olivine meteorites? Or do we?? For the sake of conversation... Jim -- Jim Wooddell jim.woodd...@suddenlink.net http://pages.suddenlink.net/chondrule/ __ Visit the Archives at http://www.meteorite-list-archives.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list __ Visit the Archives at http://www.meteorite-list-archives.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
Re: [meteorite-list] Near pure Olivine Meteorite
Iron meteorites tend to break up in the atmosphere at lower depths than stony meteorites, so I suppose that pallasites would also be better able to survive transit through the Earth's atmosphere than dunites. But I am guessing that very few dunites ever make it to the top of the Earth's atmosphere to begin with. Alan Rubin Institute of Geophysics and Planetary Physics University of California 3845 Slichter Hall 603 Charles Young Dr. E Los Angeles, CA 90095-1567 phone: 310-825-3202 e-mail: aeru...@ucla.edu website: http://cosmochemists.igpp.ucla.edu/Rubin.html - Original Message - From: pshu...@messengersfromthecosmos.com To: Alan Rubin aeru...@ucla.edu; Jim Wooddell jim.woodd...@suddenlink.net; meteorite-list@meteoritecentral.com Sent: Tuesday, January 14, 2014 5:27 PM Subject: RE: [meteorite-list] Near pure Olivine Meteorite Would they also melt or more correctly ablate off material faster and more completely upon entering the earth's atmosphere? Pete Original Message Subject: Re: [meteorite-list] Near pure Olivine Meteorite From: Alan Rubin aeru...@ucla.edu Date: Tue, January 14, 2014 6:54 pm To: Jim Wooddell jim.woodd...@suddenlink.net, meteorite-list@meteoritecentral.com The question of the dearth of olivine meteorites (asteroidal dunites) has been around for a very long time. Most folks have ascribed this paucity as being due to the brittle nature of olivine meteorites relative to pallasites. Pallasites have relatively long cosmic-ray-exposure ages indicating that they can survive the rigors of interplanetary space for a rather long while. Eucrites have much shorter CRE ages on average. This suggests that if asteroidal dunites are from deep in the mantle, they would be in space about as long as the pallasites and not survive because they are no tougher than eucrites. Alan Alan Rubin Institute of Geophysics and Planetary Physics University of California 3845 Slichter Hall 603 Charles Young Dr. E Los Angeles, CA 90095-1567 phone: 310-825-3202 e-mail: aeru...@ucla.edu website: http://cosmochemists.igpp.ucla.edu/Rubin.html - Original Message - From: Jim Wooddell jim.woodd...@suddenlink.net To: meteorite-list@meteoritecentral.com Sent: Tuesday, January 14, 2014 4:05 PM Subject: [meteorite-list] Near pure Olivine Meteorite So, we find pallasites, we find irons, we find chondrites. And, with the pallasites some are loaded with a lot of olivine. So anyone have any scientific ideas why we don't find near pure olivine meteorites? Or do we?? For the sake of conversation... Jim -- Jim Wooddell jim.woodd...@suddenlink.net http://pages.suddenlink.net/chondrule/ __ Visit the Archives at http://www.meteorite-list-archives.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list __ Visit the Archives at http://www.meteorite-list-archives.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list __ Visit the Archives at http://www.meteorite-list-archives.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
[meteorite-list] Grand Opening of UCLA Meteorite Gallery
I would like everyone to know that tomorrow afternoon, Friday Jan. 10, is the formal grand opening of the UCLA Meteorite Gallery, located on the third floor of the Geology Building on the UCLA Campus. The Museum will be open weekdays from 9:00 A.M to 4:00 P.M. and the occasional weekend afternoon. (Hours will be posted on our website: www.meteorites.ucla.edu ) The gallery is free to the public. I invite any meteorite enthusiasts visiting Southern California to come by sometime for a visit. The press release is appended below. Alan Space rocks hit UCLA: California's largest meteorite museum opens on campus (Note to editors and reporters: To attend the invitation-only grand opening of the UCLA Meteorite Gallery on Friday, Jan. 10, at 4 p.m., please contact Stuart Wolpert at swolp...@support.ucla.edu or 310-206-0511.) California's largest collection of meteorites, and the fifth-largest collection in the nation, is on display in the new UCLA Meteorite Gallery, which is free to the public. The museum, located in UCLA's Geology Building (Room 3697) is open weekdays from 9 a.m. to 4 p.m. and on some weekend afternoons; please visit the gallery's website, www.meteorites.ucla.edu, for details. A centerpiece of the museum is a 357-pound iron chunk of an asteroid that crashed into Arizona some 50,000 years ago, creating a mile-wide crater just east of Flagstaff. Visitors are allowed to touch the venerable object, which like most other meteorites and like the Earth itself is 4.5 billion years old, said John Wasson, the gallery's curator and a UCLA professor of geochemistry and chemistry. Meteorites are rocks ejected from asteroids, comets, planets or the moon that have traveled through interplanetary space and landed on the Earth's surface. The vast majority come from asteroids. Our goal is to make this gallery the world's best scientifically oriented meteorite museum, Wasson said. Our collection is by far the largest in California and is a gift to the people of Southern California. The opportunity to learn in scientific detail about meteorites has not been available in California before. The collection houses specimens of nearly 1,500 meteorites that illustrate the scientific processes that were active in the early solar system. About 100 of these - representing a wide variety of meteorite types - are currently on display. These include chondrites, which contain large numbers of tiny rocky spherules known as chondrules. The origin of chondrules remains very much a mystery, Wasson said. It appears they were created from clumps of dust in the solar nebula - the gas and dust cloud that existed before planets and asteroids formed - and were zapped in a way that is still unknown. The gallery's images of primitive chondritic meteorites taken with a scanning electron microscope offer detailed views of chondrules. The museum also features backlit samples of a class of beautiful meteorites called pallasites, which contain silicate minerals mixed with metal. These specimens formed at the interface between the metallic core and the silicate mantle of an asteroid, Wasson said. We have no sample of the core of any of the planets or even a major moon, but many of the iron meteorites are samples of an asteroid's core, and they differ from one another, Wasson said. Wasson, a member of UCLA's faculty since 1964, has devoted his scientific career to studying meteorites. Meteorites are fragments that were, in part, the building blocks of the planets, he said. Many of these are the first rocks that formed anywhere in the solar system. They have information about the earliest history of the solar system that we cannot learn from the Earth itself. One of the gallery's exhibits explains how to correctly identify meteorites. Detailed explanations of the samples are provided in display cases and brochures. Alan Rubin, the associate curator of the gallery and a researcher in UCLA's Department of Earth, Planetary and Space Sciences, is an expert in identifying meteorites. He receives samples every few days from people who believe they have found meteorites. They almost never are real meteorites, he said, adding that less than 1 percent actually come from beyond the Earth. Some of these objects mistaken for meteorites - including ordinary rocks, petrified wood and metal slag - are on display in an exhibit aptly titled meteorwrongs. For many years, we've collected beautiful exhibit specimens of meteorites but kept them locked in inaccessible cabinets, Rubin said. It's great to be able to put them out on display for people to see. UCLA's collection of meteorites has grown to nearly 3,000 specimens under the stewardship of Wasson and Rubin, and is among the most extensive in the world. The UCLA Meteorite Gallery's grand opening will be held at 4 p.m. on Jan. 10 and is invitation-only. The event will honor Arlene and Ted
Re: [meteorite-list] What is more important in classification?
I always want a doubly-polished thin section to do classification of stony meteorites. To determine the petrologic type of a chondrite, it is useful to gauge the degree of recrystallization (best done in transmitted light) and look for the size of plagioclase grains (which can be done in an SEM, BSE mode of an electron microprobe, and in reflected light, since plagioclase is a darker gray than olivine or pyroxene). To assess the degree of weathering, reflected light is most useful. The probe, of course, will give you the olivine, pyroxene, plagioclase, kamacite, etc. compositions. But in general, in order to get a feel for a stony meteorite (in terms of shock, brecciation, recrystallization, abundance of matrix material, etc.), I want to be able to use the probe and see the rock in transmitted and reflected light. I can also then probe interesting features that reveal themselves with the petrographic microscope. I don't worry so much about the fuzzy line between classification and research. Alan Alan Rubin Institute of Geophysics and Planetary Physics University of California 3845 Slichter Hall 603 Charles Young Dr. E Los Angeles, CA 90095-1567 phone: 310-825-3202 e-mail: aeru...@ucla.edu website: http://cosmochemists.igpp.ucla.edu/Rubin.html - Original Message - From: Jim Wooddell jim.woodd...@suddenlink.net To: meteorite-list@meteoritecentral.com Sent: Monday, January 06, 2014 7:57 AM Subject: [meteorite-list] What is more important in classification? Hi all! Just a few general questions... The involves a mount and a thin section. What is more important now-a-days in classification? This mainly revolves some questions I have that I am not sure how to ask...mainly to those that classify. If you have a million dollar Scanning Election Microscope and can probe around and can determine classification from the geochem and BSE images, how important is it to see the transmitted and reflected features in a petrographic microscope? I suppose my thoughts and questions are possibly in reference to new technology vs. old technologymaybe not...but close and really deeper than just yes and no answers. Not that SEM's are new technology...just saying. I was told a while back you can not classify without both. So Why??? Are the SEM's not capable of doing what a petrographic microscope can do? Thanks! Jim -- Jim Wooddell jim.woodd...@suddenlink.net http://pages.suddenlink.net/chondrule/ __ Visit the Archives at http://www.meteorite-list-archives.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list __ Visit the Archives at http://www.meteorite-list-archives.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
[meteorite-list] things to ponder
If the largest enstatite chondrite was ever confiscated it would be an Abee Sieze. Spittle dripping down the chin of a prisoner could be considered a con-drool. If atheists are people who don't believe in God, are achondrites meteorites that don't believe in chondrules? Alan Rubin Institute of Geophysics and Planetary Physics University of California 3845 Slichter Hall 603 Charles Young Dr. E Los Angeles, CA 90095-1567 phone: 310-825-3202 e-mail: aeru...@ucla.edu website: http://cosmochemists.igpp.ucla.edu/Rubin.html __ Visit the Archives at http://www.meteorite-list-archives.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
Re: [meteorite-list] Charles Burney Jr. and the term 'asteroid'
The article concludes that asteroid is the right word for these objects. The term is certainly familiar and entrenched, but it means star-like and is appropriate only to the appearance of these objects in a small telescope. Other terms that have been used frequently are minor planet and planetoid. These may be more accurate, but are certainly not euphonious. And we now have one asteroid, Ceres, that is also a dwarf planet. Vermin of the skies has a nice ring to it, but what would we call the asteroid belt -- zone of sky vermin? I think we're stuck with asteroid, but must not forget that the term also refers to starfish (which are, of course, echinoderms from the class Asteroidea). Alan Rubin Institute of Geophysics and Planetary Physics University of California 3845 Slichter Hall 603 Charles Young Dr. E Los Angeles, CA 90095-1567 phone: 310-825-3202 e-mail: aeru...@ucla.edu website: http://cosmochemists.igpp.ucla.edu/Rubin.html - Original Message - From: karmaka karmaka-meteori...@t-online.de To: met-list meteorite-list@meteoritecentral.com Sent: Wednesday, October 09, 2013 3:31 PM Subject: [meteorite-list] Charles Burney Jr. and the term 'asteroid' Dear list members, this sounds interesting: Greek scholar invented the term asteroid, researcher reveals http://www.lodinews.com/ap/nation/article_3c86d500-3070-11e3-9637-10604b9f0f42.html Best regards Martin Postfach fast voll? Jetzt kostenlos E-Mail Adresse @t-online.de sichern und endlich Platz für tausende Mails haben. http://www.t-online.de/email-kostenlos __ Visit the Archives at http://www.meteorite-list-archives.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list __ Visit the Archives at http://www.meteorite-list-archives.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
Re: [meteorite-list] Novato update
I received a sample of Novato for classification not too long after it fell. I made a thin section, did the microscopy and probe work and classified the stone. This was the first thing that was done. I am not working on any paper about the meteorite. I was asked to cut up the small piece I was sent and then send those pieces to different researchers for the gathering of additional data. I sent those out and now have almost no sample left at UCLA save the original thin section. I was told that eventually the requisite amount would be deposited at UCLA as the type specimen after some additional research was done on the specimen. My only interest at this point is to receive the specimen, log it in to the UCLA collection and inform the NOMCOM that everything is now in order. I'm not holding anything up. Alan Alan Rubin Institute of Geophysics and Planetary Physics University of California 3845 Slichter Hall 603 Charles Young Dr. E Los Angeles, CA 90095-1567 phone: 310-825-3202 e-mail: aeru...@ucla.edu website: http://cosmochemists.igpp.ucla.edu/Rubin.html - Original Message - From: Michael Farmer m...@meteoriteguy.com To: Carl Agee a...@unm.edu Cc: Meteorite-list Meteoritecentral meteorite-list@meteoritecentral.com; Robert Verish bolidecha...@yahoo.com Sent: Tuesday, April 30, 2013 9:58 PM Subject: Re: [meteorite-list] Novato update I seem to think this is a control issue. Someone wants total control over the meteorite. Sad to dominate a meteorite fall. Never seen this type of action before. Submission changes nothing about the science or the papers released later. It is simply the act of registering the meteorite officially. I think they don't want to release the type specimen or else the receiving institution (UCLA) or (NASA) will then possibly release papers outside the control of the Consortium? My two kopeks. Michael Sent from my iPhone On May 1, 2013, at 10:50 AM, Carl Agee a...@unm.edu wrote: I'm having a hard time understanding this problem with Novato. Since when do deposit samples not get analyzed and worked on? Maybe I'm missing something here but the way I do it, is the sample gets ID-ed and classified and then if it merits further research that happens next, in that order. For example, you cannot submit an abstract to LPSC or MetSoc on an unclassified or provisional meteorite. Classification is absolutely the first thing that should happen. Carl Agee -- Carl B. Agee Director and Curator, Institute of Meteoritics Professor, Earth and Planetary Sciences MSC03 2050 University of New Mexico Albuquerque NM 87131-1126 Tel: (505) 750-7172 Fax: (505) 277-3577 Email: a...@unm.edu http://meteorite.unm.edu/people/carl_agee/ On Tue, Apr 30, 2013 at 7:53 PM, Michael Farmer m...@meteoriteguy.com wrote: Yes, hunting costs money, lots and lots of it. Ask me, I'm on the other side of the planet right now and western unions as coming in daily. No credit cards accepted where I am:) But we have responsibilities. Pay to play, including getting the type specimen properly curated. I am in 100% agreement with the noncom on this one. Science must come first. Michael Farmer Sent from my iPhone On May 1, 2013, at 7:38 AM, robert crane rrobb...@msn.com wrote: The problem I have is every one should spend their hard earned money in the field looking for these damn things to ease the people that don't leave their driveway. I'm sorry before u bitch and complain get off your ass and not spend time in Stewart Valley or in Franconia getting DCA crap classified. Work in the field and contribute. Make a contribution to science before u bitch about other people. Hunting ain't free. On Apr 30, 2013, at 5:19 PM, Richard Montgomery rickm...@earthlink.net wrote: One of the stones from this find was lent to the NASA team, with an open mind and naivte perhaps; a situation that definitely shook her by total surprise and dismay, when another finder of another stone offered a perspective. She wasn't pleased to learn that she may never see it again. - Original Message - From: Robert Verish bolidecha...@yahoo.com To: Meteorite-list Meteoritecentral meteorite-list@meteoritecentral.com Sent: Tuesday, April 30, 2013 9:34 AM Subject: Re: [meteorite-list] Novato update Thanks Rob, for clearing the air and getting this thread back on track. And now that the dust has settled, we're back to my original concern: Why do we have to wait for just the name to be approved? Here is the question I am posing to the List, stated another way: If everyone is in agreement with the Jenniskins arrangement, then why can't the Committee credit UCLA for the type specimen and move forward with approving at least the name Novato (if need be, at least provisionally)? I mean, what is the difference whether the type specimen goes first to UCLA, then goes to NASA, or vice-versa? I mean, for goodness sake, it's NASA we're talking about here. Why do we have to wait
Re: [meteorite-list] Novato update
I was informed by Laurence Garvie that they don't deal in promises. They will approve the name only after they are notified that an actual physical specimen of the proper mass is in the possession of a qualified institution. Alan Alan Rubin Institute of Geophysics and Planetary Physics University of California 3845 Slichter Hall 603 Charles Young Dr. E Los Angeles, CA 90095-1567 phone: 310-825-3202 e-mail: aeru...@ucla.edu website: http://cosmochemists.igpp.ucla.edu/Rubin.html - Original Message - From: Matson, Robert D. robert.d.mat...@saic.com To: Robert Verish bolidecha...@yahoo.com; Meteorite-list Meteoritecentral meteorite-list@meteoritecentral.com Sent: Tuesday, April 30, 2013 10:57 AM Subject: Re: [meteorite-list] Novato update Hi Bob, Here is the question I am posing to the List, stated another way: If everyone is in agreement with the Jenniskins arrangement, then why can't the Committee credit UCLA for the type specimen and move forward with approving at least the name Novato (if need be, at least provisionally)? I mean, what is the difference whether the type specimen goes first to UCLA, then goes to NASA, or vice-versa? I don't know the answer. This sounds like a good question for Jeff Grossman. I can certainly ~imagine~ some possible explanations, not the least of which is that I believe some past meteorites have gotten Nomenclature Committee approval on the promise of an adequate type specimen, only to have that promise never fulfilled. In the Novato case, it would appear there is more than enough type specimen distributed between at least two recognized institutions; it's just that the final destination of a fraction of it has not yet occurred. Perhaps more to the point, the actual type specimen mass is not yet known, since it involves the balance of a 29-gram sample -- an unknown portion of which has been used in destructive analysis. Kind of hard for the Committee to vote on a meteorite when they don't know the actual type specimen mass -- even if that mass is almost surely greater than 20 grams. None of this discussion would appear to impact the decision to approve a provision name, however. Best, Rob __ Visit the Archives at http://www.meteorite-list-archives.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list __ Visit the Archives at http://www.meteorite-list-archives.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
Re: [meteorite-list] Novato update
Peter informed me yesterday that some additional research is being done, presumably on the sample that is to be donated to UCLA. If all goes according to plan, then sometime, hopefully within the next few months, we'll have the name approved. Alan Alan Rubin Institute of Geophysics and Planetary Physics University of California 3845 Slichter Hall 603 Charles Young Dr. E Los Angeles, CA 90095-1567 phone: 310-825-3202 e-mail: aeru...@ucla.edu website: http://cosmochemists.igpp.ucla.edu/Rubin.html - Original Message - From: Matson, Robert D. robert.d.mat...@saic.com To: Robert Verish bolidecha...@yahoo.com; Meteorite-list Meteoritecentral meteorite-list@meteoritecentral.com Sent: Tuesday, April 30, 2013 10:57 AM Subject: Re: [meteorite-list] Novato update Hi Bob, Here is the question I am posing to the List, stated another way: If everyone is in agreement with the Jenniskins arrangement, then why can't the Committee credit UCLA for the type specimen and move forward with approving at least the name Novato (if need be, at least provisionally)? I mean, what is the difference whether the type specimen goes first to UCLA, then goes to NASA, or vice-versa? I don't know the answer. This sounds like a good question for Jeff Grossman. I can certainly ~imagine~ some possible explanations, not the least of which is that I believe some past meteorites have gotten Nomenclature Committee approval on the promise of an adequate type specimen, only to have that promise never fulfilled. In the Novato case, it would appear there is more than enough type specimen distributed between at least two recognized institutions; it's just that the final destination of a fraction of it has not yet occurred. Perhaps more to the point, the actual type specimen mass is not yet known, since it involves the balance of a 29-gram sample -- an unknown portion of which has been used in destructive analysis. Kind of hard for the Committee to vote on a meteorite when they don't know the actual type specimen mass -- even if that mass is almost surely greater than 20 grams. None of this discussion would appear to impact the decision to approve a provision name, however. Best, Rob __ Visit the Archives at http://www.meteorite-list-archives.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list __ Visit the Archives at http://www.meteorite-list-archives.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
Re: [meteorite-list] I've been a miner for a heart of ....
As long as we're being serious, Jeff has zeroed in on the most valuable property of asteroids -- water. Until and unless manufacturing occurs off the Earth, it is unlikely that PGE mining of asteroids will be cost-effective. But as humans again start exploring space beyond low Earth orbit, water will be a highly valuable commodity. Capturing carbonaceous asteroids that contain 8-12 wt.% water will enable manned missions, where to some extent, astronauts could live off the land like old-time invading armies. If we could also learn to eat asteroids and use them for fuel, that would be a great energy savings -- much less mass would have to be lifted off the Earth. Alan Alan Rubin Institute of Geophysics and Planetary Physics University of California 3845 Slichter Hall 603 Charles Young Dr. E Los Angeles, CA 90095-1567 phone: 310-825-3202 e-mail: aeru...@ucla.edu website: http://cosmochemists.igpp.ucla.edu/Rubin.html - Original Message - From: Kevin Kichinka mars...@gmail.com To: meteorite-list@meteoritecentral.com Sent: Sunday, April 07, 2013 2:35 PM Subject: [meteorite-list] I've been a miner for a heart of platinum (with apologies to Neil Young). Team Meteorite: This 'string' regarding 'asteroid mining' has attracted the scholarly attention of the Rubin's and Grossman's and seems worth tying into a couple more knots. I'm all thumbs though when tying knots, so subject to peer review which I will cheerfully accept from my uber peers Rubin and Grossman (as well as my everyday peers on this forum). . here's some more facts and data dug from two mining company websites, hopefully properly interpreted by me, the mini-peer :) On Earth, typically ten tons of ore must be crushed and refined to yield one oz of platinum or platinum group metals (pgm). *** That fact informs me that an unsupervised process in a harsh environment like found on an asteroid in space will have a lower yield. The main concept of all this discussion is that bulk rock has to be processed for shipping in a small package. Next up is an abridged description of the process of mining ore to acquire platinum group metals(pgm), compiled/copied from two websites of mining companies in Africa, probably the richest source of Earth's pgm. *Concentration The ore is ground to liberate mineral particles. These are then recovered in the form of a concentrate by froth flotation. The ore mineralogy dictates both the fineness of grind required for liberation and the ideal flotation conditions. Very fine particles are difficult to recover, so two or even three milling and flotation stages may be used to minimise losses caused by over-grinding. There are minor differences in the details of the equipment and operations employed processing a metallic concentrate rich in PGMs is sometimes produced in addition to the flotation concentrate. This concentrate can be sufficiently rich to by-pass the smelter and be sent straight to base metal removal. *Smelting The concentrate is melted in an electric furnace. Large units with six electrodes in line are used for smelting concentrates.Upon melting, the concentrate separates into two layers. The upper layer is a silicate/oxide slag which is tapped off and then either discarded or returned to concentration. The lower layer is a sulphide motto which is sent for converting. The flotation-concentrate composition must be suitable for smelting. Its rock mineral content should produce a fluid slag at the desired temperature. At the same time, it must contain enough sulphides to form a reasonable quantity of matter. To compensate for minor problems with chemical composition, various fluxes are added. Typically, the main addition is burnt lime or limestone but other materials such as carbonaceous reductants, sulphides, oxides or silicates are used as necessary. *Base metal removal Base metals are removed from the converter matte either by leaching or by a combination of magnetic separation and leaching processes. Problem elements such as selenium, arsenic and tellurium are also removed. The concentrate which results is sent for further processing into refined precious metals. Base metals are a valuable by-product of PGM extraction. Their further refining by the various producers is largely dictated by economies of scale. Refining Precious metals refining processes have developed considerably in recent years. The older or ’classical’ process involved first roasting the PGM concentrate. This made the rhodium, iridium and ruthenium insoluble in aqua regia. The platinum, palladium and gold were then dissolved and separated by a series of sequential precipitations, The remaining residue was then upgraded by pyro-metallurgical and leaching processes before being separated into individual metals. Final purification of all metals
Re: [meteorite-list] Sign Up Now for your Mineral Rights (Mining Asteroids for Platinum)
According to coolquiz.com, the commercial value of the substances in the average human body is $4.50. The average adult man has a mass of about 80 kg; the average adult woman, about 60 kg. So, the average adult person is about 70 kg. This indicates that the average adult is worth about $64/MT, nearly two-thirds the commercial value of a chondrite according to Jeff's calculation. I'm sure that there are philosophical implications to this, but I'm tired and can't figure them out. Alan Alan Rubin Institute of Geophysics and Planetary Physics University of California 3845 Slichter Hall 603 Charles Young Dr. E Los Angeles, CA 90095-1567 phone: 310-825-3202 e-mail: aeru...@ucla.edu website: http://cosmochemists.igpp.ucla.edu/Rubin.html - Original Message - From: Jeff Grossman jngross...@gmail.com To: meteorite-list@meteoritecentral.com Sent: Saturday, April 06, 2013 6:24 PM Subject: Re: [meteorite-list] Sign Up Now for your Mineral Rights (Mining Asteroids for Platinum) I just did my own calculation... at pure metal prices, I find most chondrites are worth around $100/metric ton, with Pt dominating the calculation. Of the major groups of carbonaceous, ordinary, and enstatite chondrites, H chondrites are worth the most... I get $162/ton ($80 of which is Pt, $25 Pd, $24 Ir, $12 Au, $10 Os, $8 Rh, $3 Ru). I would put our 15-m radius C-type asteroid at around $1.5M worth of precious metals. Can somebody else reproduce $15B, which is 1 x what I got? I used the following prices in $/kg: $2,733RU $38,585RH $23,441PD $868AG $3,500RE $12,219OS $32,154IR $49,486PT $50,836AU H chondrites have the following concentrations in kg/ton (which is the same as mg/g) RU0.00111 RH0.000207 PD0.0011 AG0.841 RE0.8 OS0.00082 IR0.00074 PT0.0016 AU0.00023 And our 15-m radius C asteroid with density=1 g/cc weighs 14000 metric tons. So Pt in this asteroid is 49486 $/kg * 0.0016 Kg/ton * 14000 tons = $1,100,000 Did I mess something up? I'm tired, so maybe I did something wrong. If you use an iron meteorite, you can multiply by 5. Jeff On 4/6/2013 5:47 PM, Michael Mulgrew wrote: Not to worry, executives from De Beers are forming a corporation to take care of just that. Michael in so. Cal. On Sat, Apr 6, 2013 at 6:47 AM, Michael Farmer m...@meteoriteguy.com wrote: The problem is that supply and demand must equalize. I would think that the arrival of more platinum that has ever been mined would instantly depress the price on the open market. Michael Farmer Sent from my iPhone On Apr 6, 2013, at 12:56 AM, bill kies parkforest...@hotmail.com wrote: All in due time. It will be mind numbing to the nth degree when profits are made. The potential for fees and regulation are as limitless as the greed based hallucinations that currently strip us of our ability, our will, to produce on an entrepreneurial level no matter how basic. From: mikest...@gmail.com Date: Fri, 5 Apr 2013 21:23:19 -0700 To: mars...@gmail.com CC: meteorite-list@meteoritecentral.com Subject: Re: [meteorite-list] Sign Up Now for your Mineral Rights (Mining Asteroids for Platinum) Just wait until you see the BLM permitting process to establish a mining claim on an asteroid... Michael is so. Cal. On Fri, Apr 5, 2013 at 8:25 PM, Kevin Kichinka mars...@gmail.com wrote: Team Meteorite: When Ron Baalke forwarded today a news article about mining asteroids for platinum, I at once thought of science-fiction movies I have seen from behind a box of artificially-buttered popcorn. You know, those flicks where slaves from Earth work 84 year-days far beneath the surface of some bare rock-moon in space partnered with creatures normally viewed among the protozoa. Of course there is no possible escape from this living death, but movies need happy endings so our heroes always make it home to their Honey. Mining asteroids seems a bit far-fetched to me. But ask a question or make a comment on the m-list and someone opens the door to knowledge for you. Just walk through. Thanks to Randy Korotev, I know that OC's may contain Pt at ore-grade concentrates of 1ppm. But really, how concentrated is that I wondered, ever the sceptic. Two seconds research informed me that Platinum is an extremely rare metal, occurring at a concentration of only 0.005 ppm in the Earth's crust. Looking deeper into the topic (research is like mining, just keep digging and you'll always find your bone) ... Platinum exists in higher abundances on the Moon and in meteorites. Correspondingly, platinum is found in slightly higher abundances at sites of bolide impact on the Earth that are associated with resulting post-impact volcanism, and can be mined economically; the Sudbury Basin is one such example. And... From 1889 to 1960, the meter was defined as the length of a platinum-iridium (90:10) alloy bar, known
Re: [meteorite-list] Origin of chondrules
I'll be happy to give my opinion on the paper. I think it is completely wrong. Here is my reasoning: 1. Many chondrules are surrounded by secondary igneous shells, still others by igneous rims. These shells and rims indicate that the chondrules haev experienced more than one melting event. 2. Many FeO-rich (i.e., Type-II) porphyritic olivine chondrules contain relict grains of different FeO contents and different O-isotopic compositions, again indicating multiple melting. This is very hard in a collision model. 3. One might expect molten planetesimals to have well-mixed melts. If the chondrules are mainly from the larger planetesimal (the target) as one would expect, the O isotopic compositions of the chondrules would probably be mass-fractionated and lie on a slope-1/2 line on the standard three-isotope diagram. We don't see this. 4. One might also expect that as the planestimal melted and began to crystallize, it would become chemically fractionated, unlike the unfractionated, solar, compositions of chondrules in primitive chondrites. 5. The occurrence of microchondrules in the fine-grained rims around some normal-size chondrules and the apparent melting of pyroxene at the outer surface of the chondrule to form the microchondrules indicates chondrule melting by a mechanism capable of melting only the outer surface of the chondrule. This is totally inconsistent with the formation by splashing by the collision of molten planetesimals. 6. There are correlations between chondrule size, the proportion of different chondrule types, the proportion of those with igneous rims and secondary shells that are difficult to explain by splashing but come naturally to a model invoking multiple melting in dusty nebular regions. 7. The non-spherical shapes of most CO chondrules indicates very rapid cooling or else they would have collapsed into spheres. This might be okay except for the fact that the large size of their phenocrysts require a growth period thousands of times longer than the time it would take a molten droplet to collapse into a sphere. This again indicates a flash heating mechanism. 8. The fairly rare occurrence of chondrule-CAI mixtures are difficult to explain by colliding molten planetesimals, but are sinple to explain by melting of a mafic dustball that had and old CAI fragment inside. 9. Each chondrite group has its own distinctive narrow range of chondrule sizes. In fact, about 90% of the chondrules in any group have diameters within a factor of 2 of the mean size. One would expect molten planetesimals to produce a similar size of chondrules range for each group. Furthermore, chondrule size is correlated with lots of other chondrule properties (proportions of textural types, numbers with rims and secondary shells, etc.) that are hard to explain by molten planetesimals. 10. And, I just don't see how we get the different chondrule textural types by that model. Some chondrules lack olivine, others lack pyroxene, some are coarse grained, some are fine-grained, some have a mixture of different size grains, some include relict grains. This seems impossible to produce by the molten planetesimal model. Since I only have 10 fingers, I'll stop there. Alan Rubin Institute of Geophysics and Planetary Physics University of California 3845 Slichter Hall 603 Charles Young Dr. E Los Angeles, CA 90095-1567 phone: 310-825-3202 e-mail: aeru...@ucla.edu website: http://cosmochemists.igpp.ucla.edu/Rubin.html - Original Message - From: Mendy Ouzillou ouzil...@yahoo.com To: met-list meteorite-list@meteoritecentral.com Sent: Tuesday, March 12, 2013 7:06 PM Subject: [meteorite-list] Origin of chondrules And now for something completely different ... Meteorite talk. I am in the process of reading through a fascinating article in latest issue of Meteoritics and Planetary Science called The Origin of Chondrules and Chondrites: Debris from Low Velocity Impacts Between Molten Planetisimals. This paper is very well written and readable even by a novice such as myself. What I find interesting is the proposal for a (somewhat) new theory that chondrules did not instantly form from clumps of heated nebular dust but instead formed 1.5 to 2.5MY after the formation of CAIs. the paper states that chondrules formed from splashing when two differentiated planetisimals collided at a relatively slow speed of between 10 to 100m/s. Without being able to review the previous papers, I have to say that to me this makes a great deal of sense and appears to solve many of the inconsistencies that have been raised in some of the older books that I have read. Note: there is a typo in the paer on page 2177. Is states A strength of the splashing model is that it can explain why chondrules are mostly between 1.5 and 2.5MYr younger than CAI The sentence should read older, no younger. Dr. Jeff Grossman, would love to hear your thoughts on this paper. Mendy
Re: [meteorite-list] Origin of chondrules
Let me re-emphasize this point. None of us know anything for sure. We may look at the same data and view it differently, place more importance on some constraints than others, and place higher value on our own research than that of our colleagues. If the work is good, it will tend to be credited, provisionally accepted and possibly improved upon. If the workers in the field think that a paper is wrong-headed, they will either critize it formally or ignore it. Over time, we are hopefully lurching toward a better understanding. I've reviewed papers that I thought came to the wrong conclusions, but since the work was cogent, I recommended acceptance. In one recent case (Greenwood's claim that CK chondrites were nothing more than metamorphosed CV chondrites), I later came to realize that I had been wrong and the paper's conclusions were correct. So, it is important to let a thousand flowers bloom. Alan Alan Rubin Institute of Geophysics and Planetary Physics University of California 3845 Slichter Hall 603 Charles Young Dr. E Los Angeles, CA 90095-1567 phone: 310-825-3202 e-mail: aeru...@ucla.edu website: http://cosmochemists.igpp.ucla.edu/Rubin.html - Original Message - From: Galactic Stone Ironworks meteoritem...@gmail.com To: Mendy Ouzillou ouzil...@yahoo.com Cc: Peter Scherff petersche...@rcn.com; Meteorite List meteorite-list@meteoritecentral.com Sent: Wednesday, March 13, 2013 8:29 AM Subject: Re: [meteorite-list] Origin of chondrules Hi Mendy, Peter, and List, Science is fluid affair and nobody agrees 100% on anything. The origin of chondrules, whatever that process that might actually be, is theorized based on the evidence we see today. That evidence is partial and we are only seeing a tiny part of the creation process. From that evidence, we postulate and theorize. But, nobody was alive to witness the creation of chondrules, so lacking first-hand direct evidence, we have to make observations via the scientific method. I don't know the authors of the paper in question. I have not read the paper in question. But, suffice to say, MAPS is not the Journal of Cosmology. If the paper appeared there, then it must have some merit or value. The peers are that reviewed the paper (whoever they are) are surely qualified to determine whether or not the authors of the paper have followed the scientific method properly. They observed, they tested, they authored, they published. It is up to the scientific community to embrace or deny the results, by replicating those results independently. If the authors followed the correct protocols in conducting their research, then their theory (even if wrong) can add positively to the body of knowledge, even if most of the other scientists disagree with the theory. Think of these journals as like bulletin boards for scientific theory. Scientists put their work out their on the board to announce something to the world and their peers. The bulletin board can be crowded and filled with contradictory messages. The rest of the scientific community can pick and choose between the things on the bulletin board. Over time, the erroneous or misguided work is pushed aside and the work with merit is forwarded by the scientific method. What makes meteoritics exciting for the layman, in comparison to many other fields that are less-accessible, is that we (the laymen) have direct access to the same scientists who publish many of these papers. There aren't too many fields where you can read a paper, post questions to a mailing list, and get authoritative answers from some of the best minds in the field. I won't even name them, for fear of leaving someone out, but we have the brightest minds in meteoritics lurking on this list and they often take time out of their work to educate us nagging laymen. That is exciting to me. :) Best regards, MikeG -- - Web - http://www.galactic-stone.com Facebook - http://www.facebook.com/galacticstone Twitter - http://twitter.com/GalacticStone Pinterest - http://pinterest.com/galacticstone RSS - http://www.galactic-stone.com/rss/126516 - On 3/13/13, Mendy Ouzillou ouzil...@yahoo.com wrote: Peter, No one disputes science is messy, but Jim's point is valid. Drs. Rubin and Grossman have forgotten more than I will likely know in regards to meteoritics, but I also feel a bit frustrated. I expect papers in a journal like Meteoritics and Planetary Science to be thoroughly reviewed before being published. It's not an issue of a few esoteric differences, it's about the paper as a whole being rejected by esteemed and respected meteoriticists. Again, Jim's question is valid. Was this paper peer reviewed? I'm sure it was, which leads to the next question. How was it allowed to be published if it is so far off? The answer is important to me because I do not have the time to read
Re: [meteorite-list] Type 7 chondrites
Most classifiers don't use the type-7 designation because many of the chondrites that have been called type-7 seem to be impact-melt breccias. Most researchers believe that thermal metamorphism probably caused by asteroidal heating engendered by the decvay of short-lived radionuclides like 26-Al heated chondrites from type 3 to 4 to 5 to 6. If shock was responsible for causing a rock to be called type 7, then it seemed more prudent to just call it shocked and not use the type-7 designation. Most researchers believe that the primitive achondrites were also partly (or completely) melted by heating caused by the decay of 26-Al. I am not of these camps; it seems to me that heating of chondrites from type 3 to type 6 also results from impact heating and that the primitive achondrites formed in an analogous way, but that is another story. Alan Alan Rubin Institute of Geophysics and Planetary Physics University of California 3845 Slichter Hall 603 Charles Young Dr. E Los Angeles, CA 90095-1567 phone: 310-825-3202 e-mail: aeru...@ucla.edu website: http://cosmochemists.igpp.ucla.edu/Rubin.html - Original Message - From: Peter Scherff petersche...@rcn.com To: 'Adam' meteorite-list@meteoritecentral.com Sent: Monday, March 04, 2013 3:14 PM Subject: [meteorite-list] Type 7 chondrites Hi, Is there any consensus about petrologic type 7 chondrites? Are they better classified as Primitive Achondrites? If type 7 is different from primitive achondtites what is the line between them? Thanks, Peter Scherff __ Visit the Archives at http://www.meteorite-list-archives.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list __ Visit the Archives at http://www.meteorite-list-archives.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
Re: [meteorite-list] Type 7 chondrites
The designations of petrologic type is based on texture (pristine or recrystallized) and degree of mineralogical equilibration. Those that appear most recrystallized have rather uniform mineral compositions indicative of a high degree of annealing or thermal metamorphism. Although other properties also vary with petrologic type (e.g., the concentration of some volatile elements), those other properties are not the main classificatory criteria. The petrologic types are the phenomenon that requires us to think of a heat source. In the past, some maintained that chondrites accreted hot from the nebula and were autometamorphosed. Few believe that these days. As I said before, most researchers attribute the apparent annealing to the decay of 26-Al, which was undoubtedly present. My papers over the past 20 years have provided evidence that impact-heating was a major heat source for chondi\ritic meteorites. Both mechanisms may have been active. As far as achondrites are concerned, their designation is based on having a chondrule-free, usually igneous, texture. They appear to have formed from a melt. The particular isotopic compositions of different achondrite groups (e.g., HEDs, aubrites, angrites) are not important for distinguishing chondrites from achondrites. But we are again faced with the question of what heat source or sources caused achondrites to melt. Most researchers would maintain that it was mainly 26-Al. Alan Rubin Institute of Geophysics and Planetary Physics University of California 3845 Slichter Hall 603 Charles Young Dr. E Los Angeles, CA 90095-1567 phone: 310-825-3202 e-mail: aeru...@ucla.edu website: http://cosmochemists.igpp.ucla.edu/Rubin.html - Original Message - From: Mendy Ouzillou ouzil...@yahoo.com To: Richard Montgomery rickm...@earthlink.net; Alan Rubin aeru...@ucla.edu; Peter Scherff petersche...@rcn.com; 'Adam' meteorite-list@meteoritecentral.com Sent: Monday, March 04, 2013 5:35 PM Subject: Re: [meteorite-list] Type 7 chondrites Dr. Rubin, If I read your response carefully, I believe you are saying that the petrologic state should not depend on the type of metamorphic process which makes sense. Seems to me that the the isotopic analysis should be used to identify chondritic material from achondritic material. Mendy Ouzillou - Original Message - From: Richard Montgomery rickm...@earthlink.net To: Alan Rubin aeru...@ucla.edu; Peter Scherff petersche...@rcn.com; 'Adam' meteorite-list@meteoritecentral.com Cc: Sent: Monday, March 4, 2013 5:14 PM Subject: Re: [meteorite-list] Type 7 chondrites What thoughts about Taffessasset in this regard? Anyone wish to chime in? Richard M - Original Message - From: Alan Rubin aeru...@ucla.edu To: Peter Scherff petersche...@rcn.com; 'Adam' meteorite-list@meteoritecentral.com Sent: Monday, March 04, 2013 3:41 PM Subject: Re: [meteorite-list] Type 7 chondrites Most classifiers don't use the type-7 designation because many of the chondrites that have been called type-7 seem to be impact-melt breccias. Most researchers believe that thermal metamorphism probably caused by asteroidal heating engendered by the decvay of short-lived radionuclides like 26-Al heated chondrites from type 3 to 4 to 5 to 6. If shock was responsible for causing a rock to be called type 7, then it seemed more prudent to just call it shocked and not use the type-7 designation. Most researchers believe that the primitive achondrites were also partly (or completely) melted by heating caused by the decay of 26-Al. I am not of these camps; it seems to me that heating of chondrites from type 3 to type 6 also results from impact heating and that the primitive achondrites formed in an analogous way, but that is another story. Alan Alan Rubin Institute of Geophysics and Planetary Physics University of California 3845 Slichter Hall 603 Charles Young Dr. E Los Angeles, CA 90095-1567 phone: 310-825-3202 e-mail: aeru...@ucla.edu website: http://cosmochemists.igpp.ucla.edu/Rubin.html - Original Message - From: Peter Scherff petersche...@rcn.com To: 'Adam' meteorite-list@meteoritecentral.com Sent: Monday, March 04, 2013 3:14 PM Subject: [meteorite-list] Type 7 chondrites Hi, Is there any consensus about petrologic type 7 chondrites? Are they better classified as Primitive Achondrites? If type 7 is different from primitive achondtites what is the line between them? Thanks, Peter Scherff __ Visit the Archives at http://www.meteorite-list-archives.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list __ Visit the Archives at http://www.meteorite-list-archives.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
Re: [meteorite-list] Met Bulletin Update - EL's and OC's
If specimens are part of an observed fall and are very fresh looking, one supposes (without absolute certainty) that the different individuals are paired. If stones are found lying on the ground in an area that has yielded few other meteorites, then one can also assume that they are paired, but the certainty is lower. The probability can increase, however, if they are of a rare type. But if stones are found in a region where there are overlapping strewnfields or if some concentration mechanism has brought different meteorites together, then we are less certain that they are paired even if they are of an unusual type. We may say that they are probably paired (particularly if they have similar textures, bulk compositions, terrestrial ages, cosmic-ray expsosure ages, etc.), but the prudent thing to do (since we generally don't have all of these data) is to treat them as separate meteorites with separate numbers and let the pairing be a scientifically derived conclusion, not a curatorial assignment. Alan Rubin Institute of Geophysics and Planetary Physics University of California 3845 Slichter Hall 603 Charles Young Dr. E Los Angeles, CA 90095-1567 phone: 310-825-3202 e-mail: aeru...@ucla.edu website: http://cosmochemists.igpp.ucla.edu/Rubin.html - Original Message - From: Mendy Ouzillou ouzil...@yahoo.com To: 'Robert Verish' bolidecha...@yahoo.com; 'Jeff Grossman' jngross...@gmail.com; meteorite-list@meteoritecentral.com Sent: Sunday, February 17, 2013 3:13 PM Subject: Re: [meteorite-list] Met Bulletin Update - EL's and OC's Bob, Sorry it took me so long to respond - the email got buried under a Russian meteorite. Your explanation is logical, but the classifiers did not mention these two stones as being paired. Seeing as these were very likely found close to each other (but perhaps subjected to different weathering conditions) they should at a minimum be stated as paired. I know it is impossible to prevent the explosion of numbers assigned for the reasons you stated below - I get that, but at what point does it become too burdensome (rhetorical question)? How do scientists know what numbers are paired together if the two classifications do not state it that way (not rhetorical)? Best, Mendy -Original Message- From: Robert Verish [mailto:bolidecha...@yahoo.com] Sent: Sunday, February 17, 2013 1:02 AM To: 'Jeff Grossman'; meteorite-list@meteoritecentral.com; Mendy Ouzillou Subject: Re: [meteorite-list] Met Bulletin Update - EL's and OC's One benefit of having two numbers is that it allows the classifier to clarify the differences between the two stones in order to show the range of variation among these paired EL stones. The difference in this case being one stone has Alabandite present, and the second stone was Extremely weathered showing only rare metal. Rare alabandite. This would actually aid a subsequent classifier of another EL6 stone to be able to pair that third stone to the other two. Otherwise that subsequent classifier (not being aware of this variation) may be misled into thinking that the third stone is unpaired. When I first read Mendy's question about assignment of NWA numbers, I thought he was making reference to assignment of provisional numbers. These are usually assigned before the stones are classified and if the stones have any appearance of outwardly looking different to each other, the prudent requester is wise to get a number for each stone. Once a requester gets two numbers assigned, it's not likely that a classifier will get rid of one number. Where is the motivation if the classifier will get more type-specimen by having each stone numbered. If the classifier submits a classification for each numbered stone, the NomCom will accommodate that classifier by approving both numbers. Anything less, and the NomCom would be considered unaccommodating. Now, in defense of the classifier for not getting rid of one of the numbers, I would say that the test lies in answering this question: What is the added-value in discarding a number? (Which is basically what Jeff Grossman was saying when he asked, Why is this a problem?) Or stated another way: Is there any added-value in approving two numbers that were assigned to two stones that were subsequently paired? For one answer to that question as it relates to these two EL6 stones, go to the beginning of this post. Bob V. --- On Sat, 2/16/13, Mendy Ouzillou ouzil...@yahoo.com wrote: From: Mendy Ouzillou ouzil...@yahoo.com Subject: Re: [meteorite-list] Met Bulletin Update - EL's and OC's To: 'Jeff Grossman' jngross...@gmail.com, meteorite-list@meteoritecentral.com Date: Saturday, February 16, 2013, 8:51 PM Because as I read it the data for both specimens are the same within the margin of error and the two specimens should share one number. M -Original Message- From: meteorite-list-boun...@meteoritecentral.com [mailto:meteorite-list-boun...@meteoritecentral.com] On Behalf Of Jeff
Re: [meteorite-list] Nwa 7034
The bottom line in all of this is that meteorite group names will last only as long as they're useful. The literature of the past is littered with group names such as grahamites and others I've forgotten because they fell out of use. Similarly, the term SNC is not used much these days although the individual group names survive. If scientisits no longer find it useful to use the term shergottite, then it will gradually fall out of use. If folks invent new names and no one uses them, then it doesn't really matter. An interesting analogy is that there are some unpopular models for chondrule formation, for example, (say gamma-ray bursts) that no one uses and thus don't pollute the literature. Alan Alan Rubin Institute of Geophysics and Planetary Physics University of California 3845 Slichter Hall 603 Charles Young Dr. E Los Angeles, CA 90095-1567 phone: 310-825-3202 e-mail: aeru...@ucla.edu website: http://cosmochemists.igpp.ucla.edu/Rubin.html - Original Message - From: Carl Agee a...@unm.edu To: meteoritelist meteoritelist meteorite-list@meteoritecentral.com Sent: Sunday, January 27, 2013 8:20 AM Subject: Re: [meteorite-list] Nwa 7034 Hi Jeff, Of course the comparison between chondrite groups and martian types is not perfect. The different martian types are not from different parent bodies, but we still don't know where they come from on Mars, and won't for a long time, not until we know the geology of Mars better. So for a large body like a planet, and given our fragmentary knowledge of Mars, different regions are more or less equivalent to different parent bodies. Describing martians with generic lithologic names that were developed for Earth geology is useful, but for example we don't hesitate to use the term mid-ocean ridge basalts (MORB) for Earth's most abundant rock type, which will never be found on Mars. The same is true for Mars because of a different planetary evolution. We are already doing this based on rover data, the term Gusev basalt is one example. SNC's plus ALH 84001 and NWA 7034 are, each type, glimpses of diversity of Mars' unique geology. Carl Agee -- Carl B. Agee Director and Curator, Institute of Meteoritics Professor, Earth and Planetary Sciences MSC03 2050 University of New Mexico Albuquerque NM 87131-1126 Tel: (505) 750-7172 Fax: (505) 277-3577 Email: a...@unm.edu http://meteorite.unm.edu/people/carl_agee/ -- Forwarded message -- From: Jeff Grossman jngross...@gmail.com To: meteorite-list@meteoritecentral.com Cc: Date: Sun, 27 Jan 2013 00:06:22 -0500 Subject: Re: [meteorite-list] Nwa 7034 There are two reasons why we can't get rid of carbonaceous chondrite group names. First, unlike Martian meteorites, we don't know where C chondrites came from. We can't point to a single asteroid as the source for any of them, let alone all of them. So the group names are still serving their basic purpose of ordering the chaos. Second, the only language we have to describe the rocks known as chondrites is by their group names. They can't be described with standard rock nomenclature. So this is not a fair comparison. I didn't say Martian meteorite names were not useful. I said they were archaic, historical artifacts. Jeff On 1/26/2013 11:38 PM, Carl Agee wrote: Hi Jeff and all you Nomenclature Enthusiasts out there: I think the martian meteorite names do serve a useful purpose, they are a sort of short-hand, so that you don’t have to be an igneous petrologist to know that one type of martian is different from another. So when we say a martian meteorite is a “NWA7034-ite”, or “blackbeauty-ite”, or a “saharite” or whatever name you want to pick, we are implicitly talking about a breccia, that is water-rich, alkali basalt, with higher-than-SNC oxygen isotope values, ~ 2 byo, etc. For example, like it or not, when we say “Allan Hills” the first thing comes that comes to mind is ALH 84001. When you say orthopyroxenite maybe not so much. If it’s such a great idea to do away with martian types, why don’t we go ahead and do away with all the carbonaceous chondrite groups like CI, CM, CV, etc. and just call them all carbonaceous chondrites, that of course have a wide range of compositions, textures, mineralogies etc.? Meteoritics isn’t the only science that has colorful nomenclature. Mineralogists still like to name new minerals after famous mineralogists, instead of just naming them by their chemical composition or crystal structure. Carl Agee __ Visit the Archives at http://www.meteorite-list-archives.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list __ Visit the Archives at http://www.meteorite-list-archives.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo
Re: [meteorite-list] Smallest Meteorite
As Jeff Grossman uncovered, the smallest object named byu the NMomenclature Committee is Y 8333 which weighs 12 mg. It corresponds to a particle about 2 mm in diameter. Alan Rubin Institute of Geophysics and Planetary Physics University of California 3845 Slichter Hall 603 Charles Young Dr. E Los Angeles, CA 90095-1567 phone: 310-825-3202 e-mail: aeru...@ucla.edu website: http://cosmochemists.igpp.ucla.edu/Rubin.html - Original Message - From: Anne Black impact...@aol.com To: meteorite-list@meteoritecentral.com Sent: Wednesday, December 05, 2012 3:49 PM Subject: [meteorite-list] Smallest Meteorite Hello, This question came up on another forum. What is the smallest meteorite known? And I mean: still recognizable (classifiable) as a meteorite. And no, I am not talking about the highly questionable micrometeorites supposedly found in gutters. I am sure one of you will know the answer!! Thanks. Anne M. Black www.IMPACTIKA.com impact...@aol.com __ Visit the Archives at http://www.meteorite-list-archives.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list __ Visit the Archives at http://www.meteorite-list-archives.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
Re: [meteorite-list] SF Chronicle - Dismissed 'rock' a meteorite after all
I just read the article in the Chronicle and send this e-mail to the writer: David: I just read your article and have a correction to make. I understand that it is easy to confuse unfamiliar terms, and it probably makes no difference to the vast majority of your readers. However, what I said was that chondrules are igneous objects that solidified from molten spherules in the solar nebula. Chondrites are rocks that contain the chondrules. Chondrites are not igneous rocks. Igneous rocks have been melted; chondrites have not. If the chondrites had been melted, the chondrules inside of them would have been melted also and would have disappeared. For meteorite researchers this is a fundamental point. Chondrites are unmelted, agglomerated rocks that preserve inclusions from the earliest history of the solar system. These inclusions include the chondrules. Alan Alan Rubin Institute of Geophysics and Planetary Physics University of California 3845 Slichter Hall 603 Charles Young Dr. E Los Angeles, CA 90095-1567 phone: 310-825-3202 e-mail: aeru...@ucla.edu website: http://cosmochemists.igpp.ucla.edu/Rubin.html - Original Message - From: Jim Wooddell jimwoodd...@gmail.com To: meteorite-list@meteoritecentral.com Sent: Friday, October 26, 2012 6:56 AM Subject: Re: [meteorite-list] SF Chronicle - Dismissed 'rock' a meteorite after all Maybe they ought to name it Isnotis :) Jim On Fri, Oct 26, 2012 at 6:47 AM, Brien Cook cont...@briencook.com wrote: http://www.sfgate.com/science/article/Dismissed-rock-a-meteorite-after-all-3982409.php ___ Unlimited Disk, Data Transfer, PHP/MySQL Domain Hosting http://www.doteasy.com __ Visit the Archives at http://www.meteoritecentral.com/mailing-list-archives.html Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list -- Jim Wooddell jimwoodd...@gmail.com 928-247-2675 __ Visit the Archives at http://www.meteoritecentral.com/mailing-list-archives.html Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list __ Visit the Archives at http://www.meteoritecentral.com/mailing-list-archives.html Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
Re: [meteorite-list] Lisa Webber's is a meteorite
Most meteorite petrographers have a lot of experience looking at meteorite whole rocks, not just thin sections. Over the years, I can usually tell a meteorite from a wrong, but when I am not sure, I make a thin section before making an announcement. What I am not so good at is guessing what kind of a meteorite it is before I see a thin section. Jason Utas, for example, is much better at that than I am. Alan Rubin Institute of Geophysics and Planetary Physics University of California 3845 Slichter Hall 603 Charles Young Dr. E Los Angeles, CA 90095-1567 phone: 310-825-3202 e-mail: aeru...@ucla.edu website: http://cosmochemists.igpp.ucla.edu/Rubin.html - Original Message - From: dorifry dori...@embarqmail.com To: Michael Mulgrew mikest...@gmail.com; Michael Farmer m...@meteoriteguy.com Cc: meteorite-list@meteoritecentral.com Sent: Thursday, October 25, 2012 9:40 AM Subject: Re: [meteorite-list] Lisa Webber's is a meteorite Michael, A lot of times scientists used to working in labs with thin slices can't tell an ordinary chondrite from a hole in the ground. They often specialize in a narrow academic field and have no experience handling all different types of meteorites. It's hard to beat years of hands on experience when it comes to field grading meteorites. Plus, these stones have highly unusual crust. I didn't think they were meteorites because of the weird crust, but it's hard to tell just from looking at an out of focus photograph. Phil Whitmer Joshua Tree Earth Space Museum - Original Message - From: Michael Mulgrew mikest...@gmail.com To: Michael Farmer m...@meteoriteguy.com Cc: meteorite-list@meteoritecentral.com; Brien Cook cont...@briencook.com Sent: Thursday, October 25, 2012 12:31 PM Subject: Re: [meteorite-list] Lisa Webber's is a meteorite Am I to understand that one of NASA's best has problems identifying a meteorite? Is anyone else concerned by that? Michael in So. Cal. On Thu, Oct 25, 2012 at 6:45 AM, Michael Farmer m...@meteoriteguy.com wrote: Of course it is. Sadly the damage is done. I am in Germany and all I am seeing is news reports now calling it a meteor wrong. What a cluster#+~. Michael Farmer Sent from my iPhone On Oct 25, 2012, at 3:39 PM, Brien Cook cont...@briencook.com wrote: http://cams.seti.org/ ___ Unlimited Disk, Data Transfer, PHP/MySQL Domain Hosting http://www.doteasy.com __ Visit the Archives at http://www.meteoritecentral.com/mailing-list-archives.html Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list __ Visit the Archives at http://www.meteoritecentral.com/mailing-list-archives.html Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list __ Visit the Archives at http://www.meteoritecentral.com/mailing-list-archives.html Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list __ Visit the Archives at http://www.meteoritecentral.com/mailing-list-archives.html Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list __ Visit the Archives at http://www.meteoritecentral.com/mailing-list-archives.html Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
Re: [meteorite-list] Sutter's Mill slices question, Impact Melt?
A few CK6s have impact-melt zones within them, but I haven't seen any such zones in a CM. Alan Rubin Institute of Geophysics and Planetary Physics University of California 3845 Slichter Hall 603 Charles Young Dr. E Los Angeles, CA 90095-1567 phone: 310-825-3202 e-mail: aeru...@ucla.edu website: http://cosmochemists.igpp.ucla.edu/Rubin.html - Original Message - From: meteorh...@aol.com To: Meteorite-list@meteoritecentral.com Sent: Thursday, May 17, 2012 9:57 AM Subject: [meteorite-list] Sutter's Mill slices question, Impact Melt? Hey List, I just got in some slices of Sutter's Mill. So I have a question, do carbonaceous chondrites ever have impact melt zones in them? Steve Arnold Host of Meteorite Men Sent from my Verizon Wireless BlackBerry __ Visit the Archives at http://www.meteoritecentral.com/mailing-list-archives.html Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list __ Visit the Archives at http://www.meteoritecentral.com/mailing-list-archives.html Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
Re: [meteorite-list] Asteroid Or Comet Sutters Mill
I guess I've been goaded into responding. First, at this point we don't know if the meteorite is a CM chondrite or not. No meteorite researcher has completed an analysis of it yet (perhaps tomorrow or Friday) and I have not seen a piece. But, on the more general question of CM chondrites, most researchers believe that the carbonaceous chondrites all are derived from asteroids. There is more or less a continuum in properties across the chondrite groups; it is difficult to imagine that they are from different classes of parent bodies, i.e., asteroids vs. comets. All chondrite groups (except CI) contain chondrules, CAIs, matrix, metal and sulfide although the abundances of these phases can vary a lot among the groups. Even CI chondrites contain a few olivine and pyroxene grains that seem to be chondrule fragments, a few refractory mineral grains that seem to be CAI fragments, and even one reported intact CAI. Furthermore, the isolated olivine and pyroxene grains in CI chondrites have the same olivine Fa vs. CaO distribution as in CM chondrites suggesting that they are from a similar source. I think that the CM chondrites are from an asteroid that was fairly porous and had a fair amount of water, present either as ice or in phyllosilicates. Stochastic impacts on this asteroid caused fracturing in some regions more than others and during subsequent aqueous alteration (probably caused by impact mobilization of water), the more fractured regions retained more water and became more altered. Alan Rubin Institute of Geophysics and Planetary Physics University of California 3845 Slichter Hall 603 Charles Young Dr. E Los Angeles, CA 90095-1567 phone: 310-825-3202 e-mail: aeru...@ucla.edu website: http://cosmochemists.igpp.ucla.edu/Rubin.html - Original Message - From: Matson, Robert D. robert.d.mat...@saic.com To: meteorite-list meteorite-list@meteoritecentral.com Sent: Wednesday, May 02, 2012 2:16 PM Subject: Re: [meteorite-list] Asteroid Or Comet Sutters Mill Hi Paul, Probably not a misquote -- Dr. Jenniskens is interested in deciphering the nature of the original asteroid (meteoroid) body that produced the meteorites. The original body was large enough that it may not have been a monolithic body; as with 2008 TC3 (Almahata Sitta), the pre-encounter body may have been a rubble pile, consisting of more than just CM2 material. In any case, I don't think the parent body (or bodies) for CM2 is cometary. Would be interested in hearing Dr. Rubin's theory on the nature of the CM2 parent. --Rob -Original Message- From: meteorite-list-boun...@meteoritecentral.com [mailto:meteorite-list-boun...@meteoritecentral.com] On Behalf Of Paul Gessler Sent: Wednesday, May 02, 2012 2:08 PM To: meteorite-list Subject: [meteorite-list] Asteroid Or Comet Sutters Mill In the LA times article it reads in part: We want to learn about this asteroid, said Peter Jenniskens, an astronomer and senior research scientist at the Carl Sagan Center at the SETI (Search for Extraterrestrial Intelligence) Institute and the NASA Lunar Science Institute. This is scientific gold. I hope/probably they miss quoted him? I vote comet Paul G __ Visit the Archives at http://www.meteoritecentral.com/mailing-list-archives.html Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list __ Visit the Archives at http://www.meteoritecentral.com/mailing-list-archives.html Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
Re: [meteorite-list] Primitive Achondrite Question
I thought I would add my tuppance worth. I don't use the type-7 classification. If a chondrite shows no evidence of melting, I'll classify it as type-6 no matter how recrystallized it may be -- whether there are recognizable chondrules or not. If the rock does show evidence of melt, there are invariably indications that the melt has been impact-generated and I'll call the rock an impact-melt breccia. If the rock has been essentially totally melted, I'll call it an impact-melt rock. Almost all of these rocks can be assigned to a known chondrite group on the basis of olivine Fa, O isotopes, bulk chemistry, etc. If a rock is a winonaite or acapulcoite, it can be classified as such. But if we want to understand how these primitive achondrite groups formed (not required for classification purposes), there are basically two schools of thought. Most researchers maintain that primitive achondrites are rocks that have been partly melted by internal heating processes (ala Al-26) and the heating and fractionation just did not proceed as far as in the case of true achondrites. A minority of researchers (including me) believe it is more likely that primitive achondrites are impact-melted chondrites and are thus not that different than chondrite impact-melt breccias and chondrite impact-melt rocks. As I said earlier, the origin of these meteorites is not important for their proper classification, but it can lead to heated debates. Alan Alan Rubin Institute of Geophysics and Planetary Physics University of California 3845 Slichter Hall 603 Charles Young Dr. E Los Angeles, CA 90095-1567 phone: 310-825-3202 e-mail: aeru...@ucla.edu website: http://cosmochemists.igpp.ucla.edu/Rubin.html - Original Message - From: MexicoDoug mexicod...@aim.com To: raremeteori...@yahoo.com; meteorite-list@meteoritecentral.com Sent: Tuesday, December 06, 2011 9:31 AM Subject: Re: [meteorite-list] Primitive Achondrite Question Adam wrote: NWA 3133 is a CV Primitive Achondrite Hi Adam, thanks ... The asteroid belt ought to be called the asteroid zoo! The question I have on this one, if CV is for certain, would be whether it is the result of a collision with a typical CV type, or is it certain that it is a fully baked CV (what happened to the possible CAI's - are there any, or is the CV possibly just impact regolith?), or, whether some innocent CV got hot all by itself. Kinest wishes Doug (Why does my wallet retract down my pocket every time ths stuff comes up!) -Original Message- From: Adam Hupe raremeteori...@yahoo.com To: Adam meteorite-list@meteoritecentral.com Sent: Tue, Dec 6, 2011 11:47 am Subject: Re: [meteorite-list] Primitive Achondrite Question Doug wrote: I can't wait until someone turns up a CV6+. Theoretically, there is no reason to bar the possibility,, or is there... NWA 3133 is a CV Primitive Achondrite All of these oxygen isotope compositions plot on the CV3 mixing line, suggesting that this achondritic meteorite has affinities with CV chondrites (Irving et al., 2004). __ Visit the Archives at http://www.meteoritecentral.com/mailing-list-archives.html Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list __ Visit the Archives at http://www.meteoritecentral.com/mailing-list-archives.html Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list __ Visit the Archives at http://www.meteoritecentral.com/mailing-list-archives.html Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
Re: [meteorite-list] Primitive Achondrite Question
Classifications are just a way of making sense of the world by putting diverse objects into tidy categories. Even though real-world objects don't always fit (is light a wave or a particle?), good classifications last longer than interpretations. For example, the Linnaeus classification system was developed from a creationist perspective but is used today by every evolutionary biologist. So, to answer your question, classification is an end in itself -- it certainly helps in understanding relationships among diverse objects. But classification is not the only end -- understanding the origins of objects is also rather important, but because we have incomplete knowledge of objects, our interpretations are always tentative, subject to revision when new data are acquired. Classifications should be longer-lasting. As an aside, if you are interested in bad classification systems for meteorites, look at George Merrill's The Story of Meteorites from 1929: There are andrites, eukrites, shergottites, howardites, bustites, chassignites, chladnites, amphoterites, howarditic chondrites, white chondrites, intermediate chondrites, gray chondrites, black chondrites, spherulitic chondrites, crystalline chondrites, carbonaceous chondrites, orvinites, tadjerites, ureilites, lodranies, grahamite mesosiderites, siderophyrs, and more. Some of the groups are still recogniable, others less so. The problem was that the knowledge base at the time was insufficient to distinguish essential from secondary properties. Similar problems arose among classification schemes of living creatures and especially fossils. Alan Alan Rubin Institute of Geophysics and Planetary Physics University of California 3845 Slichter Hall 603 Charles Young Dr. E Los Angeles, CA 90095-1567 phone: 310-825-3202 e-mail: aeru...@ucla.edu website: http://cosmochemists.igpp.ucla.edu/Rubin.html - Original Message - From: MexicoDoug mexicod...@aim.com To: raremeteori...@yahoo.com; meteorite-list@meteoritecentral.com Sent: Tuesday, December 06, 2011 9:31 AM Subject: Re: [meteorite-list] Primitive Achondrite Question Adam wrote: NWA 3133 is a CV Primitive Achondrite Hi Adam, thanks ... The asteroid belt ought to be called the asteroid zoo! The question I have on this one, if CV is for certain, would be whether it is the result of a collision with a typical CV type, or is it certain that it is a fully baked CV (what happened to the possible CAI's - are there any, or is the CV possibly just impact regolith?), or, whether some innocent CV got hot all by itself. Kinest wishes Doug (Why does my wallet retract down my pocket every time ths stuff comes up!) -Original Message- From: Adam Hupe raremeteori...@yahoo.com To: Adam meteorite-list@meteoritecentral.com Sent: Tue, Dec 6, 2011 11:47 am Subject: Re: [meteorite-list] Primitive Achondrite Question Doug wrote: I can't wait until someone turns up a CV6+. Theoretically, there is no reason to bar the possibility,, or is there... NWA 3133 is a CV Primitive Achondrite All of these oxygen isotope compositions plot on the CV3 mixing line, suggesting that this achondritic meteorite has affinities with CV chondrites (Irving et al., 2004). __ Visit the Archives at http://www.meteoritecentral.com/mailing-list-archives.html Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list __ Visit the Archives at http://www.meteoritecentral.com/mailing-list-archives.html Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list __ Visit the Archives at http://www.meteoritecentral.com/mailing-list-archives.html Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
Re: [meteorite-list] Primitive Achondrite Question
It seems that the primary classification of iron meteorites is best done by compositon, i.e., comparing the Ga-Ge, Ir-Ni, Cu-As ratios etc. of different irons on diagrams and look for relationships. This is what gives rise to the IAB, IVA, IIIAB groups etc. Most groups are called magmatic because their trends on such diagrams are consistent with fractional crystallization inside a molten core. A few groups (IAB-IIICD and IIE) are called non-magmatic because their trends are inconsistent with fractional crystallization. Some researchers believe that all of these irons (magmatic and non-magmatic alike) are derived from the cores of differentiated asteroids or from large melt pods inside melted asteroids. Other researchers (particularly John Wasson) think that the non-magmatic irons are impact melts formed at the surfaces of chondritic bodies. I agree with Wasson. Many of the non-magmatic irons have silicate inclusions that are roughly chondritic in bulk composition and contain planetary-type rare gases as do chondrites. In any case, the structures of irons (coarse octahedrite, ataxite, hexahedrite) are secondary properties influenced by cooling rate and nucleation; the primary properties are the bulk chemical and isotopic compositions of the irons. Alan Alan Rubin Institute of Geophysics and Planetary Physics University of California 3845 Slichter Hall 603 Charles Young Dr. E Los Angeles, CA 90095-1567 phone: 310-825-3202 e-mail: aeru...@ucla.edu website: http://cosmochemists.igpp.ucla.edu/Rubin.html - Original Message - From: cdtuc...@cox.net To: raremeteori...@yahoo.com; Alan Rubin aeru...@ucla.edu; meteorite-list@meteoritecentral.com Sent: Tuesday, December 06, 2011 1:07 PM Subject: Re: [meteorite-list] Primitive Achondrite Question Alan, I agree with Darryl. Very fascinating conversation. Speaking of tidy categories. How do you feel about the following suggested case for replacing the current obsolete metallurgy system for classifying Iron meteorites? see link; http://meteormetals.com/Case_for_New_Meteorite_Metallurgy.pdf Cheers, Carl meteoritemax Alan Rubin aeru...@ucla.edu wrote: Classifications are just a way of making sense of the world by putting diverse objects into tidy categories. Even though real-world objects don't always fit (is light a wave or a particle?), good classifications last longer than interpretations. For example, the Linnaeus classification system was developed from a creationist perspective but is used today by every evolutionary biologist. So, to answer your question, classification is an end in itself -- it certainly helps in understanding relationships among diverse objects. But classification is not the only end -- understanding the origins of objects is also rather important, but because we have incomplete knowledge of objects, our interpretations are always tentative, subject to revision when new data are acquired. Classifications should be longer-lasting. As an aside, if you are interested in bad classification systems for meteorites, look at George Merrill's The Story of Meteorites from 1929: There are andrites, eukrites, shergottites, howardites, bustites, chassignites, chladnites, amphoterites, howarditic chondrites, white chondrites, intermediate chondrites, gray chondrites, black chondrites, spherulitic chondrites, crystalline chondrites, carbonaceous chondrites, orvinites, tadjerites, ureilites, lodranies, grahamite mesosiderites, siderophyrs, and more. Some of the groups are still recogniable, others less so. The problem was that the knowledge base at the time was insufficient to distinguish essential from secondary properties. Similar problems arose among classification schemes of living creatures and especially fossils. Alan Alan Rubin Institute of Geophysics and Planetary Physics University of California 3845 Slichter Hall 603 Charles Young Dr. E Los Angeles, CA 90095-1567 phone: 310-825-3202 e-mail: aeru...@ucla.edu website: http://cosmochemists.igpp.ucla.edu/Rubin.html - Original Message - From: MexicoDoug mexicod...@aim.com To: raremeteori...@yahoo.com; meteorite-list@meteoritecentral.com Sent: Tuesday, December 06, 2011 9:31 AM Subject: Re: [meteorite-list] Primitive Achondrite Question Adam wrote: NWA 3133 is a CV Primitive Achondrite Hi Adam, thanks ... The asteroid belt ought to be called the asteroid zoo! The question I have on this one, if CV is for certain, would be whether it is the result of a collision with a typical CV type, or is it certain that it is a fully baked CV (what happened to the possible CAI's - are there any, or is the CV possibly just impact regolith?), or, whether some innocent CV got hot all by itself. Kinest wishes Doug (Why does my wallet retract down my pocket every time ths stuff comes up!) -Original Message- From: Adam Hupe raremeteori...@yahoo.com To: Adam meteorite-list
Re: [meteorite-list] NWA 6694 / Abee
Many of the clasts in Abee have metal-rich rims. These rims surrounded the clasts during the last impact-melting event wherein the matrix was melted and the clasts generally survived and helped to quench the melt. In many of these metal rims, there are euhedral grains of enstatite that crystallized from the matrix melt. Alan Rubin Institute of Geophysics and Planetary Physics University of California 3845 Slichter Hall 603 Charles Young Dr. E Los Angeles, CA 90095-1567 phone: 310-825-3202 e-mail: aeru...@ucla.edu website: http://cosmochemists.igpp.ucla.edu/Rubin.html - Original Message - From: Larry Atkins thetop...@aol.com To: fcre...@prodigy.net; meteorite-list@meteoritecentral.com Sent: Friday, September 16, 2011 6:12 AM Subject: Re: [meteorite-list] NWA 6694 / Abee Hi Frank, List, i see the shadows but that's not what I'm talking about. If you lookk at the individual chunks and pieces in the Abee you will notice that many of them appear to have a lighter 'rim' around them, follow me? Now that I've looked at other pictures of different specimens, I'm thinkning it may have to do with metal shine but I'm not sure. I'm wondering what might cause this appearance of a rim around the individual pieces that make up the meteorite. Thanks. Sincerely, Larry Atkins IMCA # 1941 Ebay alienrockfarm -Original Message- From: Frank Cressy fcre...@prodigy.net To: Larry Atkins thetop...@aol.com Cc: meteoritelist meteorite-list@meteoritecentral.com Sent: Wed, Sep 14, 2011 11:40 pm Subject: Re: [meteorite-list] NWA 6694 / Abee Hi Larry all, I think the weathering effects on the Abee are shadows on the large slice. Notice that they're different in each image. Frank - Original Message From: Larry Atkins thetop...@aol.com To: meteorite-list@meteoritecentral.com Sent: Wed, September 14, 2011 8:17:35 PM Subject: [meteorite-list] NWA 6694 / Abee Hello List, Several list members brought it to my attention that the last 3 images in Edwin's photo album are of Abee, not NWA 6694. My mistake. I should've figured it out when I noticed the 'weathering' effect was not evident in the first images of the hand specimen, '6694, only the last 3 images of the big slab of Abee. I didn't see any comments on this weathering effect seen in clasts of the Abee, can anyone explain what's going on there? Having not ever seen a piece of it in person it's hard to tell exactly what I'm looking at. Now that I know it's an EH chondrite I'm wondering if the high metal is somehow causing the effect. Thanks! Sincerely, Larry Atkins IMCA # 1941 Ebay alienrockfarm __ Visit the Archives at http://www.meteoritecentral.com/mailing-list-archives.html Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list __ Visit the Archives at http://www.meteoritecentral.com/mailing-list-archives.html Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list __ Visit the Archives at http://www.meteoritecentral.com/mailing-list-archives.html Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
Re: [meteorite-list] Scientists Find New Type Of Mineral In Historic Meteorite (Wassonite - Yamato 691)
It is indeed the small amount of free oxygen that creates the conditions for some of the minerals unique to enstatite meteorites to form. These include a lot of sulfides that would be unstable on Earth. Minerals like oldhamite (CaS) are highly unstable in the presence of water. Wassonite (TiS) would not likely occur on the Earth. Alan Rubin Institute of Geophysics and Planetary Physics University of California 3845 Slichter Hall 603 Charles Young Dr. E Los Angeles, CA 90095-1567 phone: 310-825-3202 e-mail: aeru...@ucla.edu website: http://cosmochemists.igpp.ucla.edu/Rubin.html - Original Message - From: Thunder Stone stanleygr...@hotmail.com To: baa...@zagami.jpl.nasa.gov; meteorite-list@meteoritecentral.com Sent: Tuesday, April 05, 2011 1:51 PM Subject: Re: [meteorite-list] Scientists Find New Type Of Mineral In Historic Meteorite (Wassonite - Yamato 691) List: I have always wondered why there are minerals found on meteorites (asteroids) and not on earth (terrestrial) rocks. Is it the less gravity? Is it the lack of Oxygen? Or some other factors. Really interesting stuff. Greg S. From: baa...@zagami.jpl.nasa.gov To: meteorite-list@meteoritecentral.com Date: Tue, 5 Apr 2011 12:17:34 -0700 Subject: [meteorite-list] Scientists Find New Type Of Mineral In Historic Meteorite (Wassonite - Yamato 691) April 5, 2011 Dwayne C. Brown Headquarters, Washington 202-358-1726 dwayne.c.br...@nasa.gov William Jeffs Johnson Space Center, Houston 281-483-5111 william.p.je...@nasa.gov RELEASE: 11-098 SCIENTISTS FIND NEW TYPE OF MINERAL IN HISTORIC METEORITE HOUSTON -- NASA and co-researchers from the United States, South Korea and Japan have found a new mineral named Wassonite in one of the most historically significant meteorites recovered in Antarctica in December 1969. The new mineral was discovered within the meteorite officially designated Yamato 691 enstatite chondrite. The meteorite was discovered the same year as other landmark meteorites Allende and Murchison and the return of the first Apollo lunar samples. The study of meteorites helps define our understanding of the formation and history of the solar system. The meteorite likely may have originated from an asteroid orbiting between Mars and Jupiter. Wassonite is among the tiniest, yet most important, minerals identified in the 4.5-billion-year-old sample. The research team, headed by NASA space scientist Keiko Nakamura-Messenger, added the mineral to the list of 4,500 officially approved by the International Mineralogical Association. Wassonite is a mineral formed from only two elements, sulfur and titanium, yet it possesses a unique crystal structure that has not been previously observed in nature, said Nakamura-Messenger. In 1969, members of the Japanese Antarctic Research Expedition discovered nine meteorites on the blue ice field of the Yamato Mountains in Antarctica. This was the first significant recovery of Antarctic meteorites and represented samples of several different types. As a result, the United States and Japan conducted systematic follow-up searches for meteorites in Antarctica that recovered more than 40,000 specimens, including extremely rare Martian and lunar meteorites. Researchers found Wassonite surrounded by additional unknown minerals that are being investigated. The mineral is less than one-hundredth the width of a human hair or 50x450 nanometers. It would have been impossible to discover without NASA's transmission electron microscope, which is capable of isolating the Wassonite grains and determining their chemical composition and atomic structure. More secrets of the universe can be revealed from these specimens using 21st century nano-technology, said Nakamura-Messenger. The new mineral's name was approved by the International Mineralogical Association. It honors John T. Wasson, professor at the University of California, Los Angeles (UCLA). Wasson is known for his achievements across a broad swath of meteorite and impact research, including the use of neutron activation data to classify meteorites and to formulate models for the chemical makeup of bulk chondrites. Meteorites, and the minerals within them, are windows to the formation of our solar system, said Lindsay Keller, space scientist at NASA's Johnson Space Center in Houston. Keller is the co-discoverer and principal investigator of the microscope used to analyze the Wassonite crystals. Through these kinds of studies we can learn about the conditions that existed and the processes that were occurring then. Johnson's advanced work in nanotechnology is part of the center's Astromaterial Research and Exploration Science Directorate. It is currently the location for celestial materials that would be returned to Earth from spacecraft. The facility collaborates with industry, academic and international organizations. The beauty of this research is that it really demonstrates how the Johnson
[meteorite-list] iron meteorite cooling rates and Meteorite Men
On last night's Meteorite Men show, the narrator was attempting to explain that the Widmanstatten pattern is caused by kamacite and taenite cooling at different rates. This is incorrect. How could two intergrown metal grains buried deep inside a core cool at different rates? The Widmanstatten pattern forms in the following manner: (1) At high temperatures (but below the solidus), metallic Fe-Ni exists as a single phase -- taenite. (2) As the metal cools, it eventually reaches the two-phase field (or solvus) on the phase diagram. For metal containing 90% iron and 10% nickel, it reaches this boundary when temperatures cool to about 700ºC. (3) At this point, small kamacite grains nucleate inside the taenite. With continued cooling, the kamacite grains grow larger at the expense of taenite, but both phases become richer in nickel. This is possible because the low-Ni phase (kamacite) is becoming increasingly abundant. (4) At low temperatures, say 400ºC or so, diffusion becomes so sluggish that the reaction essentially stops. These meteorites are called octohedrites because solids have three-dimensional structures and the kamacite planes are oriented with respect to each other in the same way as the faces of a regular octahedron. Alan Rubin Institute of Geophysics and Planetary Physics University of California 3845 Slichter Hall 603 Charles Young Dr. E Los Angeles, CA 90095-1567 phone: 310-825-3202 e-mail: aeru...@ucla.edu website: http://cosmochemists.igpp.ucla.edu/Rubin.html __ Visit the Archives at http://www.meteoritecentral.com/mailing-list-archives.html Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
Re: [meteorite-list] iron meteorite cooling rates and Meteorite Men
The iron meteorite cooling rates generally range from about 1 - 100ºC/Myr. The reason for such slow rates is that the metal cores are buried deeply within silicate mantles and heat cannot readily escape. The coarseness of the Widmanstatten pattern is a function of cooling rate -- more slowly cooled irons will develop thicker kamacite lamellae. But there are two other factors that govern the coarseness of the structure -- the Ni concentration and the nucleation temperature. The lower the Ni concentration in the metal, the more kamacite will develop upon cooling. Metal that begins to nucleate at a higher temperature will have a longer period within which kamacite can grow. Alan Rubin Institute of Geophysics and Planetary Physics University of California 3845 Slichter Hall 603 Charles Young Dr. E Los Angeles, CA 90095-1567 phone: 310-825-3202 e-mail: aeru...@ucla.edu website: http://cosmochemists.igpp.ucla.edu/Rubin.html __ Visit the Archives at http://www.meteoritecentral.com/mailing-list-archives.html Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
Re: [meteorite-list] iron meteorite cooling rates and Meteorite Men
Magmatic iron meteorites (including the large IIIAB group) are thought to have formed by fractional crystallization within the cores of differentiated asteroids, layered by silicate mantles. Asteroidal collisions can eventually expose the cores (which in many or most cases have already crystallized) and send some of the pieces on their way to the inner solar system. Nonmagmatic irons (such as IAB) are more controversial. Some think that they also formed in cores; others that they formed as metal melt pools at the bottoms of impact craters on chondritic asteroids. Alan Rubin Institute of Geophysics and Planetary Physics University of California 3845 Slichter Hall 603 Charles Young Dr. E Los Angeles, CA 90095-1567 phone: 310-825-3202 e-mail: aeru...@ucla.edu website: http://cosmochemists.igpp.ucla.edu/Rubin.html - Original Message - From: Richard Montgomery rickm...@earthlink.net To: Alan Rubin aeru...@ucla.edu; meteorite-list@meteoritecentral.com Sent: Wednesday, December 15, 2010 4:47 PM Subject: Re: [meteorite-list] iron meteorite cooling rates and Meteorite Men Hi List. (ot a chemist, me, just a collector, not ametorologist, just a passionate meteorite guy. This is mostly a question from Allan's post just now: I was always under the impression that iron meteorites resulted from colliding differentiated parent-bodies, and that the crystallization sequence was achieved after an impact that exposed a core, molten NiFe suddenly ejected into space without the shield of its former silicate mantle. Am I way off base? Does Thompson structure develope within? - Original Message - From: Alan Rubin aeru...@ucla.edu To: meteorite-list@meteoritecentral.com Sent: Wednesday, December 15, 2010 4:21 PM Subject: Re: [meteorite-list] iron meteorite cooling rates and Meteorite Men The iron meteorite cooling rates generally range from about 1 - 100ºC/Myr. The reason for such slow rates is that the metal cores are buried deeply within silicate mantles and heat cannot readily escape. The coarseness of the Widmanstatten pattern is a function of cooling rate -- more slowly cooled irons will develop thicker kamacite lamellae. But there are two other factors that govern the coarseness of the structure -- the Ni concentration and the nucleation temperature. The lower the Ni concentration in the metal, the more kamacite will develop upon cooling. Metal that begins to nucleate at a higher temperature will have a longer period within which kamacite can grow. Alan Rubin Institute of Geophysics and Planetary Physics University of California 3845 Slichter Hall 603 Charles Young Dr. E Los Angeles, CA 90095-1567 phone: 310-825-3202 e-mail: aeru...@ucla.edu website: http://cosmochemists.igpp.ucla.edu/Rubin.html __ Visit the Archives at http://www.meteoritecentral.com/mailing-list-archives.html Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list __ Visit the Archives at http://www.meteoritecentral.com/mailing-list-archives.html Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
Re: [meteorite-list] Any irons/stony-irons linked to known stones?
Most folks believe that the chondrites are from undifferentiated, unmelted asteroids. Hence, they would not be expected to have iron cores. That said, those researchers who believe that asteroids are heated internally (the majority), by the decay of short-lived radionuclides like Al-26, aver that the interiors of asteroids are highly metamorphosed. Some might suggest that the deep interiors were partially melted. If asteroids were heated mainly be collisions (a minority viewpoint that I share), then the interiors wouldn't be expected to be appreciably hotter than the surfaces and the asteroids would remain undifferentiated. Alan Rubin Institute of Geophysics and Planetary Physics University of California 405 Hilgard Avenue Los Angeles, CA 90095-1567 phone: 310-825-3202 e-mail: aeru...@ucla.edu website: http://cosmochemists.igpp.ucla.edu/Rubin.html - Original Message - From: Melanie Matthews miss_meteor...@yahoo.ca To: Jeff Kuyken i...@meteorites.com.au; bar...@univ-brest.fr Cc: Meteorite List meteorite-list@meteoritecentral.com Sent: Tuesday, August 31, 2010 9:13 AM Subject: Re: [meteorite-list] Any irons/stony-irons linked to known stones? Is it theorized that the parent asteroids of ordinary and carbonaceous chondrites, might be differentiated with iron cores? --- -Melanie IMCA: 2975 eBay: metmel2775 Known on SkyRock Cafe as SpaceCollector09 I eat, sleep and breath meteorites 24/7. - Original Message From: Jeff Kuyken i...@meteorites.com.au To: bar...@univ-brest.fr; Melanie Matthews miss_meteor...@yahoo.ca Cc: Meteorite List meteorite-list@meteoritecentral.com Sent: Tue, August 31, 2010 4:54:07 AM Subject: Re: [meteorite-list] Any irons/stony-irons linked to known stones? I've been reading up recently on various parent-bodies etc and there are a bunch of theories out there regarding various irons and stones. One that I can think of off the top of my head is that some consider the Horse Creek iron to have a potential origin in common with the Aubrites and/or Enstatite Chondrites. Cheers, Jeff - Original Message - From: bar...@univ-brest.fr To: Melanie Matthews miss_meteor...@yahoo.ca Cc: Meteorite List meteorite-list@meteoritecentral.com Sent: Tuesday, August 31, 2010 4:37 PM Subject: Re: [meteorite-list] Any irons/stony-irons linked to known stones? Hi, at present, excepted winonaites with IAB irons, no known group of iron is connected to a group of achondrite. The situation is slightly different for mesosiderites and pallasites. The silicate portion of the mesosiderites is certainly linked to HEDs but the metal and the silicates are not genetically linked. Concerning pallasites, they have been considered to be linked with IIIAB irons, but that's really unlikely (see the recent paper in PSRD by Scott...). Again, it is unlikely that the large impact basin in Vesta displays the core of the body... cheers Jean-Alix Selon Melanie Matthews miss_meteor...@yahoo.ca: Are any chondrites and/or achondrites suspected as originating from the same parent body as any known irons and stony-irons? Someone mentioned something asking about the possibility of some irons coming from 4 Vesta in another thread, not too long ago... Cheers --- -Melanie IMCA: 2975 eBay: metmel2775 Known on SkyRock Cafe as SpaceCollector09 I eat, sleep and breath meteorites 24/7. __ Visit the Archives at http://www.meteoritecentral.com/mailing-list-archives.html Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list __ Visit the Archives at http://www.meteoritecentral.com/mailing-list-archives.html Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list __ Visit the Archives at http://www.meteoritecentral.com/mailing-list-archives.html Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list __ Visit the Archives at http://www.meteoritecentral.com/mailing-list-archives.html Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
Re: [meteorite-list] Nickel free metal in Meteorites
Low-Ni or Ni-free iron doesn't occur just in some chondrules. It is also found in impact-melt-rock clasts in ordinary chondrites and at the edges of olivine grains in ureilites. These rocks have experienced localized in situ reduction of FeO to metallic Fe as Jeff has pointed out. But let's look at the context, these low-Ni metallic iron grains are situated within mafic silicate grains that have lots of SiO2, MgO and (away from the reduced metal) FeO. They are formed in the solid state. A large iron meteorite isn't situated within a mass of mafic silicate. You could argue that it broke off, but this also wouldn't work. Diffusion of oxygen out of the iron mass would probably take longer than the age of the solar system. In addition, iron meteorite falls typically contain at least a few inclusions of troilite, schreibersite, cohenite, graphite, etc. that would not form by reduction of FeO. So, I'm afraid that I don't believe that we're missing real meteorites by categorizing Ni-free iron masses as meteor-wrongs. Alan - Original Message - From: cdtuc...@cox.net To: Jeff Grossman jgross...@usgs.gov; meteoritelist meteorite-list@meteoritecentral.com Sent: Friday, March 26, 2010 11:06 AM Subject: Re: [meteorite-list] Nickel free metal in Meteorites Jeff, Thank you for your well explained points. As I have said many times before, you would make an excellent teacher as your answers always stimulate more thoughts. On that note. you acknowledge that nickel free metal does exist but, from reduced metal and is very small. With all due respect. Isn't size a relative thing? I mean looking at things on our scale the size of Nickel free metal in chondrules is small. So, doesn't this means it could be bigger? Look no farther than our own planet. We are way different than other planets. I have been told by Scientists that the earth is so diverse that it makes identification of meteorites difficult. This because Earth can and does have so many different types of rocks. And this is just one planet. So, going back to scale. What if this Reducing of Fe O that turns it into nickel free iron happens to be really big? Say the scale more like Artares which makes Earth look like a grain of sand? Based on our current method of weeding out meteorwrongs we may never know if really big reduction occurs because as part of the weeding process we eliminate all metal objects that do not contain nickel. And this reduction process as you say is a known fact. I see more abstracts based on theory than on nickel free iron facts. Another size scale dilemma is also acknowledged in meteorites. They say ( tongue in cheek) this is either a very large inclusion and the rest of the meteorite is missing. Or this is the whole thing. This is the case with irons. Sometimes the iron is nearly pure and other times it is mixed with silicates as in meso's. But again the point is that these small bits of nickel free iron could be big but we will never know. It seems to me if we paid more attention to morphology and find location and less on nickel content (as a must) that we would discover an iron without nickel. Maybe not as big as Hoba but not as small as what was found in HAH 237 CBb either. I believe this nickel free iron was also found in one of the Kalahari Lunar's. Is that from a chondrule also? This particular meteorite HAH 237 is the one they used recently to reset the date of our solar system but not important enough to open our eyes to the lack of nickel in bigger meteorites. I don't get it? I understand there is always a story. This thing fell through the roof Okay, does it look man made? Does it have serial numbers on it? Is it identifiable as an object of any kind like a piece of a tree shredder blade? If these answers are no then maybe just maybe it did fall from the sky? (NJ meteorite). In this example it was determined to be possible space junk and yet nobody bothered to show which space object it could have come from. This object would have had a significant amount of not only monetary value but scientific as well. What was this stainless steel chunk of metal doing up in space? Why would NASA have misplaced such a strange piece of stainless steel? The science was dropped but, it came from somewhere. We may never know from where though. We dropped the ball on NJ and we may be dropping balls every day from a lack of nickel. Heaven forbid we find the first large nickel free iron! Obviously it would be rare but, there are known ungrouped irons that are equally rare. Just another question. Carl -- Carl or Debbie Esparza Meteoritemax Jeff Grossman jgross...@usgs.gov wrote: Ni-free metal occurs within chondrules that have experienced reduction during melting. These chondrules were originally mostly free of metal and therefore free of Ni, but contained oxidized iron (FeO) in the silicate minerals. During reduction, the FeO was converted into Fe metal (if the
Re: [meteorite-list] Nickel free metal in Meteorites
- Original Message - From: cdtuc...@cox.net To: Alan Rubin aeru...@ucla.edu; meteoritelist meteorite-list@meteoritecentral.com Sent: Friday, March 26, 2010 12:23 PM Subject: Re: [meteorite-list] Nickel free metal in Meteorites Alan, Wow, I appreciate that your points are put in terms I can follow but Would you be so kind as to explain a bit better for me to understand? Again, I respect you enough to hear what you are saying but, you lost me in some of your points. I will question below in all caps. No, I'm not yelling. Thanks. -- Carl or Debbie Esparza Meteoritemax Alan Rubin aeru...@ucla.edu wrote: Low-Ni or Ni-free iron doesn't occur just in some chondrules. It is also found in impact-melt-rock clasts in ordinary chondrites and at the edges of olivine grains in ureilites. SO, THIS MAY EXPLAIN THE KALAHARI FIND OF THIS NICKEL FREE IRON? AND YOUR INPUT IS HIGHLY APPRECIATED HERE. I'm afraid I don't know anything about this. These rocks have experienced localized in situ reduction of FeO to metallic Fe as Jeff has pointed out. But let's look at the context, these low-Ni metallic iron grains are situated within mafic silicate grains that have lots of SiO2, MgO and (away from the reduced metal) FeO. They are formed in the solid state. A large iron meteorite isn't situated within a mass of mafic silicate. You could argue that it broke off, but this also wouldn't work. Diffusion of oxygen out of the iron mass would probably take longer than the age of the solar system. ARE WE TALKING 13 BILLION YEARS HERE (BIG BANG) ? OR 4.6 BILLION? WHY COULD THIS NOT HAVE OCCURRED AT THE TIME OF BIG BANG .THIS WAS VERY HOT AND QUICK? I was talking about the age of the solar system, circa 4.6 billion years. There was no iron at the time of the Big Bang: only hydrogen, helium and a little lithium. The heavier elements (up to iron) were forged later in stars by normal fusion processes and did not enter the interstellar medium until these stars died. Iron and heavier elements were made in supernova explosions of heavy stars and spewed into the interstellar medium. In addition, iron meteorite falls typically contain at least a few inclusions of troilite, schreibersite, cohenite, graphite, etc. that would not form by reduction of FeO. RESPECTFULLY, EXACTLY MY POINT. HOW WOULD WE EVER KNOW IF THESE THINGS ARE IN A ROCK THAT WE DISMISS BECAUSE IT HAS NO NICKEL? SEEMS TO ME THERE SHOULD BE A BETTER WAY. I have looked at a lot of iron meteorwrongs and they do not include troilite, schreibersite, and cohenite. So, I'm afraid that I don't believe that we're missing real meteorites by categorizing Ni-free iron masses as meteor-wrongs. JUST ASKING. I JUST DON'T GET HOW NICKEL IN AN IRON CAN BE 3 TO 60 PERCENT AND NOT ZERO PERCENT? ESPECIALLY NOW THAT WE KNOW ZERO PERCENT DOES EXIST IN SPACE. SOMETHING DIFFERENT MIGHT BE GOING ON? Metallic Fe can form in two ways. Cosmochemists surmise that at the beginning of solar-system history there was a hot and cooling gas of solar composition at low pressure. If we assume a certain pressure, say 1/10,000 of an atmosphere, the we can calculate the temperatures at which different elements condense as solids from the gas. Metallic Ni condenses at 1354 K; metallic Fe condenses at a slightly lower temperature, i.e., 1337 K. The iron is expected to condense on the Ni grains to form a solid solution of metallic Fe-Ni. As temperatures drop, these grains will coarsen. At much lower temperatures, some of the metallic Fe will react with oxygen and form FeO. This component is generally incorporated into silicate minerals. A chondrite will generally contain grains of metallic Fe-Ni and silicates that contain FeO. Except in the most oxidized chondrites, e.g., R and CK, there is little NiO in the olivine. So, when we have localized in situ reduction, we can form low-Ni metallic Fe from the silicates occurring inside the silicate grains. Please note that volumetrically, the amount of low-Ni metallic Fe is trivial, far less than 0.1% of a typical chondrite. The bulk of the metal grains outside these silicates will be largely unaffected, except that they may have somewhat enhanced Fe/Ni ratios at their margins. Bulk melting of these rocks will merge all of the metal and it will have essentially the cosmic Fe/Ni ratio. Igneous processes such as fractional crystallization in metallic magmas in the cores of differentiated asteroids will change the Fe/Ni ratio of different samples leading to the variety in the irons we see today. THANK YOU AGAIN FOR YOUR HELP. CARL Alan - Original Message - From: cdtuc...@cox.net To: Jeff Grossman jgross...@usgs.gov; meteoritelist meteorite-list@meteoritecentral.com Sent: Friday, March 26, 2010 11:06 AM Subject: Re: [meteorite-list] Nickel
Re: [meteorite-list] QUESTION RE METEORITES AND POP CULTURE
If we go back a bit (and as I pointed out in Disturbing the Solar System), there is H. P. Lovecraft's 1927 horror story, The Colour out of Space, wherein sinister space seeds within an iron meteorite poison the plants, animals and people living on the farm where the meteorite fell. __ Visit the Archives at http://www.meteoritecentral.com/mailing-list-archives.html Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
Re: [meteorite-list] Three Martian Meteorites Triple Evidence for MarsLife
I found that Dave McKay's recent quote that we do believe that we are very, very close to proving there is or has been life (on Mars) is analogous to that of Percival Lowell when he founded his observatory in Flagstaff, Arizona in 1894. Lowell said that the purpose of the observatory was to undertake an investigatioon into the condition of life in other worlds including...their habitability by beings like or unlike man. He went on to say that there was strong reason to believe that we are on the eve of pretty definite discovery in the matter. - Original Message - From: Ron Baalke baa...@zagami.jpl.nasa.gov To: Meteorite Mailing List meteorite-list@meteoritecentral.com Sent: Sunday, January 10, 2010 6:16 PM Subject: [meteorite-list] Three Martian Meteorites Triple Evidence for MarsLife http://www.spaceflightnow.com/news/n1001/09marslife/ Three Martian meteorites triple evidence for Mars life BY CRAIG COVAULT SPACEFLIGHT NOW January 9, 2010 The team that found evidence of Martian life in a meteorite that landed in Antarctica believes that during 2010, by using advanced instrumentation on now three Martian meteorites, it will be able to definitively prove whether such features are truly fossils of alien life on the Red Planet. This new information goes well beyond the updated findings released by NASA in November 2009 about signatures for magnetic type bacteria. We do not yet believe that we have rigorously proven there is [or was ] life on Mars. says David S. McKay, chief of astrobiology at the NASA Johnson Space Center. But we do believe that we are very, very close to proving there is or has been life there, McKay tells Spaceflight Now. The possibility of life on Mars has become a scientific issue of profound importance and great public interest, Michael Meyer, the NASA Headquarters senior scientist for Mars exploration, told an audience of several hundred scientists at the recent American Geophysical Union meeting in San Francisco. And in a 2009 editorial, The Economist, a highly regarded British publication, also noted the explosion of both public and scientific interest in Mars saying the possibility of life on Mars is too thrilling for mankind to ignore. In the mid-1990s, when the JSC team found what it interprets as Martian fossils inside a meteorite that landed near Allen Hills in Antarctica, it was the only example at the time of suspected fossils in a meteorite from Mars. The team, however, believes it has since tripled its fossil-like data by finding more biomorphs (suspected Martian fossils) inside two additional Martian meteorites, as well as more evidence at other spots in the Allen Hills meteorite itself. Remarkably, some of the most striking new evidence for life on Mars is being found inside in a meteorite that has been sitting in the British Museum of Natural History in London for nearly 100 years, says McKay. Had British researchers examined their Nakhla meteorite with readily available electron microscopes and other tools like those used by the U.S. team, the new evidence for life on Mars could have been a British discovery, rather than an American one. The Houston-based scientists believe the age spread of their data, from 3.6 billion to 1.4 billion years ago, shows that a planet-wide network of micro-organisms came to life underground on Mars 3.6 billion years ago during the first billion years after Mars had formed along with the rest of the planets in the solar system. Mars was much warmer and wetter with a much thicker atmosphere then. Simple life forms were beginning to form on Earth at about the same time. Scientists are able to tell that the meteorites came from Mars by measuring the noble gases trapped in the rocks and also by their geologic character. The noble gas ratios measured to determine Martian origin are helium, neon, argon, krypton, xenon and radon. The twin Viking landers of the mid-1970s measured Martian surface gas compositions in great detail, and the now more than 80 meteorites have been found and designated as being from Mars. They all have internal gas compositions that match the Viking lander data, as well as Mars rock compositions measured by spacecraft at the planet. Similar biological type findings in three different meteorites that also correlate well with ancient Earth organisms considerably broaden the evidence for at least past life on Mars, says geologist Everett K. Gibson, co-leader with McKay and Kathie Thomas-Keprta on the JSC Mars life study team. According to the JSC team, the three Martian meteorites with the apparent fossil signatures include what appear to be mats of bacteria and specific other biological signatures that are common to all three meteorites. They are also highly similar to undisputed micro-fossil life of ancient organisms found in Earth's rocks like Columbia river basalts in Washington state. In its November update, the Mars team said that for more than a decade after the Martian
Re: [meteorite-list] Meteorite hits and Kills Man
Spike TV interviewed me a few months ago for a Death-by-Meteorite show. Of course, I never saw the video and I have no idea what they will include of the interview. Although they never told me what show I would be on, I suppose it is on this one. I do admit that I was at that Woodland Hills party; I had calculated when that meteorite would fall and positioned that annoying guy in the right spot. I retrieved the meteorite from the pool and swore everyone to silence. (I later sold the meteorite on ebay as a Campo.) The plan was perfect except for having forgotten about the guy with the video camera from Spike TV who had also come to the party. Alan Rubin - Original Message - From: Ruben Garcia mrmeteor...@gmail.com To: Meteorite List meteorite-list@meteoritecentral.com Sent: Tuesday, December 08, 2009 7:37 PM Subject: [meteorite-list] Meteorite hits and Kills Man It must be true Spike TV wouldn't lie. http://www.youtube.com/watch?v=sfT5onJJrgk -- Rock On! Ruben Garcia Website: http://www.mr-meteorite.net Articles: http://www.meteorite.com/blog/ Videos: http://www.youtube.com/profile?user=meteorfright#p/u __ http://www.meteoritecentral.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list __ http://www.meteoritecentral.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
Re: [meteorite-list] Chondrule formation
The question was raised if chondrules occur in achondrites or moon rocks. If you look back at papers from 1970 - 1972, there are reports of lunar chondrules found in the first returned Apollo samples. These chondrules, as nearly everyone acknowledges, are millimeter-size impact-melt spherules produced after collisions of meteorites with the lunar surface. Some folks think that chondrules in chondrites also formed this way, but most chondrule researchers believe that chondrules were formed as isolated droplets in the solar nebula. If this is correct, then after being melted, they would have cooled quickly because there was little or no insulating material around them. Only later would these chondrules accrete along with CAIs, matrix, metal and sulfide assemblages, etc. to form planetesimals which later accreted into larger bodies. If chondrules indeed formed as isolated droplets in the nebula, then if the planetesimals into which they subsequently accreted ever melted, then the chondrules would also melt and the textural evidence for them would be forever erased. Alan Rubin - Original Message - From: Greg Stanley stanleygr...@hotmail.com To: epgrond...@yahoo.com; meteorite-list@meteoritecentral.com Sent: Friday, October 02, 2009 1:51 PM Subject: Re: [meteorite-list] Chondrule formation Hello All: I had a thought: It seems to me that chondrules are prevalent in meteorites blasted from asteroidal bodies and not from planetary bodies. For example, do chondrules exist (or have been found) on any meteorites from the moon, mars or maybe from Mercury (Angrites?)? Now I understand that these are called achondrites, and thus they do not have chondrules, but it seems that chondrites are only from asteroidal bodies (or perhaps comets). With that said, maybe there is a relationship between formation of rock without gravity (or a very small amount of gravity); chondrules form initially during the formation of the solar system, and then later over millions of years are altered on planetary bodies under a gravitational force. Just my two cents worth. Greg S. Date: Fri, 2 Oct 2009 11:58:02 -0700 From: epgrond...@yahoo.com To: meteorite-list@meteoritecentral.com Subject: Re: [meteorite-list] Chondrule formation Hi all - We don't know crap... Hey!, who stole my line? But that's okay, I can come up with another one: We don't know crap about the impact hazard, and NASA senior managers know less than that. E.P. Grondine Man and Impact in the Americas __ http://www.meteoritecentral.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list _ Hotmail: Trusted email with Microsoft’s powerful SPAM protection. http://clk.atdmt.com/GBL/go/177141664/direct/01/ __ http://www.meteoritecentral.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list __ http://www.meteoritecentral.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
Re: [meteorite-list] CAI and chondrules
The origin of chondrules is one of the outstanding problems facing meteorite researchers. There is significant disagreement even among colleagues who routinely work together on this problem. But be aware, nearly everything I say below will be disputed by some folks in the field, each highlighting a separate area of contention. I think that many researchers would agree that most presently existing chondrules formed in the solar nebula by melting pre-existing solid objects (let's call them dustballs) that contained chunks of pre-existing chondrules and some nebular dust. Many chondrules may have experienced more than one melting event. Chondrules with relict grains melted more than once; enveloping compound chondrules contain components that experienced different melting events; chondrules with igneous rims melted more than once. Enveloping compound chondrules with igneous rims (rather common in CR chondrites) were melted at least three times. During melting it is likely that some volatiles escaped from chondrules and condensed onto adjacent dust. Some metal and some sulfide also likely escaped from many chondrules during melting. It is also likely that barred olivine and cryptocrystalline chondrules were essentially completely melted during their final melting event, but that porphyritic chondrules were only incompletely melted. Melting episodes were either of short duration or occurred in the presence of sufficient amounts of gas to avoid fractionation of K isotopes. Melting experiments that produce artificial chondrules have provided useful constraints on chondrule cooling times, which are probably on the order of a few minutes. Chondrules in different chondrite groups vary in size, O-isotopic composition, proportion of different textural types, proportions of chondrules sporting igneous rims, and the proportion of compound chondrules. These differences have only been described to a limited extent; much more work needs to be done. Different chondrite groups also vary in their CAI and amoeboid olivine inclusion (AOI) populations. It isn't clear what the relationship is (if any) between a chondrite group's chondrules and CAIs. Some researchers favor the idea that chondrules were formed by flash-melting mechanisms such as lightning in the nebula; quite a few favor melting of pre-existing dustballs by gas dynamic shock waves. A vocal minority believes that chondrules formed by planetesimal collisions. I think that most chondrules formed in the nebula by repeated episodes of flash melting but that some chondrules (e.g., most of those in CH chondrites and Bencubbin-like (CB) chondrites) may have formed by impact-related processes. It is also possible that rare varieties of chondrules in ordinary chondrites (e.g., chromite-bearing chondrules) were formed by impact melting. Another problem confronting researchers is that chondrules were affected by parent-body processes after the chondrules formed and were incorporated into asteroids. Such secondary processes include thermal metamorphism, impact heating, brecciation, and aqueous alteration. And, of course, chondrules in meteorite finds may have been affected by terrestrial weathering. We need to look beyond these processes and infer what the chondrules were like prior to accretion when they were isolated dustballs in the nebula. This is a difficult task, but, as Jeff Grossman said, progress is being made. Alan Rubin - Original Message - From: Alexander Seidel g...@gmx.net To: Jeff Grossman jgross...@usgs.gov; meteorite-list@meteoritecentral.com Sent: Thursday, October 01, 2009 12:57 PM Subject: Re: [meteorite-list] CAI and chondrules From my layman´s perspective and point of view: isn´t it interesting to note that there is still **so much** controversy over chondrule formation, those little round objects which are so evident and very clearly visible in many of the meteorites in our collections, while at the very same time all the basic physical conditions and evolutionary laws even on small timescales seem to be quite well understood? But then again all the many empirical facts obviously still have to come under serious scrutiny to finally have, at best, sort of a generally accepted truth emerge: a mainstream theory of chondrule formation that will be agreed upon by most scientists - one of these days. Fascinating, especially in this era where many basic things seem to be understood! I´m excited to learn more about this, as time goes by... :-) Alex Berlin/Germany Original-Nachricht Datum: Thu, 01 Oct 2009 14:52:08 -0400 Von: Jeff Grossman jgross...@usgs.gov An: meteorite-list@meteoritecentral.com Betreff: Re: [meteorite-list] CAI and chondrules I didn't say we don't know cr*p... I said there was not a definitive answer. We know a lot about the timing, materials, and physical conditions needed to make
Re: [meteorite-list] Chondritic parent bodies
There are some porous chondrites but as far as I know there is no reason to believe that they are from separate bodies. They may have suffered more (or less) impact-induced compaction than the majority of rocks. But one should check their cosmic-ray exposure ages, shock ages, etc. to see if they share some of these characteristics with their colleagues. Alan Rubin - Original Message - From: Meteorite-Recon.com i...@niger-meteorite-recon.de To: Meteorite-list@meteoritecentral.com Sent: Wednesday, September 09, 2009 6:21 AM Subject: Re: [meteorite-list] Chondritic parent bodies Hi Jeff, others, certainly true as far as the majority of L-chondritic material is concerned. But Dave’s question is in so far justified as there are several exceptional L-chondrites that show particular differences in their lithology compared to other L-chondrites. If my information on this subject isn’t out of date, the group of L-chondrites around Mt. Tazerzait, Baszkówka and Tjerebon are believed to originate from a different parent body as the other L-chondrites. If my memory doesn’t cheat me in this matter these chondrites show a lesser degree of compaction and a high amount of interstitial pores with growth of euhedral to anhedral crystals in these vugs. A group around A. Pilski even argued that these crystals provide evidence for hydrothermal activity in the particular mother body of these L-chondrites. Perhaps someone wants to look up the cosmic ray exposure data on the Mt. Tazerzait grouplet to see if a different shock event played a role in the production delivery of these meteorites ... I am clearly not an expert in this field so please beat me if I’am wrong here. Cheers Svend www.meteorite-recon.com --- Jeff Grossman wrote: I'm not sure why you thought there was a definition that requires L5 and L6 chondrites to come from different parent asteroids... there isn't. Questions like this are open to investigation. Isotopic data show that the different petrologic types of L chondrites all experienced a major shock event around 500 million years ago, which means that at least many of them came from a single parent body. Similarly, different petrologic types of H chondrites show evidence for a break-up event around 7.5 million years ago. There is still debate over the importance of onion shell vs. rubble pile models of the asteroids, but not so much over whether the different petrologic types come (or came) from a single asteroid. jeff At 11:40 PM 9/8/2009, Dave Gheesling wrote: All, Pete's question re: pallasites reminds me of one I've been meaning to throw out to the group for a while. I believe that, by definition, L6's come from one parent body and L5's, say, come from another. It's clear why breccias might simply be an association of the two. But I've seen cross section illustrations of hypothetical asteroids more than once which indicate a transitional progression from L3 material at the exterior/crust through L4, then L5, and eventually to L6 at the center/core. Presumably this is due to insulative properties and the like towards the interior which allow more heat from radioactivity to build up, etc, but this also seems to indicate a single parent body. I'm sure Sterling Co. might have a field day with this one, and I'm looking forward to any responses out there... Thanks much, Dave Dave Gheesling IMCA #5967 www.fallingrocks.com __ http://www.meteoritecentral.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list Dr. Jeffrey N. Grossman phone: (703) 648-6184 US Geological Survey fax: (703) 648-6383 954 National Center Reston, VA 20192, USA __ http://www.meteoritecentral.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list -- www.meteorite-recon.com __ http://www.meteoritecentral.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list __ http://www.meteoritecentral.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
Re: [meteorite-list] Chondritic parent bodies
The general supposition is that all L chondrites come from one parent body, that H chondrites come from another, etc. We don't know this to be strictly true, but there is evidence that it is broadly true. For example, about two-thirds of all L chondrites (of different petrologic types) were shocked about 470 Ma ago or so, indicating that they were on the same parent body at that time. Similarly, nearly half of all H chondrites (of different petrologic types) have a cosmic-ray exposure age of about 7.5 Ma indicating that they were all within about a kilometer of each other (or so) at that time. The idea that the parent bodies were stratified with the type-6 chondrites in the center and type-5s closer to the surface, etc. is known as the onion shell model. There is some evidence for it and some against it. Hence, some researchers are strong advocates and others reject the model. As is clear, the situation is not yet resolved. Alan Rubin - Original Message - From: Dave Gheesling d...@fallingrocks.com To: 'Meteorite List' meteorite-list@meteoritecentral.com Sent: Tuesday, September 08, 2009 8:40 PM Subject: [meteorite-list] Chondritic parent bodies All, Pete's question re: pallasites reminds me of one I've been meaning to throw out to the group for a while. I believe that, by definition, L6's come from one parent body and L5's, say, come from another. It's clear why breccias might simply be an association of the two. But I've seen cross section illustrations of hypothetical asteroids more than once which indicate a transitional progression from L3 material at the exterior/crust through L4, then L5, and eventually to L6 at the center/core. Presumably this is due to insulative properties and the like towards the interior which allow more heat from radioactivity to build up, etc, but this also seems to indicate a single parent body. I'm sure Sterling Co. might have a field day with this one, and I'm looking forward to any responses out there... Thanks much, Dave Dave Gheesling IMCA #5967 www.fallingrocks.com __ http://www.meteoritecentral.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list __ http://www.meteoritecentral.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
Re: [meteorite-list] Chondritic parent bodies
Of course this abstract was superceded by the paper: Dixon, Bogard, Garrison and Rubin (2004) 39Ar-40Ar evidence for early impact events on the LL parent body. GCA 68, 3779-3790. - Original Message - From: bernd.pa...@paulinet.de To: Meteorite-list@meteoritecentral.com Sent: Wednesday, September 09, 2009 9:47 AM Subject: [meteorite-list] Chondritic parent bodies Hello Dave, Alan, and List, Here is a paper that may be of interest with regard to LL chondrite parent bodies: Dixon E.T., Bogard D.D. and Garrison D.H. (2002) 40Ar-39Ar Chronology of LL Chondrites (Lunar and Planetary Science XXXIII, 1114.pdf). They even discuss *three* models: 1. The onion-shell model 2. The rubble-pile model 3. The re-assembly model Best wishes, Bernd __ http://www.meteoritecentral.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list __ http://www.meteoritecentral.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
Re: [meteorite-list] Chondritic parent bodies
John Wasson and I classified some meteorites as L/LL because we were uncertain of their proper classification. Typical for these meteories, some properties indicate L, some indicate LL, and some could be truly intermediate between the established ranges. This may mean that they are anomalous L chondrites, anomalous LL chondrites or, possibly, from a different parent body entirely that is intermediate in its properties. Of course, some could be L, some could be LL and some could be intermediate. One way to decide would be to accumulate a lot of data on these guys and see if they have a cosmic-ray age peak that matches one of the main ones for L or LL or if it is unique. This remains to be done. Alan - Original Message - From: Dave Gheesling d...@fallingrocks.com To: bernd.pa...@paulinet.de; Meteorite-list@meteoritecentral.com Sent: Wednesday, September 09, 2009 11:15 AM Subject: Re: [meteorite-list] Chondritic parent bodies Bernd, Alan, and List, Thank you both for the diplomatic and informative responses. While we're on the subject, might one of you (or anyone else) expand on, say, the L/LL6 classification designation? Holbrook was recently moved from an L6 to such a classification, and I have a few others in my collection which are not breccias (and presumably are entirely from one parent body and not two) but yet have this classification assigned to them...which, by definition, would imply connection with both the L and LL parent bodies, presumably anyway. Thanks, and all best, Dave www.fallingrocks.com -Original Message- From: meteorite-list-boun...@meteoritecentral.com [mailto:meteorite-list-boun...@meteoritecentral.com] On Behalf Of bernd.pa...@paulinet.de Sent: Wednesday, September 09, 2009 12:47 PM To: Meteorite-list@meteoritecentral.com Subject: [meteorite-list] Chondritic parent bodies Hello Dave, Alan, and List, Here is a paper that may be of interest with regard to LL chondrite parent bodies: Dixon E.T., Bogard D.D. and Garrison D.H. (2002) 40Ar-39Ar Chronology of LL Chondrites (Lunar and Planetary Science XXXIII, 1114.pdf). They even discuss *three* models: 1. The onion-shell model 2. The rubble-pile model 3. The re-assembly model Best wishes, Bernd __ http://www.meteoritecentral.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list __ http://www.meteoritecentral.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list __ http://www.meteoritecentral.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
Re: [meteorite-list] Let's talk about meteorites
Several folks have brought up interesting questions and I'll try to answer them. But, first of all, I have to admit that I'm not an expert on iron meteorites. There are many other researchers, including a few members of this list, who are far more knowledgeable than I am. John Wasson has recently grouped various IAB and IIICD irons and some ungrouped irons into a IAB complex. These may be all from one asteroid, or perhaps from several. They all have broadly similar metal compositions and do not display element-element (e.g., Ir-Ni) concentration plots that appear consistent with the fractional crystallization processes that are believed to occur in the cores of molten asteroids. The silicates in these irons also have the planetary-type rare gas abundances that we see in chondrites but not in eucrites, presumably because they were volatilized during the extensive melting that eucrites experienced. This suggests that the silicates in these irons were rapidly cooled. This is consistent with the model that they were derived from chondrites as is their approximately chondritic bulk compositions. Now, the question of why these irons display nice Widmanstatten patterns that appear consistent with slow cooling over millions of years... I suspect that this is not due to monotonic cooling but rather to annealing, perhaps induced by impact heating processes. If an impact on a chondritic asteroid causes localized melting, metal and silicate segregation and metal pooling on the crater floor (as in this model), then the slow cooling indicated by the metal might be due to burial beneath well-insulated debris (perhaps impact ejecta); such material would have a low thermal diffusivity and would promote relatively slow cooling. Could it be slow enough to cause a Widmanstatten pattern? I don't know, but repeated impacts over the course of millions of years could cause periodic episodes of annealing. This might (or might not) work. Although there may seem to be an inconsistancy between the fast cooling of the silicates and the slow cooling of the metal, this can be readily accommodated. Once the silicates quench and the planetary gas is essentially sealed in, then they could be annealed without much of the gas leaking out. It is important to note that not everyone agrees with the impact-melting model for the IAB-IIICD and IIE irons. Others would argue that these irons did form in differentiated asteroids, perhaps in cores, perhaps in isolated pods in the mantle that never sank to the asteroid center. I'm not convinced by these models, but perhaps this exchange will prompt one of the advocates to explain it. Alan - Original Message - From: Mr EMan mstrema...@yahoo.com To: Carl 's carloselgua...@hotmail.com; meteorite-list@meteoritecentral.com; Alan Rubin aeru...@ucla.edu Sent: Friday, September 04, 2009 6:36 AM Subject: Re: [meteorite-list] Let's talk about meteorites --- On Thu, 9/3/09, Alan Rubin aeru...@ucla.edu wrote: snip... The metal liquid sank to the crater floor, incorporated some rapidly melted silicate debris andcooled. This is a controversial model and not universally accepted. I think this theory has a potential fatal flaw if what we think we know about taenite/kamacite growth is valid. Without an insulating blanket the molten pool will not exist in a molten state long enough to permit crystallization aka Widmanstatten patterns. Be it remembered that Widmanstatten pattern/crystal growth is very very slow on the order of 10's of degrees cooling per million years. It is difficult to develop a scenario that integrates a large crater on an Goldilocks Asteroid which works. Goldilocks: Not too small as escape velocity is so low there is no fall back/re-accretion to bury the melt; Not too large as the asteroid would have already differentiated into a metallic core...so it has to be just right, at the threshold of the larger size with sufficient gravitational acceleration to not just recapture ejecta but to do it rapidly enough to insulate the molten metal. I envision a steeply conical deep crater which could minimize the amount of fall back ejecta to cover the surface. keep the pool--if in fact, such one exists. This scenario also requires to nearly identical impacts; one down the throat of another, millions of years apart. This tends to disfavor the crater floor theory on just the statistics. It would be interesting to locate a crater on an asteroid that fits the definition of Dewar flask. Popigai, here on earth had the depth and fall back to insulate a 600m melt on the crater floor and it only stayed molten for a few thousand years Not millions! This was a scenario that was given all benefit of favorable condition and still could not stay molten long enough. I can see why this theory has some doubters. Were we able to find a rapidly quenched FeNi meteorite without the Widmanstatten marker than I could
Re: [meteorite-list] Let's talk about meteorites
There are three principal goups of silicated iron meteorites: the IAB-IIICD, IIE and IVA groups. Recent work seems to indicate that the IAB and IIICD groups are related. Iron meteorites that are thought to have formed by fractional crystallization processes have certain slopes on element-element diagrams (e.g., Ir-Ni) that match those expected by fractional crystallization, presumably located in cores. The IVA irons exhibit such trends and so are presumably from the core of a differentiated asteroid. A few IVA irons contain small grains of silica. The IAB-IIICD irons do not exhibit trends on element-element diagrams consistent with fractional crystallization. Some researchers (e.g., John Wasson) believe that they are not from cores but are rather from impact pools on chondritic asteroids. Their silicates are basically chondritic in bulk composition and even contain the so-called planetary gases as are found in chondrites but not differentiated meteorites. The IIE irons have alkali-rich silicates. These silicates are not chondritic in composition but do have planetary gases. The metal portion of these iron meteorites also do not conform to the slopes expected for fractional crystallization. They also may have formed as impact pools on chondritic asteroids. The alkali-rich silicates, I believe, formed because feldspar has a low impedance to shock compression and hence melts first during shock events. The IIE silicates are similar in composition to impact-melt pockets in ordinary chondrites. Mesosiderites are differentiated meteorites. Their metal may have been derived from a core. Their silicates are basically eucrite and diogenite material. I modeled mesosiderites as having formed via the collision of a core (with some overlying mantle) to the basaltic surface of another asteroid. Alan Rubin __ http://www.meteoritecentral.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
Re: [meteorite-list] Let's talk about meteorites
Sorry,, but I guess I was not clear. The only group of silicate-bearing irons widely agreed to have come from an asteroid core is the IVA group. This group has little silicate, mainly small grains of silica, which some think may have been vapor deposited in the core. There are no collisions involved in forming the IVA irons except the one or ones that shattered their parent differentiated asteroid and liberated them. The other silicated irons, i.e., the IAB, IIICD and IIE groups, may be from chondritic, not-differentiated asteroids, that never experienced global melting. These irons may have formed after an impact into the chondritic surface of these bodies involving local melting and separation of the metallic and silicate liquids because they were immiscible. The metal liquid sank to the crater floor, incorporated some rapidly melted silicate debris and cooled. This is a controversial model and not universally accepted. Mesosiderites are differentiated rocks consisting of roughly half metal and half silicate. The silicate is basically basalt and orthopyroxenite, i.e., eucrite and diogenite material. The metal is similar to that of the IIIAB iron meteorites (a differentiated iron group) and so is most likely from the core of a differentiated (i.e., globally melted) asteroid. My model from some years ago was that the iron core (plus overlying mantle) of the projectile impacted the basaltic/orthopyroxenitic surface of another (target) asteroid and formed the mesosiderites. The large gabrroic clasts in many of the mesosiderites seem to have formed by two or more episodes of impact melting, and grain settling. Their origin appears rather different from that of the silicated irons. Alan - Original Message - From: Carl 's carloselgua...@hotmail.com To: meteorite-list@meteoritecentral.com Sent: Thursday, September 03, 2009 4:42 PM Subject: Re: [meteorite-list] Let's talk about meteorites OK, I think I see the subtle difference. I have had to re-read Dr. Rubin's post several times to get the picture (Thanks to MikeG, too). Simplified, an asteroid slams into another planetary body right to the iron core and forms mesosiderites. That part I knew, but when smaller iron asteroids slams onto larger rocky asteroids the surface layer forms the silicated irons. I would have thought that would also form mesosiderites, too. Hmmm. Very interesting. Thank you, Dr. Rubin. Carl _ With Windows Live, you can organize, edit, and share your photos. http://www.windowslive.com/Desktop/PhotoGallery __ http://www.meteoritecentral.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list __ http://www.meteoritecentral.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
Re: [meteorite-list] Acfer breccia - provisional classificationresults
It is very unusual to have one ordinary chondrite group mixed with another. Dimmitt (H regolith breccia) has an LL5 clast; St. Mesmin (LL regolith breccia) has some H clasts. Let's get this thing named officially through the Nomenclature Committee. Alan Rubin - Original Message - From: Rob Lenssen [EMAIL PROTECTED] To: Meteorite-list@meteoritecentral.com; [EMAIL PROTECTED] Sent: Friday, September 12, 2008 11:35 AM Subject: Re: [meteorite-list] Acfer breccia - provisional classificationresults Hi List, In January 2007, I posted a link ( http://home.planet.nl/~rlenssen/Acfer500g.htm ), pointing to some pictures of an odd looking meteorite, asking for comments. This request resulted - via List member Frederic Beroud - in a contact with Jerome Gattacceca from CEREGE in France, who conducted magnetic susceptibility measurements, and kindly offered to help to have it classified. Today I received (provisional) classification results, and want to share them with you: Provisional results by: M. Denise (MNHN)/J. Gattacceca (CEREGE) breccia LL6-L4 shock stage S2-S4 (S2 for the LL lithology and S4 for the L lithology) W1 Microprobe analysis (LL-L lithology) Fayalite 31.5±0.6-25.5±0.5 Fs 26.5±0.4-22.2±0.3 So, it turned out to be an LL6-L4 breccia! I wonder how rare this kind of breccia is, and especially if such a breccia has special scientific value, above just a mix of LL6 and L4 material. Does anybody know an answer to this? Kind regards, Rob Lenssen The Netherlands - Original Message - From: Rob Lenssen [EMAIL PROTECTED] To: Rob Lenssen [EMAIL PROTECTED]; [EMAIL PROTECTED]; Meteorite-list@meteoritecentral.com Sent: Wednesday, January 17, 2007 8:22 PM Subject: Re: [meteorite-list] Acfer breccia Hi Bernd + List, As promised, I added some photographs with better resolution. I made them through a magnifying lens. Light is not ideal, but better resolution it has. The first three detail pictures show the area near a dark clasts. Detail nr. 4 shows a 10mm droplett. Detail nr. 5 shows a 5mm dark spot with the largest metalic iron spot (in the polished planes) to it's right. http://home.planet.nl/~rlenssen/Acfer500g.htm Hope you enjoy it + maybe get some extra info out of it. regards, Rob - Original Message - From: Rob Lenssen [EMAIL PROTECTED] To: [EMAIL PROTECTED]; Meteorite-list@meteoritecentral.com Sent: Wednesday, January 17, 2007 12:05 AM Subject: Re: [meteorite-list] Acfer breccia Thank you very much for your reaction Bernd. Like I wrote before, it was covered in desert varnish when I got it. The two polished planes present fractured sides, that I planed removing as less material as possible. Before planing they already showed dark lumbs. Like it fractured around them. Don't think it is planetary though, as it is magnetic and shows the typical (chondrite) dots of iron in the surface. I will try to make better pictures and will share them with you. regards, Rob - Original Message - From: [EMAIL PROTECTED] To: Meteorite-list@meteoritecentral.com Sent: Tuesday, January 16, 2007 10:32 PM Subject: Re: [meteorite-list] Acfer breccia Hello Rob L. and List, Look what I found after cleaning and polishing a desert varnish covered Acfer: http://home.planet.nl/~rlenssen/Acfer500g.htm Dark clasts in lighter matrix. Also metal spots in the dark clasts. Any idea what this might be? In chondrites I typically see lighter clasts in darker matrix. What a beautiful Açfer chondrite! Is it a chondrite after all? The pictures should have a higher resolution. Are there any chondrules? Questions, questions, questions! Anyway, it does look quite fresh, so it should be something like W1 or W2 at most. It does look highly shocked ... at least S4 but more probably S5 or even S6. Well, that sounds like silicate darkening. Maybe the silicate clasts were not so very dark prior to the shock event but experienced extensive darkening (caused by melting of metal-sulfide). As for: In chondrites I typically see lighter clasts in darker matrix Here are some chondrites that have dark inclusions: NWA 0869, NWA 0978, NWA 1794, NWA 3346, OUED EL HADJAR, RICHFIELD, TANEZROUFT 061, etc., etc. Anyway, a mighty beautiful chondrite, something that, as Dean would now say you just gotta love! ... and if it is not a chondrite ??? Could this be a planetary meteorite??? Questions, questions, questions! Cheers, Bernd To: [EMAIL PROTECTED] Meteorite-list@meteoritecentral.com __ Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list __ Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list __ Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
Re: [meteorite-list] Names and synonyms (was ...Mali or Argelia...)
And, of course, if the name is mis-spelled originally, the mis-spelling persists as the official name: Forrest 001, Dyarrl Island (which should be Dyaul or Djaul), etc. Alan Rubin - Original Message - From: Jeff Grossman [EMAIL PROTECTED] To: meteorite-list@meteoritecentral.com Sent: Monday, October 22, 2007 3:25 PM Subject: [meteorite-list] Names and synonyms (was ...Mali or Argelia...) Here is what I can tell everybody about official names and synonyms. Every meteorite is given one, and only one, official name. This is the name that must be used in publications. There are no rules for how the name is chosen, only guidelines. Mainly the guidelines call for naming the meteorite after a nearby geographic feature that can be found on maps. If there are competing candidates for the name, weight may be given to many factors in choosing which to bestow, including existing usage among scientists and collectors, finder's privileges, distribution of specimens, and a little politics now and then. There are no rules at all concerning synonyms, although nowadays these are often vetted by the NomCom too. In general, these are any other names by which specimens of a meteorite may have been known throughout history. Synonyms are NOT official names. Sometimes you see officially recognized synonyms, meaning the NomCom has published it, but it's still not an official name. The NomCom usually tries to recognize synonyms when they have appeared in scientific publications, press reports, well-known catalogs, or when the meteorite is widely sold or traded under another name. One grayish area in all of this is named masses, like the Ahnighito, Agpalilik, Woman, Dog, and other masses of Cape York. Some of these names are so engrained that even scientists who have long studied them don't realize they aren't the official names, like Filomena. But these are also unofficial names: the official name for Filomena is North Chile. Nevertheless, the NomCom encourages the preservation of names of such masses on specimen labels and in catalogs, as they convey potentially important information about the provenance of a particular subsample. A good way of doing it would be to say North Chile (Filomena mass). Conversely, there is little value in preserving archaic names that do not carry specimen information, e.g., you would never refer to a Kirin mass of Jilin. jeff Dr. Jeffrey N. Grossman phone: (703) 648-6184 US Geological Survey fax: (703) 648-6383 954 National Center Reston, VA 20192, USA __ Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list __ Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
[meteorite-list] more anagrams
Ok, I have a few, too: NO EAR MASK AIR PUNCH WORD FEATHER A GRAIL MAN RON HID CART RICE TOYS Alan Rubin __ Meteorite-list mailing list [EMAIL PROTECTED] http://www.pairlist.net/mailman/listinfo/meteorite-list
[meteorite-list] organics in meteorites
It is fascinating to see the newpaper article posted by Mark Bostick on organic life in meteorites. For those of you who may be interested, I wrote about Hahn and Weinland in Chapter 17 of my new book, Disturbing the Solar System. Weinland was a zoologist and he named a species of coral he found in meteorites after Hahn. He called it Hahnia meteorica. He also believed the Widmanstatten pattern in the Toluca iron was composed of fossilized plants. Alan Rubin __ Meteorite-list mailing list [EMAIL PROTECTED] http://www.pairlist.net/mailman/listinfo/meteorite-list
[meteorite-list] meteorites on the Moon
Two meteorites found on the Moon have been named: Bench Crater and Hadley Rille. There are an additional two probable iron meteorite fragments, a 2-mm fragment recovered from the fines fraction of Apollo 11 regiolith sample 10085-18, and a 0.3x0.4-mm iron fragment from Apollo 16 regolith core sample 60014. Both Bench Crater and Hadley Rille were extensively heated when they impacted the lunar surface. This is reasonable because the peak in the relative velocity distribution of projectiles hitting the moon is 14 km/sec. Less than 2% of the prjectiles survive as unmelted fragments. As far as nomenclature is concerned, most scientists refer to lunar material blasted off the Moon and delivered to Earth as lunar meteorites. Meteorites found on the moon don't seem to have a special label and are simply referred to as meteorites from the Moon. Alan Rubin __ Meteorite-list mailing list [EMAIL PROTECTED] http://www.pairlist.net/mailman/listinfo/meteorite-list
[meteorite-list] Earth rocks ojn the Moon
About 10-15 yewars ago, Graham Ryder published an abstract about this. He concluded that rocks from the Earth's early crust would be mixed into the lunar regolith. These would be rocks no longer extant on the Earth. These materials would be of great scientific value, and for the record, should probably be called terrestrial meteorites. Alan __ Meteorite-list mailing list [EMAIL PROTECTED] http://www.pairlist.net/mailman/listinfo/meteorite-list
