南极GRV 99027陨石:火星陨石中的一个新成员

来自南极格罗夫山蓝冰地区的GRV 99027陨石为一无球粒陨石,主要由橄榄石及辉石组成。棕色橄榄石具堆晶结构及镶嵌结构等火成岩浆分异结晶的特征。陨石的矿物模式组成及化学成分显示与SNC族陨石特征相似,特别是与ALHA77005陨石十分接近。后者被确定为二辉橄榄岩质辉玻无球粒陨石类(Lherozolitic-Shergotty,L-S)火星陨石。GRV 99027陨石的矿物化学特征以及FeO/MnO比值也与L-S类相似。可以初步认为GRV 99027陨石为SNC族火星陨石一个新的成员。二辉橄榄岩相当于地球的上地幔成分。陨石来自火星探部,为世界上极为稀有的火星样品,极具研究价值。

ANTARCTIC GRV 99027 METEORITE: A NEW MEMBER IN MARTIAN METEORITE

GRV 99027 meteorite from Blue Ice Area in Antarctica is an achondrite. It consists predominantly of olivine and pyroxene. Both cumulate texture and poikilitic texture can be seen in this achondrite. These textures are peculiar to fractional crystallization of magma. The modal mineralogical composition and chemical compositions for GRV 99027 meteorite are similar to those of SNC meteorites and especially approach to ALHA 77005 meteorite. The latter has been ascertained to be a Martain meteorite of Lherozolitic-Shergotty type ( L-S type). Its mineral chemical chracteristics and FeO/MnO ratio are also similar to those of L-S type. Based on above - mentioned the authors consider that GRV 99027 meteorite is tentatively a new member of SNC meteorite clan. It is reported that SNC meteorites may be from the Mars. Due to Lherozolites correspond to composition of the mantle in the Earth, the GRV 99027 meteorite could originally occur in the depths of the Mars. Therefore, the new achondrite provides a rare sample from other planetary in the solar system and has an important significance in study on the Mars. The sample we got is very small that the research work for the achondrite is preliminary merely. To draw final conclusion ascertained GRV99027 to be a Martain meteorite many work ( such as oxygen and inert gas composition analysis, radiometric isotopic age determination and some others) should be done.