摘要
传统研究将新疆天山干沟段博罗科努带花岗岩划为石炭纪或泥盆纪,中天山花岗片麻岩划为加里东期.本文根据1:5万区调成果,将其分别厘定为志留纪和前寒武纪.论证了志留纪干沟序列花岗岩构造环境.其序列组成为石英闪长岩-花岗闪长岩/斜长花岗岩/英云闪长岩-二长花岗岩组合,二长花岗岩略多,地球化学特征具典型造山花岗岩特征,K-Na-Ca图解中性段具英云闪长岩趋势,酸性段呈钙碱性趋势,其构造环境为大陆弧.据花岗岩中的斜长石内高岭土和绢云母结晶形态,辨识出研究区志留纪干沟序列花岗岩具绿片岩相变质.
In the previous data, granite in the Boluokenu belt of Gangou in Xinjiang is thought to be Carboniferous or Devonian and granite-gneiss in Middle Tianshan Mountain is Caledonian.Based on the results of regional survey at 1：50000,authors think this granite is Silurian and this granite-gneiss is Precambrian. This paper has demonstrated the tectonic setting of Silurian granite in Gangou sequence,which constitutes the assemblage of quartz diorite-granite diorite/plagioclase granite/toellite diorite- adamellite with more adamellite. Its geochemical feature belongs to the typical orogenic granite. In the K-Na-Ca diagram, intermediate part has the tendency of toellite, and acid part has the tendency of calc-alkaline. According to the above data, its tectonic setting is thought to be continental arc. Based on the crystal shape of kaoline and sericite in plagioclase of granite,it is determined that Silurian granite in Gangou sequence has greenschist facies.
出处
《新疆地质》
CAS
CSCD
北大核心
2009年第4期308-314,共7页
Xinjiang Geology
关键词
博罗科努
中天山
花岗岩
志留纪
大陆弧
干沟
Granite
Silurian
Continent arc
Gangou
Middle Tianshan Mountain
Boluokenu
Xinjiang
