西藏蛇绿岩中不寻常的地幔矿物群  

An unusual mantle mineral group in ophiolites of Tibet

作　　者：白文吉[1] 杨经绥[1] 方青松[1] 颜秉刚[1] 史仁灯[1] 

机构地区：[1]中国地质科学院地质研究所,北京100037

出　　处：《中国地质》2003年第2期144-150,共7页Geology in China

基　　金：国家自然科学基金项目(49972073)

摘　　要：在西藏雅鲁藏布江蛇绿岩的铬铁矿中,首次发现由100余种(亚种)矿物组成的地幔矿物群,其中包括:自然元素、合金、氧化物、硫(砷)化物和硅酸盐。根据实验资料,其中一部分是超高压成因矿物,可能来自地球核-幔边界,是地球外核与下地幔底部硅酸盐之间化学反应的产物,另一部分矿物可能来自下地幔、过渡带和上地幔。西藏地幔矿物群,无论在矿物学和地球动力学上均有重要意义。An unusual mantle mineral group consisting of more than100species(or subsp ecies)minerals was dis-covered in chromite from the Yarlung Zangbo ophiolite belt,Tibet.It includes native element minerals,alloys,oxides(arsenides)and silicates.According to expe rimental data,some of the minerals are ultrahigh-pressure min-erals,possibly formed at the Earth' s core-mantle boundary,and are the produ cts of chemical reactions between liquid iron of the Earth' s outer core and sil icates at the base of the lower mantle ;others might be derived from the lower mantle,transitional zone and upper mantle.The mantle mineral group in Tibet has great significance in mineralogy an d geodynamics.

关 键 词：西藏 蛇绿岩 铬铁矿 地幔矿物群 地球动力学 矿物学 超高压矿物 

分 类 号：P618.2[天文地球—矿床学]