东昆仑祁漫塔格伊涅克阿干花岗岩特征及构造意义

The Yinieke’agan granite mass in Qimantag,eastern Kunlun and its tectonic significance

摘要: 伊涅克阿干花岗岩是含白云母过铝质花岗岩,由二长花岗岩—钾长花岗岩分3次侵入组成的复式岩体。岩石呈灰白色,富含钾长石和钠-更长石,普遍含原生白云母,富含浅源捕虏体和残留体;A/CNK=0.99～1.34;ISr=0.71199,Rb-Sr全岩等时线年龄为435.7 Ma,是早古生代柴达木板块与塔里木板块碰撞导致地壳加厚,并在地幔热流注入参与作用下,地壳深部发生熔融作用形成花岗岩浆侵位形成的同碰撞花岗岩。

Abstract: The Yinieke’agan granite mass consists of muscovite-bearing peraluminous granites occurring as a compound mass composed of adamellite and moyite.The mass is grayish white and contains potassic feldspar, albite,oligoclase,primary muscovite,epixenoliths and relicts.A/CNK=0.99-1.34,with a mean value of 1.097.ISr=0.71199.The whole-rock Rb-Sr isochron age is 435.7 Ma.This granite mass is interpreted as a kind of syncollisional granites resulted from the crustal thickening caused by the collision between the Qaidam plate and Tarim plate during the Early Palaeozoic and melting giving rise to three phases of emplacement of the granitic magmas influenced by the mantle thermal plumes.