极地研究

极地研究 ›› 2009, Vol. 20 ›› Issue (2-English): 187-199.

• 研究论文 • 上一篇    下一篇

Shock metamorphism of ordinary chondrites from Grove Mountains, Antarctica

 Feng Lu1, Lin Yangting1, Hu Sen1 and Liu Tao2   

  1. 1 Institute of Geology and Geophysics, Chinese Academy of Science, Beijing 100029, China;
    2 Guangzhou Institute of Geochemistry, Chinese Academy of Science, Guangzhou 510640, China
  • 出版日期:1959-06-30 发布日期:1959-06-30
  • 通讯作者: Feng Lu

Shock metamorphism of ordinary chondrites from Grove Mountains, Antarctica

 Feng Lu1, Lin Yangting1, Hu Sen1 and Liu Tao2   

  1. 1 Institute of Geology and Geophysics, Chinese Academy of Science, Beijing 100029, China;
    2 Guangzhou Institute of Geochemistry, Chinese Academy of Science, Guangzhou 510640, China
  • Online:1959-06-30 Published:1959-06-30
  • Contact: Feng Lu

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摘要：

Shock effects of 93 Grove Mountains ( GRV ) ordinary chondrites were studied in this work, including fracture, various types of extinction, and recrystallization of silicates observed under optical microscopy. Shock-induced veins and pockets how various microtextures, decomposition and phase transformation of minerals. The on firmed high-pressure polymorphs of silicates are ringwoodite, majorite, pyroxene lass and maskelynite. Based on the shock effects and assemblages of h igh-pressure  inerals, shock stages of all of 93 GRV chondrites were classified. In comparison with literature, the Grove Mountains meteorites have a higher fraction ( 23 out of 93) if heavily shocked samples ( S4-S5). Most of the heavily shocked meteorites are L group ( 22 out of 23), except for one H chondrite. The distinct shock metamorphism between H and L groups may indicate different surface properties of their parent bodies. In add ition, there is rela tionship between petrologic types and shock stages, with most heavily shocked samples observed in equilibrated ordinary chondrites ( especially Type 5 and 6).

关键词: Antarctic, Grove Mountains, chondrites, shock metamorphism, high-pressurem ineral

Abstract:

Shock effects of 93 Grove Mountains ( GRV ) ordinary chondrites were studied in this work, including fracture, various types of extinction, and recrystallization of silicates observed under optical microscopy. Shock-induced veins and pockets how various microtextures, decomposition and phase transformation of minerals. The on firmed high-pressure polymorphs of silicates are ringwoodite, majorite, pyroxene lass and maskelynite. Based on the shock effects and assemblages of h igh-pressure  inerals, shock stages of all of 93 GRV chondrites were classified. In comparison with literature, the Grove Mountains meteorites have a higher fraction ( 23 out of 93) if heavily shocked samples ( S4-S5). Most of the heavily shocked meteorites are L group ( 22 out of 23), except for one H chondrite. The distinct shock metamorphism between H and L groups may indicate different surface properties of their parent bodies. In add ition, there is rela tionship between petrologic types and shock stages, with most heavily shocked samples observed in equilibrated ordinary chondrites ( especially Type 5 and 6).

Key words: Antarctic, Grove Mountains, chondrites, shock metamorphism, high-pressurem ineral