Grove Mountains 99027


                    THE METEORITICAL BULLETIN
                 Announcement 86-1, April 5, 2002
               Sara Russell, Editor (sara.russell@nhm.ac.uk)
          Jutta Zipfel, Assoc. Ed. for Saharan Meteorites 
                  (zipfel@mpch-mainz.mpg.de)
    Jeffrey N. Grossman, Assoc. Ed. for Web (jgrossman@usgs.gov)
                 Monica M. Grady, Co-Editor 

Grove Mountains (GRV) 99027         73006'01" S, 75014'13" E
  Antarctica
  Found 2000 February 8
  Martian meteorite (lherzolitic shergottite)
This meteorite weighs 9.97 g, and most of the surface is covered by 
fusion crust. Classification and Mineralogy (Lin and B. Miao, GIG;  
H. Wang & C. Lin, NU): It is composed mainly of coarse-grained 
orthopyroxene, olivine, clinopyroxene and plagioclase, with minor 
opaque  minerals. There are two textures. In the larger part of the 
sections, olivine occurs as rounded euhedral grains, poikilitically 
enclosed  in a megacryst of orthopyroxene; in the other side of the 
sections, it shows a cumulate texture, consisting of euhedral 
orthopyroxene,  clinopyroxene, olivine and interstitial plagioclase. 
Chromite, the most common opaque phase, is euhedral and enclosed in 
pyroxenes. The  mineral assemblage and textures are similar to the 
Allan Hills (ALHA) 77005 lherzolite. The FeO/MnO (wt%)  ratio of 
orthopyroxene is  34+/-5. Compositions of orthopyroxene (En66-78Fs20-
26Wo2-8), clinopyroxene (En48-52Fs13-15Wo34-39), olivine (Fa22-30) 
and plagioclase  (An49-55Ab44-50Or<1) overlap with the ranges in 
ALHA77005. Fracturing and undulose extinction in silicates are  
strong. Plagioclase is  commonly deformed, and partially turns into 
maskelynite along the boundaries of grains. The shock stage is S4; 
weathering grade, W1. The  meteorite is curated at PRIC.