岩石矿物学杂志2001，Vol.20Issue(1)：1-10,10.
西藏罗布莎蛇绿岩豆荚状铬铁矿中镁橄榄石的晶体结构及其意义
Crystal Structure of Forsterite from Podiform Chromitite in Luobusa Ophiolite of Tibet And Its Implications
摘要
Abstract
The forsterite mineral inclusions in chromite of podiformchromitite occur in mantle peridotite of Luobusa ophiolite in the Indo_Yarlung Zangbo tectonic unit. The forsterite inclusions from chromite grains have Fo number of 97～99 and assume the form of colorless, transparent and euhedral grains with abundant small faces. The crystal of forsterite used for X_ray analysis was measured to be approximately 0.15 mm×0.15 mm×0.15 mm. Crystal system of this forsterite is orthorhombic, space group Pbnm, α, β and γ is 90°, a=4.7597Å, b=10.205Å, c=5.9831Å. The unit cell parameters of forsterite, a, b, c as well as M1—O and M2—O bond lengths are smaller than those of some olivines from mantle xenolith and mantle peridotites. The unit cell parameters of the forsterite in the study area are the same as those of the synthetic forsterite. According to experimental study cited in the literature, the small unit cell andcation_oxygen bond distances of olivine suggest a high pressure of its crystallization.关键词
晶体结构/镁橄榄石/豆荚状铬铁矿/西藏分类
天文与地球科学引用本文复制引用
白文吉,方青松,张仲明,颜秉刚,杨经绥..西藏罗布莎蛇绿岩豆荚状铬铁矿中镁橄榄石的晶体结构及其意义[J].岩石矿物学杂志,2001,20(1):1-10,10.基金项目
本文系国家自然科学基金项目的部分成果 （）
