阿尔金南段岔沟泉花岗岩体锆石U⁃Pb定年及构造演化特征

Zircon U⁃Pb dating and tectonic evolution of the Chagouquan granitic bodyin the southern Altun section

由于阿尔金造山作用,促使地壳重熔形成了大量的花岗岩体。本文以岔沟泉花岗岩体为研究对象,通过锆石测年、岩石地球化学研究等方法,认为该岩体形成于泥盆纪,物质主要来源于地壳,属碱钙性系列岩石,岩石地球化学特征与岛弧岩石地球化学特征相似,表明该岩体可能形成于同碰撞期→造山晚期后的火山岩浆弧构造环境。对研究阿尔金造山带的构造演化具有指导意义。

Due to Altun orogeny,the crust was remelted to form a large number of granite rocks.Based on Chagouquan granite rock mass as the research object,through the methods including zircon dating and rock geochemistry research,this paper considered that the rock mass formed in the Devonian,whose material mainly came from the earth′s crust,belonging to calcium alkali series rock.Rock geochemical characteristics was similar to arc rock geochemical characteristics,which meant that the rock mass may be formed in the volcanic magma arc tectonic environment from the collision period to the late orogenesis.It is of guiding significance to study the tectonic evolution of altun orogenic belt.