喀喇昆仑麦拉山地区水系沉积物地球化学特征与找矿预测  

Geochemical Characteristics of River Sediment and Ore Prediction in the Malashan Area of the Karakoram Region

作　　者：梁东 华北 赵德怀 吴浩 万生楠 谭朝欣 赵晓健[3] 杨志鹏 LIANG Dong;HUA Bei;ZHAO Dehuai;WU Hao;WAN Shengnan;TAN Chaoxin;ZHAO Xiaojian;YANG Zhipeng(Xinjiang Geological Exploration Institute of China Metallurgical Bureau,Urumqi,Xinjiang 830000,China;Institute of Mineral Resources,China Metallurgical Geology Bureau,Beijing 100131,China;Xi’an Center of China Geological Survey,Xi’an,Shaanxi 710054,China)

机构地区：[1]中国冶金地质总局新疆地质勘查院,新疆乌鲁木齐830000 [2]中国冶金地质总局矿产资源研究院,北京100131 [3]中国地质调查局西安地质调查中心,陕西西安710054

出　　处：《现代地质》2023年第3期708-721,共14页Geoscience

基　　金：中国地质调查局地质调查项目(1212011220651、DD20190143);陕西省自然科学基础研究计划项目(2020JQ-440)

摘　　要：喀喇昆仑麦拉山地区成矿条件优越,然而基础地质研究程度不足制约了该区地质找矿取得新突破。本次研究从喀喇昆仑麦拉山地区水系沉积物地球化学特征入手,并与区内元素背景分布特征进行对比分析元素离散分布表明Mo、Pb、Sb、As、Cu、Zn具有富集程度高、分布极不均匀的特征。元素在各地质体分布特征表明神仙湾组上段、龙山组、铁龙滩组地层中铅锌等元素富集,有利于铅锌等矿产的形成。元素共生组合规律表明:Bi、Zn、Pb、Sb、As元素组合指示热液硫化物活动,Cu、Mo、Ag元素组合指示铜多金属矿化异常,Au(W、Mg)元素组合指示金矿化异常,共圈定地球化学综合异常29处。结合区域地质矿产信息和异常查证成果,划分了2个Ⅰ级成矿远景区、4个Ⅱ级成矿远景区和1个Ⅲ级成矿远景区,圈出3个A类找矿靶区,6个B类找矿靶区,4个C类找矿靶区。新发现铅锌矿点4处、铜多金属矿点4处。以Cu、Pb、Zn、Ag为主成矿元素的综合异常与中侏罗统龙山组和上白垩统铁龙滩组对应较好,是寻找层控热液型铜铅锌矿床的有利层位;以Pb、Zn为主成矿元素的综合异常与中—下二叠统神仙湾组对应较好,是寻找低温热液型铅锌矿床的有利地段。Metallogenic conditions in the Melashan area of Karakoram are superior.However,the lack of basic geological research has restricted prospecting breakthroughs in this area.This study starts with stream sediment geochemical survey,and compares with the local background distribution characteristics of elements.The discrete elemental distributions show that Mo,Pb,Sb,As,Cu and Zn are highly enriched and unevenly distributed.The element distribution characteristics in various geological units indicate that elements such as lead and zinc are enriched in the upper section of Shenxianwan Formation,Longshan Formation and Tielongtan Formation,which is conducive to Pb-Zn mineralization.The element association regularity shows that the Bi,Zn,Pb,Sb and As assemblage indicates hydrothermal sulfide activity,the Cu,Mo and Ag assemblage indicates copper polymetallic mineralization anomaly,and the Au(W,Mg)assemblage indicates gold mineralization anomaly,and consequently 29 geochemical anomalies are delineated.Based on the regional geological characteristics and anomaly verification results,two level-I mineral prospect areas,four level-II mineral prospect areas,and one level-III mineral prospect area are divided.Besides,and three A-level prospecting targets,six B-level prospecting targets,and four C-level prospecting targets are delineated.Four lead-zinc deposits and four copper-polymetallic deposits were newly discovered.The comprehensive anomalies of Cu,Pb,Zn and Ag ore-metals correspond well with the Middle Jurassic Longshan Formation and the Upper Cretaceous Tielongtan Formation,which are favorable host for stratabound hydrothermal copper-lead-zinc deposits.The comprehensive Pb-Zn anomaly correspond well with the Middle-Lower Permian Shenxianwan Formation,which is a favorable host for low-temperature hydrothermal lead-zinc deposits.

关 键 词：水系沉积物测量 地球化学特征 找矿预测 喀喇昆仑 

分 类 号：P595[天文地球—地球化学] P612[天文地球—地质学] P632