摘要
Ureilites share the characteristics of differentiated meteorites and of primary chondrites. GRV 024237 is a ureilite, which was found in the 19th Chinese National Antarctic Research Expedition （CHINARE）, at the No. 4 moraine, Grove Moun- tains, Antarctica. GRV 024237 consists mainly of coarse-grained olivine （60 vol%）, pigeonite （30 vol%） and opaque minerals （10 vol% ）. Tri-junction texture between olivine and pigeonite is common. Carbonaceous materials with minor amounts of troilite and nickel-iron metal were observed as interstitial phases. The Fa value of olivine composition varies from 6.2 to 16.8 from rim to core, but pyroxene is homogeneous in composition, with Fs 14.0 to 15.5. Both olivine and pyroxene have normal extinctions. Net-like iron or limonite veins filled in the fractures of olivine and pyroxene, and no diamond was observed. Based on petrographic and mineralogical features, GRV 024237 is a Type I and Group 2 monomict ureilite.
Ureilites share the characteristics of differentiated meteorites and of primary chondrites. GRV 024237 is a ureilite, which was found in the 19th Chinese National Antarctic Research Expedition （CHINARE）, at the No. 4 moraine, Grove Moun- tains, Antarctica. GRV 024237 consists mainly of coarse-grained olivine （60 vol%）, pigeonite （30 vol%） and opaque minerals （10 vol% ）. Tri-junction texture between olivine and pigeonite is common. Carbonaceous materials with minor amounts of troilite and nickel-iron metal were observed as interstitial phases. The Fa value of olivine composition varies from 6.2 to 16.8 from rim to core, but pyroxene is homogeneous in composition, with Fs 14.0 to 15.5. Both olivine and pyroxene have normal extinctions. Net-like iron or limonite veins filled in the fractures of olivine and pyroxene, and no diamond was observed. Based on petrographic and mineralogical features, GRV 024237 is a Type I and Group 2 monomict ureilite.
基金
supported by the Pilot Project of Knowledge Innovation Program of the Chinese Academy of Sciences (Grant no.kzcx2-yw-Q08)
the National Natural Science Foundation of China (Grant no.40873054)
the China Program for International Polar Year 2007-2008
the Polar Research Strategic Research Foundation of China (Grant no.20100208)
