准噶尔东北缘喀拉安-恰库尔特一带晚古生代火山岩地球化学特征及构造意义  

Gechemical Characteristics of Late Paleozoic Volcanic rocks in Kalaan-Qiakuerte Area,in Northeastern margin of Junggar, and its Tectonic Significant

作　　者：陈琪乐 黄剑[2] 

机构地区：[1]新疆维吾尔自治区地质调查院,新疆乌鲁木齐830000 [2]新疆大学,新疆乌鲁木齐830047

出　　处：《新疆地质》2016年第1期62-67,共6页Xinjiang Geology

基　　金：中国地质调查局项目(1212011140058);自治区区域地质矿产调查项目(XJQDZ200908)联合资助

摘　　要：准噶尔北缘喀拉安-恰库尔特一带晚古生代火山岩十分发育,泥盆系卓木巴斯套组为一套海相火山沉积体系钙碱性系列火山岩、石炭系巴塔玛依内山组为陆相火山喷发体系碱性系列火山岩、二叠系哈尔加乌组为陆相火山-沉积体系亚碱性系列的火山岩。卓木巴斯套组无明显的Ti负异常,加上其大离子亲石元素富集的特点,说明其为岛弧发展后期地壳增厚的产物;巴塔玛依内山组高场强元素的亏损,大离子亲石元素的富集,暗示了其典型的消减带特征,但其缺乏明显的Ce负异常,推测其为弧后盆地环境;据哈尔加乌组地球化学特征,强不相容元素的富集,Nb,Ta和Ti的负异常较明显,推测其产生在裂谷环境。本文在对研究区晚古生代火山岩地质、地球化学特征等研究基础上,判断研究区早泥盆世为俯冲阶段的岛弧环境,晚石炭世为弧后盆地环境,二叠纪为造山后的拉张环境。Late Paleozoic volcanic rocks are developed in Kalaan-Qiakuerte area of Northeastern margin of Junggar.Lower Devonian Zhuomubasitao Formation consists of marine volcanic sedimentary system withcal-alkaline series volcanic rocks.Upper Carboniferous Batamayineishan Formation consists of continental volcanic eruption system with alkaline series volcanic rocks.Lower Permian Haerjiawu Formation consists of continental volcanic-sedimentary system with sub-alkaline series volcanic rocks.Zhuomubasitao Formation has the characteristics of without obvious Ti negative anomalies and enrichment of LILE indicate that was the product of crustal thickening during late island arc development.Batamayineishan Formation has the characteristics of depletion of HFSE and enrichment of LILE,suggested that it has the typical characteristics of the subduction zone. However,it was explained as back-arc basin environment due to lack of obvious Ce negative anomaly. HaerjiawuFormation has the geochemical features of enrichment of strong incompatible element and obvious negative anomaly with Nb,Ta and Ti,indicate that was in rift environment.Based on geology and geochemistry of late Paleozoic volcanic rocks,we consider that early Devonian was in arc island environment,late Carboniferous was in back-arc basin environment,and Permian was in extension environment,it has important significant for inverting tectonic evolution of late Paleozoic.

关 键 词：准噶尔东北缘 晚古生代 火山岩 地球化学特征 构造演化 

分 类 号：P588.14[天文地球—岩石学] P548[天文地球—地质学]