西天山察汉乌苏铁矿锆石U-Pb年代学及Lu-Hf同位素示踪  

Zircon U-Pb Dating and Lu-Hf Isotopic Tracing in the Chahanwusu Iron Mine,Western Tianshan

作　　者：邢金春 白权金 郭新成[2] 张建收[2] 高军 杨有生[2] Xing Jinchun;Bai Quanjin;Guo Xincheng;Zhang Jianshou;Gao Jun;Yang Yousheng(Mineral Resources Reserve Evaluation Center of Xinjiang,Urumqi,Xinjiang,830000,China;The 11th Geological Branch of Xinjiang Bureau of Geology and Mineral Resources,Changji,Xinjiang,831100,China)

机构地区：[1]新疆维吾尔自治区矿产资源储量评审中心,新疆乌鲁木齐830000 [2]新疆维吾尔自治区地质矿产勘查开发局第十一地质大队,新疆昌吉市83100

出　　处：《新疆地质》2021年第3期395-403,共9页Xinjiang Geology

基　　金：西天山阿吾拉勒铁矿带矿集区深部资源预查与技术示范(2018YFC0604004)项目资助。

摘　　要：察汉乌苏铁矿位于西天山阿吾拉勒晚古生代裂谷带东段,矿体赋存于下石炭统大哈拉军山组第三段火山岩中。通过对察汉乌苏铁矿矿体顶板围岩进行岩石学、岩石地球化学、同位素年代学分析来探讨火山岩形成的构造环境、成岩时代及成岩物质来源。地球化学分析表明,察汉乌苏铁矿矿体顶板围岩为钙碱性系列,构造环境为岛弧。通过锆石U-Pb测年,获得^(206)Pb/^(238)U加权平均年龄为(324.3±3.4)Ma,属早石炭世晚期。二阶段模式年龄tMD2变化于618.40~903.84 Ma,具古老地壳的源区属性,察汉乌苏铁矿成岩物质来源于亏损地幔并有基底物质的加入。Chahanwusu iron mine is situated at the east of the late Paleozoic rift zone in the Awulale,Western Tianshan.The ore bodies occur in the volcanic rocks of the third member from the lower Carboniferous Dahalajunshan formation.Structure setting,diagenesis phase and mineral source of volcanic rocks in Chahanwusu iron mine were discussed in this paper through performing petrology,petrochemistry and isotopic geochronology on roof rocks.Geochemical analysis shows that the roof rocks are dominated by calc alkaline series developing in island arc.Weighted average age of ^(206)Pb/^(238)U derived from zircon U-Pb dating is 324.3±3.4 Ma,indicating that minerals were formed at late Early Carboniferous.Two-phase age(tMD2)varies from 618.40 Ma to 903.84 Ma,suggesting that minerals were mainly sourced from ancient crust.The lithogenous material of the Chahanwusu iron mine was derived from depleted mantle mixed with material from basement.

关 键 词：中亚造山带 阿吾拉勒晚古生代裂谷带 大哈拉军山组 地球化学特征 构造背景 LA-ICP-MS锆石U-Pb LU-HF同位素 

分 类 号：TF521[冶金工程—钢铁冶金] P597[天文地球—地球化学]