西藏达龙钨钼多金属矿床地质特征及找矿前景

达龙钨钼多金属矿床地处西藏拉萨市墨竹工卡县境内，位于著名的冈底斯成矿带东段北侧，目前矿区内已探获金属资源量WO3 8.38万t、Mo 2.98万t、Cu+Pb+Zn 5.03万t。结合矿区最新地质工作成果，对区域地质背景、矿区地质特征、矿床地质特征进行了详细分析，并对矿床成因进行了探讨。研究表明：①矿体主要赋存于上二叠统旁那组浅变质砂岩和板岩中，Ⅱ#、Ⅲ-1#、Ⅲ-2#、Ⅳ-1#矿体为主矿体，呈厚大脉状、透镜状及薄脉状产出，受NE向达龙断裂带控制，围岩蚀变发育，蚀变分带明显，矽卡岩化与矿化关系密切；②达龙矿床成因类型为矽卡岩-热液脉型钨钼多金属矿床，成矿物质来源于岩浆，与燕山晚期碰撞型中酸性岩浆活动关系密切，成矿流体具有从高温、高盐度向低温、低盐度演化分异的特征。在上述分析的基础上，从地层、构造、岩浆岩等方面分析了矿区成矿条件并对找矿标志和找矿前景进行了讨论，认为矿区NE向断裂、地层与岩体接触外带、硅化及地表铁帽等蚀变地段、环形线性构造交叉同时硅化及铁化蚀变异常叠加区域、Cu-Pb-Zn-W-Mo异常及低电阻高极化异常为有利的找矿标志；矿区15#勘探线深边部、Ⅰ#、Ⅱ#矿化体北侧以及Ⅳ-1#矿体以南地段找矿潜力巨大，是矿区有利的找矿靶区。

Geological Characteristics and Prospecting Potential of Dalong Tungsten and Molybdenum Polymetallic Deposit in Tibet

Dalong tungsten and molybdenum polymetallic deposit is located in Mozhugongka County in Tibet， which is distributed in the famous northeastern Gangdese metallogenic belt，and about 8.38 ten thousand ton tungsten trioxide，2.98 ten thousand ton molybdenum，5.03 ten thousand ton copper，lead and zinc resources are obtained in the mining area.Based on the latest prospecting results in the mining area，the regional geological background， geological characteristics of the mining area and deposit geological characteristics are discussed，besides that，the deposit genesis，metallogenic conditions and prospecting indicators are also analyzed in detail.The study results show that:①the mineralization bodies （orebodies） are mainly hosted in the shallow metamorphic rocks of the sandstone and slate in Pangna Formation of Upper Permian Series，Ⅱ#，Ⅲ-1#，Ⅲ-2# and Ⅳ-1# orebody belong to main orebodies，which presents thick veins，lenticular and thin veins ，and are controlled by NE trending Dalong fracture，the wall-rock alterations are well developed with alterative zones，and the mineralization is closely associated with skarnization；②Dalong deposit genesis is a large skarn-hydrothermal vein type tungsten molybdenum polymetallic deposit，metallogenic materials derive from magmatic fluids，and it is closely associated with collision type intermediate-acid magmatic activity，the metallogenic fluids have the evolution trend of that from high temperature，high salinity to low temperature and low salinity.Based on the above analysis results，the metallogenic conditions prospecting potential are analyzed from the aspects of strata，structure and magmatic rock，and the results indicatedthat the favorable prospecting indicators of the mining area are NE trending fault，siliconized and iron cap alteration section，the tectonic intersection area of linear and circular structure，simultaneous silicification and ironation alteration，Cu-Pb-Zn-W-Mo geochemical anomaly，low resistivity and high polarizability geophysical abnormality； the prospecting potential of deep and margin of 15# exploration line，north of Ⅰ#， Ⅱ# ore-bodies and south of IV-1# ore-body are huge， they are worth conducting further prospecting and exploration work in the areas.