金川铜、镍(含PGE)岩浆硫化物矿床母岩浆成分的估计

ESTIMATION FOR CHEMICAL COMPOSITION OF PARENT MAGMA OF JINCHUAN CU NI(PGE) MAGMATIC SULFIDE DEPOSIT

利用金川侵入体的岩石化学和铂族元素资料，根据Ｒｏｅｄｅｒ和Ｅｍｓｌｉｅ的橄榄石液相平衡原理，估计金川超镁铁质岩的母岩浆为大约含１０８％ＭｇＯ的高镁玄武岩浆；将其与不同构造背景下形成的玄武岩岩石化学成分进行对比，认为金川侵入体的母岩浆的化学成分与巴西北部Ｍａｒａｎｈａｏ低Ｔｉ玄武岩浆的化学成分相似，代表了一种大陆裂谷背景下火山活动的产物。

By using the analytical data of petrochemistry and PGE+Au of Jinchuan ultramafic rocks,it is estimated that the parent magma of Jinchuan ultramafic rocks is a high magnesian basaltic magma containing about 10 8%MgO on the basis of Roeder and Emislie olivine liquid equilibrium theory. Comparing with some basalts from different tectonic settings, the authors suggest that the chemical composition of the parent magma of Jinchuan intrusion is similar to that of low Ti basalt of Maranhao in northern Brazil,which represents the product of a volcanism under the continental rift environment.