【摘要】 <正> 西乌珠穆沁陨石(简称西乌陨石)和渑池陨石是1980年8月和9月分别陨落在我国内蒙古西乌珠穆沁旗和河南省渑池县的两块球粒陨石,现收藏于北京天文馆。两陨石新鲜断面都为灰色,肉眼均能见到球粒。陨落情况及陨石外部特征已有报道,在此不一一赘述。 一、矿物组成及特征 表1列出两陨石的标准矿物百分含量由化学全分析结果计算而得,方法见文献。两陨石矿物成分比较,西乌陨石含硅酸盐较高(主要是橄榄石的含量高造成的),而金属铁镍更多还原

【Abstract】 The Xi Ujumqin meteorite fell in Aug. 1980 at Xi Ujumqin County, Nei Monggol, China.This chondrite can be classified as L₆ type based on the bulk chemical analysis （6wt% metal iron, 24% total iron, olivine Fa-26） and the textural feature of complete intergrowth of the chondrules with the matrix.The Mianchi meteorite is a type H₅ chondrite that fell in Sep. 1980 at Mianchi County, Henan, China. Apart from porphyritic, barred, radial, cryptocrystalline chondrules, many intermediate-type or mixed-type chondrules are observed in the Mianchi meteorite under the microscope. It is suggested that the origin of chondrules showing different textures depend on the primeval compositions and cooling rates.更多还原