新疆若羌县砂梁西逆冲推覆构造特征及勘查找矿意义  

Characteristics and Prospecting Significance of the Thrust Nappe Structure in Shaliangxi,Ruoqiang County,Xinjiang,China

作　　者：闵壮 陈正乐[1,2,3] 王永 王威[3] 霍海龙 潘家永 朱炳玉[3] 杜晓飞 韩凤彬 张文高[2] 吴玉 MIN Zhuang;CHEN Zhengle;WANG Yong;WANG Wei;HUO Hailong;PAN Jiayong;ZHU Bingyu;DU Xiaofei;HAN Fengbin;ZHANG Wengao;WU Yu(State Key Laboratory of Nuclear Resources and Environment,East China University of Technology,Nanchang 330013,Jiangxi,China;Institute of Geomechanics,Chinese Academy of Geological Sciences,Beijing 100081,China;The National 305 Project Office of the People’s Government of Xinjiang Uygur Autonomous Region of China,Urumqi 830000,Xinjiang,China;Beijing Research Institute of Uranium Geology,CNNC,Beijing 100029,China)

机构地区：[1]东华理工大学,核资源与环境国家重点实验室,江西南昌330013 [2]中国地质科学院地质力学研究所,北京100081 [3]新疆维吾尔自治区人民政府305项目办公室,新疆乌鲁木齐830000 [4]核工业北京地质研究院,北京100029

出　　处：《大地构造与成矿学》2024年第5期939-947,共9页Geotectonica et Metallogenia

基　　金：国家自然科学基金项目(42172258);“西昆仑-阿尔金锂等稀有金属找矿预测与勘查示范”项目(2021YFC2901904);中国铀业有限公司-东华理工大学核资源与环境国家重点实验室联合创新基金项目(NRE2021-01);中国地质调查局地质调查项目(DD20221660-3);中核集团集中研发项目(地SD01-03-01);江西省研究生创新专项基金项目(YC2022-B178)联合资助。

摘　　要：青藏高原北缘阿尔金成矿带新发现了多处古生代的伟晶岩型锂铍矿床,其中以吐格曼、阿亚格、瓦石峡南锂铍矿床为代表,显示该成矿带具有良好的稀有金属找矿前景。近年来,在若羌县砂梁西铁矿区中也发现了伟晶岩型锂-铌钽矿化,含矿伟晶岩赋存于长城系巴什库尔干岩群和古生代花岗质岩体中,钻探显示其北带部分伟晶岩型矿体深部具有“无根”的特征。本文基于野外地质调查资料,在矿区发现一条第四纪低角度逆冲推覆构造,严格控制着含矿伟晶岩的深部空间展布特征。针对逆冲推覆断层中发育的擦痕,利用Faultkin软件进行了古应力方向的反演分析,确定逆冲推覆的最大主应力作用方向为NNW-SSE。综合分析区域资料,认为阿尔金造山带北缘第四纪逆冲推覆构造形成于青藏高原自南向北扩展期间,伴随着阿尔金走滑断裂的左旋走滑作用,在阿尔金北缘断裂附近出现了大规模的逆冲推覆。逆冲推覆构造的发现及其推覆方向的准确判定,下一步对该区分析含矿伟晶岩矿体的空间展布特征及其找矿工程部署提供了参考资料。Several Paleozoic pegmatitic lithium-beryllium deposits have been discovered in the Altyn metallogenic belt located on the northern margin of the Qinghai-Tibet Plateau,including the Tugeman,Ayage,and Washixianan Lithium-beryllium deposits,indicating that this metallogenic belt has good prospect for rare metal prospecting.In recent years,pegmatite-type Li-Nb-Ta mineralization has also been found in the Shaliangxi iron producing area,Ruoqiang County.The ore-bearing pegmatites occur in the Proterozoic Kuergan Group and Paleozoic granitoids.However,drilling has shown that some pegmatite-type ore bodies in the northern zone are“root-less”.Based on field geology,a Quaternary low-angle thrust nappe structure was found in the mining area,which strictly controlled the deep spatial distribution of the ore-bearing pegmatite.According to the striations in the fault plane,an inversion analysis of the paleostress direction was carried out using the Faultkin software,and the maximum principal stress direction of the thrust nappe was determined to be NNW-SSE.Based on a comprehensive analysis of the regional data,it is believed that the Quaternary thrust nappe structure in the northern margin of the Altyn orogenic belt was formed during the SN extension of the Qinghai-Tibet Plateau.With the sinistral strike-slip of the Altyn strike-slip fault,the large-scale thrust nappe occurred near the northern edge of the Altyn.The discovery of the thrust nappe structure and accurate determination of the nappe direction provide reference for further analyzing of the spatial distribution of ore-bearing pegmatite ore bodies and the deployment of prospecting projects in this area.

关 键 词：逆冲推覆构造 构造应力场 第四纪 阿尔金造山带 

分 类 号：P613[天文地球—矿床学] P542[天文地球—地质学]