Sergio, some clean & sharp images to have a gander at on a Sunday afternoon,
believe you have answers to your query so won't try to change your point of view. I'm guilty of using the tilt for inferring contacts or other linears-curvilinears for some time, two canned versions from two softwares and also scripting it in using one of the same software's channel math, it's use here goes back to the 1990s. An observation and counter-query, there looks like there's some displacement on cross lineaments seen on the SW? I don't recall any info about that area off the top of the head, or remember doing work on any projects in that particular area. That observation took about a couple seconds so won't spend more free time on that! Good rest of Sunday to you, saw a record breaking French Open result this a.m., cheerio for the rest of the day, Ed <https://www.avast.com/sig-email?utm_medium=email&utm_source=link&utm_campaign=sig-email&utm_content=webmail&utm_term=icon> Virus-free. www.avast.com <https://www.avast.com/sig-email?utm_medium=email&utm_source=link&utm_campaign=sig-email&utm_content=webmail&utm_term=link> <#DAB4FAD8-2DD7-40BB-A1B8-4E2AA1F9FDF2> On Sun, Oct 11, 2020 at 11:16 AM S E Geoscience and Exploration via SEGMIN < [email protected]> wrote: > Dear all, > > During my tenure at Goldcorp and also at previous positions, I delivered > short courses on Magnetics for the exploration geologist. I am sharing with > you two slides of that slides pool: one of TMI and one of the Tilt of TMI > of the same area. > > Some of you might recognize these data. It is in the North Cariboo belt > near Musselwhite mine (BIF) in Ontario. Since the inclination is 79 > degrees, I did not bother to calculate the RtP. > > Please let me know if you still believe that Tilt is a derivative :) > > Regards and happy thanksgiving !!! > > Sergio > > On Thu, Oct 8, 2020 at 6:35 PM S E Geoscience and Exploration < > [email protected]> wrote: > >> Andrew, >> >> Derivatives (or better said Gradients) are irrelevant? Not at all. They >> are heart and soul. >> >> First of all, the intensity of the field (be this Gravity, Magnetics, >> Electrical, Thermal, etc) is the gradient of the potential. >> >> In exploration, while Gradients ("Derivatives" in usual jargon) are used >> to map geometries, whether horizontal extensions, vertical emplacements, or >> both simultaneously, the Tilt is used to enhance or amplify the amplitude >> of deeper buried bodies. At the end of the day, the Tilt acts like an >> "amplitude equalizer" of the intensity. >> >> Just think how >> (1) the maximum intensity amplitude decreases with increasing depth of >> the source; >> (2) the flanks of the anomaly (or horizontal gradients) decrease with >> increasing depth of the source; >> (3) how the horizontal gradients reflect themselves again in the vertical >> gradients. >> >> Everything is explained in Laplace and Potential Theory. However, to make >> it simple, the model I use to explain to the non-geophysicist is the "heat >> radiator model". >> >> I have lots of geological examples. I could dig out some public data to >> show. >> >> Without writing any single mathematical formula, everytime I explain this >> to geologists using their own geological and geophysical data, they all >> understand. The only "formula" I show to them is the general relation in >> geophysical exploration as follows: >> >> Intensity of the anomaly == (contrast of the rock physical value) * >> (volume of the source) / (distance between sensor and source) >> >> Newton's equation is only an example of this relation. >> >> Regards >> >> Sergio.- >> >> On Thu, Oct 8, 2020 at 5:42 PM Andrew Long via SEGMIN < >> [email protected]> wrote: >> >>> Hi to all of you, >>> On the question of geophysical data, and such refinements as Verduzco, >>> or someone else, I would like to mention that depth of investigation is >>> key. The problem becomes more simple with depth as a result of entropy. >>> Henry's comment alludes to what we understand geologically. It all becomes >>> more simple as you traverse the Earth's traditionally geophysical Earth >>> concept. It's all about entropy and Einstein's concept of relativity. He >>> was right about the gravity, and Newton's doubtful equations that you all >>> use faithfully in exploration. >>> Tilt, derivatives, etc all irrelevant. Sorry. >>> Feel free to give me the full inquisition. >>> Andrew >>> >>> On Thu, 8 Oct 2020, 5:04 pm , <[email protected]> wrote: >>> >>>> >>>> >>>> >>>> Today's Topics: >>>> >>>> 1. Re: Tilt is not a derivative (S E Geoscience and Exploration) >>>> >>>> >>>> ---------------------------------------------------------------------- >>>> >>>> Message: 1 >>>> Date: Wed, 7 Oct 2020 16:13:26 -0400 >>>> From: S E Geoscience and Exploration >>>> <[email protected]> >>>> To: [email protected] >>>> Subject: Re: [SEGMIN] Tilt is not a derivative >>>> Message-ID: >>>> <CAN2kzWJA_1+Bc6NAvZ411=U= >>>> [email protected]> >>>> Content-Type: text/plain; charset="utf-8" >>>> >>>> Henry, >>>> >>>> it is definitely not a trick. Those orthogonal gradients are >>>> intertwined more than we think. The explanation is to be found in >>>> Potential >>>> Theory. >>>> >>>> Regards >>>> >>>> On Wed, Oct 7, 2020 at 4:03 PM Henry Lyatsky via SEGMIN < >>>> [email protected]> wrote: >>>> >>>> > Personally, I am no fan of tricks that combine such dissimilar beasts >>>> as >>>> > vertical and horizontal derivatives. Math is abstract and it can bear >>>> > anything, but we should remain skeptical when it comes to mixing >>>> apples and >>>> > oranges. For this reason, I also dislike the total gradient (analytic >>>> > signal). >>>> > >>>> > The mathematically simplest methods are best, combined with solid >>>> > geological thinking. >>>> > >>>> > *Henry.........................................................* >>>> > *Dr. Henry Lyatsky, P.Geoph., P.Geol.* >>>> > *cell: 403/710-7490 [email protected] <[email protected]>* >>>> > *Skype: henry.lyatsky* >>>> > *www.linkedin.com/in/lyatsky/* <https://www.linkedin.com/in/lyatsky/> >>>> > >>>> > *?This message and any attachments are confidential. Any >>>> redistribution >>>> > is strictly prohibited. If you are not an intended recipient, please >>>> > notify the sender and delete this message and attachments from your >>>> > system. Please check this message, links and attachments for >>>> viruses; we >>>> > accept no liability for any malware damage. Thank you.* >>>> > >>>> > ------------------------------ >>>> > *From:* SEGMIN <[email protected]> on behalf of S E >>>> > Geoscience and Exploration via SEGMIN <[email protected]> >>>> > *Sent:* Wednesday, October 7, 2020 1:43 PM >>>> > *To:* [email protected] <[email protected]> >>>> > *Cc:* S E Geoscience and Exploration < >>>> > [email protected]> >>>> > *Subject:* Re: [SEGMIN] Tilt is not a derivative >>>> > >>>> > Alan >>>> > >>>> > thank you for the comments. >>>> > >>>> > My point is that the term "Tilt Derivative" might be rather confusing >>>> for >>>> > non geophysicists, since they might tend to think that it is a >>>> derivative, >>>> > or a change of a parameter Y (e.g. Magnetic Induction B) in relation >>>> to >>>> > parameter X (e.g., Depth Z or Time t), which is not. >>>> > >>>> > "Derivative Tilt" is certainly more appropriate. When I explain the >>>> useful >>>> > parameter to the geoscientist who is not knowledgeable in potential >>>> > techniques, I tell them that it is a sort of "amplitude equalizer" in >>>> order >>>> > to enhance weaker and low frequency signals in order to see better in >>>> areas >>>> > with thick cover, so that they understand. >>>> > >>>> > Generally, I personally prefer to use the term "Gradient" instead of >>>> > "Derivative", for obvious reasons. But I understand that technical >>>> jargon >>>> > is deeply rooted. >>>> > >>>> > Thanks >>>> > >>>> > >>>> > >>>> > On Wed, Oct 7, 2020 at 11:47 AM Alan Reid via SEGMIN < >>>> > [email protected]> wrote: >>>> > >>>> > Folks, >>>> > >>>> > There?s a clear enough definition in the paper by Verduzco et al in >>>> The >>>> > Meter Reader (TLE February 2004). I believe they coined the term, so >>>> their >>>> > definition should stand. TDR (Tilt Derivative) is effectively the >>>> tilt of >>>> > the derivatives, They also define the ?TDR_THDR? which is the total >>>> > horizontal derivative of the TDR. I do not believe Verduzco et al were >>>> > trying to suggest that Tilt is a derivative. Its clearly not. >>>> > >>>> > Given that they defined and published the term, perhaps we should >>>> respect >>>> > that and not go off with our own names for this entity? Nor go off >>>> with >>>> > other definitions for the term? >>>> > >>>> > I confess that ?Derivative Tilt? might have been a more descriptive >>>> name, >>>> > but it somehow doesn?t have much of a ring, does it? Anyway, its >>>> useful as >>>> > described. And I teach it and use it in that form. >>>> > >>>> > I do not have any conflict of interest to declare, here. >>>> > >>>> > Regards >>>> > >>>> > Alan Reid >>>> > >>>> > On 6 Oct 2020, at 18:40, S E Geoscience and Exploration via SEGMIN < >>>> > [email protected]> wrote: >>>> > >>>> > Thanks. >>>> > >>>> > I prefer to call it "Amplitude Equalizer", sort of. >>>> > >>>> > On Tue, Oct 6, 2020 at 1:35 PM Richard Smith via SEGMIN < >>>> > [email protected]> wrote: >>>> > >>>> > Perhaps it is called tilt derivative as you have to calculate >>>> derivatives >>>> > to calculate it, as in the "tilt of the derivatives". Personally, I >>>> > prefer the term, "local phase" (Thurston and Smith, 1997), but I have >>>> a >>>> > conflict of interest! >>>> > >>>> > Regards >>>> > Richard Smith >>>> > >>>> > >>>> > >>>> > -----Original Message----- >>>> > From: S E Geoscience and Exploration via SEGMIN < >>>> [email protected]> >>>> > To: [email protected] >>>> > Cc: S E Geoscience and Exploration < >>>> > [email protected]> >>>> > Sent: Tue, Oct 6, 2020 11:29 am >>>> > Subject: [SEGMIN] Tilt is not a derivative >>>> > >>>> > Dear all, >>>> > >>>> > I am always so puzzled. Why do people call the Tilt in potential >>>> > techniques a derivative? It is not. >>>> > >>>> > Regards >>>> > >>>> > -- >>>> > *Sergio Espinosa, Ph.D., P.Geo* >>>> > Director, Geophysics >>>> > *S E G*eoscience & *Ex*ploration >>>> > ----------------------- >>>> > SEGMIN community mailing list service ([email protected]). >>>> > Change your personal options here: >>>> > https://lists.geosoft.com/mailman/options/segmin/geofizzics%40aol.com >>>> > Colleagues can join here: >>>> > https://lists.geosoft.com/mailman/listinfo/segmin >>>> > Archives: https://lists.geosoft.com/mailman/private/segmin/ >>>> > NOTE that <Reply> will reply to all members of the list. >>>> > ----------------------- >>>> > SEGMIN community mailing list service ([email protected]). >>>> > Change your personal options here: >>>> > >>>> https://lists.geosoft.com/mailman/options/segmin/se.geoscience.and.exploration%40gmail.com >>>> > Colleagues can join here: >>>> > https://lists.geosoft.com/mailman/listinfo/segmin >>>> > Archives: https://lists.geosoft.com/mailman/private/segmin/ >>>> > NOTE that <Reply> will reply to all members of the list. >>>> > >>>> > >>>> > >>>> > -- >>>> > *Sergio Espinosa, Ph.D., P.Geo* >>>> > Director, Geophysics >>>> > *S E G*eoscience & *Ex*ploration >>>> > ----------------------- >>>> > SEGMIN community mailing list service ([email protected]). >>>> > Change your personal options here: >>>> > >>>> https://lists.geosoft.com/mailman/options/segmin/alan%40reid-geophys.co.uk >>>> > Colleagues can join here: >>>> > https://lists.geosoft.com/mailman/listinfo/segmin >>>> > Archives: https://lists.geosoft.com/mailman/private/segmin/ >>>> > NOTE that <Reply> will reply to all members of the list. >>>> > >>>> > >>>> > Alan B Reid PhD >>>> > Reid Geophysics Ltd >>>> > 7 Keymer House >>>> > Michel Grove >>>> > Eastbourne BN21 1JZ >>>> > UK >>>> > >>>> > Phone: +44 (0) 1323 735520 >>>> > Mobile: +44 (0) 781 692 4728 >>>> > Skype Name: alanbarryreid >>>> > mailto: [email protected] >>>> > web: http://www.reid-geophys.co.uk >>>> > >>>> > >>>> > ----------------------- >>>> > SEGMIN community mailing list service ([email protected]). >>>> > Change your personal options here: >>>> > >>>> https://lists.geosoft.com/mailman/options/segmin/se.geoscience.and.exploration%40gmail.com >>>> > Colleagues can join here: >>>> > https://lists.geosoft.com/mailman/listinfo/segmin >>>> > Archives: https://lists.geosoft.com/mailman/private/segmin/ >>>> > NOTE that <Reply> will reply to all members of the list. >>>> > >>>> > >>>> > >>>> > -- >>>> > *Sergio Espinosa, Ph.D., P.Geo* >>>> > Director, Geophysics >>>> > *S E G*eoscience & *Ex*ploration >>>> > ----------------------- >>>> > SEGMIN community mailing list service ([email protected]). >>>> > Change your personal options here: >>>> > >>>> https://lists.geosoft.com/mailman/options/segmin/se.geoscience.and.exploration%40gmail.com >>>> > Colleagues can join here: >>>> > https://lists.geosoft.com/mailman/listinfo/segmin >>>> > Archives: https://lists.geosoft.com/mailman/private/segmin/ >>>> > NOTE that <Reply> will reply to all members of the list. >>>> > >>>> >>>> >>>> -- >>>> *Sergio Espinosa, Ph.D., P.Geo* >>>> Director, Geophysics >>>> *S E G*eoscience & *Ex*ploration >>>> -------------- next part -------------- >>>> An HTML attachment was scrubbed... >>>> URL: < >>>> https://lists.geosoft.com/mailman/private/segmin/attachments/20201007/8f9ad706/attachment-0001.htm >>>> > >>>> >>>> ------------------------------ >>>> >>>> Subject: Digest Footer >>>> >>>> ----------------------- >>>> SEGMIN community mailing list service ([email protected]). >>>> Change your personal options here: %(user_optionsurl)s >>>> Colleagues can join here: >>>> https://lists.geosoft.com/mailman/listinfo/segmin >>>> Archives: https://lists.geosoft.com/mailman/private/segmin/ >>>> NOTE that <Reply> will reply to all members of the list. >>>> >>>> >>>> ------------------------------ >>>> >>>> End of SEGMIN Digest, Vol 28, Issue 8 >>>> ************************************* >>>> >>> ----------------------- >>> SEGMIN community mailing list service ([email protected]). >>> Change your personal options here: >>> https://lists.geosoft.com/mailman/options/segmin/se.geoscience.and.exploration%40gmail.com >>> Colleagues can join here: >>> https://lists.geosoft.com/mailman/listinfo/segmin >>> Archives: https://lists.geosoft.com/mailman/private/segmin/ >>> NOTE that <Reply> will reply to all members of the list. >>> >> >> >> -- >> *Sergio Espinosa, Ph.D., P.Geo* >> Director, Geophysics >> *S E G*eoscience & *Ex*ploration >> > > > -- > *Sergio Espinosa, Ph.D., P.Geo* > Director, Geophysics > *S E G*eoscience & *Ex*ploration > ----------------------- > SEGMIN community mailing list service ([email protected]). > Change your personal options here: > https://lists.geosoft.com/mailman/options/segmin/ed.cunion%40gmail.com > Colleagues can join here: > https://lists.geosoft.com/mailman/listinfo/segmin > Archives: https://lists.geosoft.com/mailman/private/segmin/ > NOTE that <Reply> will reply to all members of the list. > <https://www.avast.com/sig-email?utm_medium=email&utm_source=link&utm_campaign=sig-email&utm_content=webmail&utm_term=icon> Virus-free. www.avast.com <https://www.avast.com/sig-email?utm_medium=email&utm_source=link&utm_campaign=sig-email&utm_content=webmail&utm_term=link> <#DAB4FAD8-2DD7-40BB-A1B8-4E2AA1F9FDF2>
----------------------- SEGMIN community mailing list service ([email protected]). Change your personal options here: https://lists.geosoft.com/mailman/options/segmin/archive%40mail-archive.com Colleagues can join here: https://lists.geosoft.com/mailman/listinfo/segmin Archives: https://lists.geosoft.com/mailman/private/segmin/ NOTE that <Reply> will reply to all members of the list.
