攀西裂谷带中白马杂岩及其单矿物的稀土元素地球化学特征  

REE GEOCHEMISTRY OF BAIMA COMPLEX IN THE PANXI RIFT BELT

作　　者：杨瑞瑛[1] 许文良 刘若新[3] 

机构地区：[1]中国科学院高能物理研究所 [2]中国科学院核分析技术开放研究实验室,北京,100080 [3]国家地震局地质研究所

出　　处：《矿物学报》1997年第1期71-77,共7页Acta Mineralogica Sinica

摘　　要：稀土元素及锶同位素资料表明，形成白马杂岩体的母岩浆为玄武质岩浆，起源于上地幔，由被交代的上地慢橄榄岩经5％～10％部分熔融形成的；层状侵入体和正长岩为同源岩浆演化的产物；做榄石、单斜辉石和斜长石是岩浆演化早期最重要的堆积矿物；产于细粒辉长岩和层状辉长岩中的单斜辉石和斜方辉石，它们的Eu和Ce异常的差异，主要受控于矿物结晶时的氧化还原条件。REE and Sr isotope data suggest that the parental magma from which the Baima igneous complex crystallized is a basaltic magma. It secms to be derived from the metasomatized upper mantle by 5% ~10% partial meltlng. Layered intrusives and syenites wcre originated from comagmatism. Olivine,plagioclase and clinopyroxene are the important cumulative phases during the early stage of magmatic evolution. Eu and Ce anomalies in clinopyroxene and orthopyroxene from finegrained gabbro and bcdded gabbro could be attributed to the oxidation and reduction conditions during the crystallization of the minerals.

关 键 词：裂谷 辉长岩 杂岩 单矿物 稀土族 地球化学 

分 类 号：P588.36[天文地球—岩石学] P578.14[天文地球—地质学]