新疆阿尔泰铁木里克花岗闪长岩锆石U-Pb年龄及地质意义

Zircon U-Pb Dating and Geological Significance of Granodiorite in Tiemulik,Altay,Xinjiang

通过对新疆阿尔泰南缘富蕴-蒙库成矿带中铁木里克铁矿矿区出露的花岗闪长岩进行了锆石SHRIMP U-Pb年龄测定,获得岩体形成时代为(389±5.7)Ma(MSDW=1.7)。该岩体是早泥盆世岩浆活动产物,属海西早期侵入体。岩体侵入活动伴随铁矿成矿作用,表明铁木里克铁矿的形成时代略晚于389 Ma。前人研究表明,阿尔泰造山带早泥盆世时期岩浆活动异常强烈,400-360 Ma是主造山期。铁木里克岩体的形成处于阿尔泰造山作用最强时期。对比铁木里克岩体与蒙库岩体的形成时代及空间产出,认为铁木里克岩体形成于与板块俯冲有关的活动大陆边缘的陆弧环境。

This paper reports zircon U-Pb dating result for granodiorite located at Tiemulik iron ore deposit of Fuyun-Mengku metallogenic belt in southern Altay, Xinjiang.This granodiorite,yield ages of （389±5.7） Ma（MSDW=1.7）. The granodiorite are formed during Early Devonian magmatic activity,belongs to the Early Hercynian intrusive body rather than the Late Hercynian.The intrusion activities along with the mineralization of iron ore,which indicates that the formation age of Tiemulik iron ore later than 389 Ma.Previous studies have shown that there are a magmatic cativity peak in Altay orogen during the Early Devonian,400-360 Ma was the main orogenic period,the granodiorite of Tiemulik was formed during the strongest period of Altay orogeny.Tiemulik pluton is also formed in the continental arc environment after compared the era of Tiemulik pluton and Mengku pluton.