西昆仑甜水海地区泉水沟北东侧花岗闪长岩体地球化学特征及地质意义  

Petrogeochemistry and Its Geological Significance of Granodiorite Intrusive on the Northeast Side of the Quanshui Valley in the Tianshuihai Region,West Kunlun

作　　者：赵波 陈思尧 李有波 孙勇[1] ZHAO Bo;CHEN Si-yao;LI You-bo;SUN Yong(Regional Geological Surveying Team,BGEEMRSP,Chengdu 610213;Sichuan Institute of Geological Survey,Chengdu 610081)

机构地区：[1]四川省地质矿产勘查开发局区域地质调查队,成都610213 [2]四川省地质调查院,成都610213

出　　处：《四川地质学报》2021年第S01期3-11,共9页Acta Geologica Sichuan

基　　金：新疆维吾尔自治区地质勘查基金项目新疆甜水海地区1∶5万I44E003007等四幅区域地质调查(K15-1-LQ07)资助。

摘　　要：泉水沟北东侧花岗闪长岩体分布于泉水沟-冰水河断裂以北,是西昆仑三十里营房-大红柳滩-泉水沟构造-岩浆岩带的重要组成部分。LA-ICP-MS锆石U-Pb年代学研究结果显示岩体侵位时间为224.31±0.99Ma,形成时代为晚三叠世。地球化学分析显示岩石具有富硅、富碱、富钾,贫锰、钛的特点,铝饱和指数A/CNK=1.03-1.07,总体为过铝质高钾钙碱性S型花岗岩;岩石富集轻稀土元素,具铕负异常、铈轻微负异常;Rb、Th、La、Nd明显富集,Ba、Ta、Sr、Zr明显亏损。岩浆来源于地壳,是由地壳岩石部分熔融形成的。岩石具有同碰撞型花岗岩特征,推测岩体可能是可可西里-松潘前陆盆地闭合期间形成的碰撞型侵入岩。Granodiorite Intrusive on the northeast side of the Quanshui Valley in the Tianshuihai Region,west Kunlun is an important part of the Sanshiliyingfang-Dahongliutan-Quanshuigou valley tectonic-magmatic belt.The zircon U-Pb dating indicates the intrusive was emplaced during the Late Triassic with 224.31±0.99 Ma.Geochemically,the intrusive is characterized by enrichment in Si and K and depletion in Mn and Ti with A/CNK ratios of 1.03-1.07,belonging to peraluminous high-potassium calc-alkaline S-type granite.The rock is rich in Rb,Th,La and Nb and depleted in Ba,Ta,Sr and Zr with negativeδEu andδCe values.The granodioritic magma was derived from partial melting of crustal rock.The rock is characterized by syn-colletion granite which may be emplaced during the closure of the Hoh-Xil-Songpan foreland basin.

关 键 词：甜水海地区 花岗闪长岩 锆石U-PB年龄 岩石地球化学 

分 类 号：P595[天文地球—地球化学]