Abstract:

Meteorite samples can be better preserved in Antarctic ice sheet and arid desert regions. Fortyseven desert meteorites were collected from Xinjiang during the meteorite expedition since April to May, 2013. Petrography and mineral chemistry of the 6 samples of them have been studied, in order to determine their chemicalpetrographic types. Modal compositions of the Arlatager 004, 006, 0014, 0022 and TuzLeik001 meteorites are similar, mainly consisting of olivine, lowCa pyroxene, metallic FeNi and troilite. Due to intensive thermal metamorphism the spherulitic textures in the chondrules are poorly defined, with only a few fragments remaining spherulitic. The olivine and lowCa pyroxene in these meteorites are similar in composition, which in some degree reflects the thermodynamic equilibrium during their development. According to the structures of chondrules and mineral chemistry there are 5 petrographic types to be classified. The four meteorite samples (Arlatager 004, 006, 0014 and 0022) are classified into chemical group L, and TuzLeik001 is classified into chemical group H. Kumtag005 meteorite sample shows typical spherulitic texture, combined with its Fa value in olivine and ferrosilite content (Fs) in low Ca pyroxene and its petrographical features,it is assigned to common chondrite of L3 type.Based on Percent Mean Deviation (PMD) of Fa content of olivine and its correction with petrographic subtype of unequilibrated meteorites, Kumtag005 is subdivided as L3.4. The 6 samples of meteorites belong to 3 chemical groups, combining  the other analytical results of meteorites collected from this region, it is suggested that the desert of Hami in Xinjiang is likely a new meteoriteenriched region. The collection and study of desert meteorite will help to promote the development of meteoritics and cosmochemistry in China.

Key words: desert meteorite, petrography, mineral chemistry, classification, Xinjiang