南极格罗夫山H群普通球粒陨石冲击变质特征

本文研究了47块格罗夫山H群普通球粒陨石冲击变质效应。在光学显微镜下对陨石中硅酸盐矿物和不透明矿物的冲击变质效应，其中包括波状消光、破裂、马赛克消光、冲击熔融和金属硫化物枝状共晶进行了观察。利用扫描电镜对10块H群普通球粒陨石的不透明冲击熔脉进行观察与分析，在GRV022469冲击熔脉中发现了瓦茨利石。GRV022469成为我国第一块发现高压相矿物的南极H群普通球粒陨石。瓦茨利石的岩石矿物学特征表明它形成于固态相变机制。根据冲击变质效应，特别是冲击熔脉中矿物结构及成分，分析得出H群普通球粒陨石的冲击变质特征：H群普通球粒陨石冲击变质程度普遍偏低（低于S5），陨石中冲击熔脉宽度较窄，脉体中矿物组合为常压相矿物。

SHOCK METAMORPHISM OF H-CHONDRITES FROM THE GROVE MOUNTAINS, ANTARCTICA

Shock metamorphism of 47 H-Chondrites from Grove Mountains(GRV), Antarctica, were studied. Silicate and opaque minerals were observed under optical microscope for shock metamorphism features, such as undulatory extinction, planar fractures, mosaic extinction, shock-induced melting, and metal-sulfide dendritic eutectic. Shock-induced regions of 10 H-Chondrites were observed. Wadsleyite was found in GRV022469. Petrologic and mineralogical characteristics support that wadsleyite was formed by solid-state transformation. Based on shock effects, especially low-pressure phase mineral components and chemical characteristic, shock metamorphism stage of H-Chondrites is relatively low (lower than the S5). Shock-induced melt veins are thinner compared to those in L-Chondrites.