摘要
环斑花岗岩是发育于前寒武纪的一种特殊岩石。本文从环斑花岗岩的地质学、岩石学及矿物学等方面讨论了宽甸元古宙环斑花岗岩的成因,认为环斑花岗岩是由分异出石英二长岩的富钾质残余岩浆在深部同化围岩(类似盖县组的矽线石榴黑云斜长片麻岩及黑云母变粒岩等岩石)形成的含大量围岩捕虏晶的晶粥状岩浆,经侵位结晶而成。环斑长石的斜长石外壳是来自围岩的捕虏晶,它通过流动、吸附作用附着于钾长石巨晶的周围,构成环斑结构。
Rapakivi is a special rock in Precambrian. This paper has disscussed thegenesis of Proterozoic rapakivi in Kuandian, Liaoning Province of China,ingeology, petrology and mineralogy. We concluded that the rapakivi wasformed by intrusion and crystallization of the crystal-mush magma whichcontained a lot of xenocryst of country rocks Sill-Ga-Bi-Pl-gneisses and Bi-leptynite etc-- The magma was formed by assimilation between a K-richrelict magma of adamellite and its country rock in deepth.The plagioclaseoutercrust of rapakivi feldspar was derived from xenocryst of countryrocks. It surrounded the K-feldspar by flowing and absorption and thusthe rapakivi texture was formed.
关键词
花岗岩
环斑花岗岩
宽甸
混染
Kuandian, rapakivi, assimilation and cnotamination, flowing and absorption
