摘要
在西藏雅鲁藏布江蛇绿岩带的东部,距拉萨市200 km 的罗布莎蛇绿岩的豆荚状铬铁岩中,发现方铁矿和自然铁。而且以自然铁为核心并包裹于方铁矿中,两者形成圆球形态。自然铁的空间群为 Fm3m,晶胞参数α=0.28663 nm。方铁矿空间群为 Fm3m,晶胞参数α=0.43070 nm。根据有关实验资料推断,高压矿物方铁矿和自然铁来自下地幔,并且可能为核幔边界化学反应生成物。
Wustite and native iron have been first discovered from podiform chromitite ore bodies in the ophiolite at Luobusa, eastern part of the Yarlung Zangbo River, about 200 km southeast of Lhasa. The grains of native iron are in globular form rimmed by wustite. The two minerals have been analyzed by the X-ray diffraction and energy dispersion spectrometry methods. The space group of the native iron is Fm3m, and that of wustite is Fm3m too, with a = 0. 28663 nm and 0. 43070 nm respectively. Based on high-pressure and high-temperature experimental data, this assemblage was formed in the lower mantle as a result of the reaction between the Earth's outer core and lower mantle, and then brought up to the upper mantle by the plume.
出处
《地质论评》
CAS
CSCD
北大核心
2004年第2期184-188,共5页
Geological Review
关键词
方铁矿
自然铁
下地幔
超高压矿物
西藏
蛇绿岩
wustite
native iron
lower mantle
ultrahigh-pressure mineral
Xizang (Tibet)
