Norbert, Thanx for correction as always.
This does answer reinforce the Mars material late arrival notion? Still too complicated is a start... Time, time, time... JD > Hi Mark, John, and List, > > Since Eric already addressed an error in the first answer regarding > the absolute ages of Martian, and lunar meteorites, let me address an > error in the second answer: > > > Q: How long have these planetary meteorites been on earth? > > A: Probably all less than 25,000 years. So we know the rate of finds > > from material found that probably fell in recent times. 1 to 1 > > Humm, this isn't true, at least not for several lunar meteorites > in our collections. More recent studies show that some lunaites > exhibit remarkably long terrestrial residence ages. For example, > the terrestrial age for the lunar breccia Dhofar 025 (and pairings, > e.g., Dho 301, 304, and 308) is estimated at 500ka (yes, that's > 500,000 or half-a-million years!). Some Antarctic finds are also > much, much older than 25ka, such as MAC 88104/88105 that shows a > terrestrial age of about 200ka. In fact, most lunaites have > terrestrial ages of 10ka (10,000 years) or more, and only a few > are thought to have fallen in more or less recent times. > > I'm not sure regarding the Martian meteorites of which at least > four represent witnessed falls - a fact that raises even more > questions... > > All the best, > Norbert ______________________________________________ Meteorite-list mailing list [EMAIL PROTECTED] http://www.pairlist.net/mailman/listinfo/meteorite-list
