Hello Bernd and list, Glad to see that my question has drawn some discussion and especially happy to see Bernd answered. I'm not suprised to see wide ranges of fayalite within type 3 chondrites as those have not been homogenized and it would actually be expected that some rather extreme values listed. The one meteorite you mentioned that got my attention were the ones that are a type 4 or above. I'm wondering if you have any other information on the pyroxene and metal values of some of these. Thanks, Rhett Bourland www.asteroidmodels.com www.asteroidmodels.com/personal www.meteoritecollectors.org
-----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]]On Behalf Of Bernd Pauli HD Sent: Friday, July 12, 2002 2:10 PM To: [EMAIL PROTECTED] Cc: [EMAIL PROTECTED]; Meteorite List Subject: [meteorite-list] Meteorite Question Rhett Bourland wrote: > On the lower end of the H chondrite values there is a very > small bar on 15%. I was wondering if you could possibly tell > me how many meteorites are represented by that bar and if > there aren't too many which ones are they? Hello Rhett and Fayalists :-) In the lower left corner of that graph you find my name and the date when this graph was generated: October 23, 1994 so I think that the 4th edition of the Meteorite Catalogue, the Big Blue Book, was the basis for this graph. Presently there are six H chondrites with fayalite values ranging from 15 to 16 % fayalite. These include the following: Name Class Fell/Find Year Fa Xinyi H5 Find 1975 15 Willaroy H3 Find 1970 15 Grady (1937)H3.6 Find 1937 15 Burnwell H Fell 1990 15,8 DaG 385 H3-4 Find 1997 15,9 Clipperton H3 Find 1986 15,9 The 1994 graph shows Xinyi, Willaroy, and Grady (1937). > Dr. McCoy at the Smithsonian was talking about that meteorite > having a Fa content of 15.8 +/- .2% and stated that the average > Fa composition of H chondrites is only between 16.9-20.4%. > Obviously there will be some meteorites within that class that > are slightly above or below average so I was wondering about the > ones that are a bit lower than that and any possible relationships > they may have to Burnwell. Well, meanwhile there are actually H chondrites with even lower Fa values in my databases: Name Class Fell/Find Year Fa C.los Calvos H4 Find 1986 12,5 Suwahib H3.7 Find 1931 14,4 DaG 862 H3 Find 1999 14,4 As for the US Antarctic H chondrites, I have the following: NAME DESIG FA FRO 95038 H4 14.7 FRO 95014 H4 14.8 ALH 77221 H4 15 EET 87553 H4 15 EET 87808 H4 15 ALH 84105 H6 15 EET 96037 H4 15 EET 96047 H4 15 GRV 99025 H5 15.6 This overview does not include ones with variable Fa values or ranges, especially the unequilibrated specimens. Some examples so that you know what I am talking about: NAME DESIG FA GRA 98087 H3.8 01-19 LEW 88500 H3.7 01-20 WSG 95300 H3.3 01-21 LEW 88315 H3.5 01-22 > the average Fa composition of H chondrites > is only between 16.9-20.4% ... As for the upper value of 20.4% fayalite, there are also some "exceptions to the rule": Name Class Fa DaG 536 H6 21 Cleo Springs H4 21 Oakley (stone) H6 21 Forrest 031 H4 21 Menindee L. 002 H5 21,1 Glenrothes H5 21,4 Acfer 316 H6 21,4 Dhofar 063 H5 21,4 Oviedo H5 25 US Antarctica: FRO 90081 H6 21.4 FRO 90131 H4 21.2 Best wishes, Bernd ______________________________________________ Meteorite-list mailing list [EMAIL PROTECTED] http://www.pairlist.net/mailman/listinfo/meteorite-list ______________________________________________ Meteorite-list mailing list [EMAIL PROTECTED] http://www.pairlist.net/mailman/listinfo/meteorite-list
