西藏甲玛矿区三维地质建模与层状矽卡岩靶区预测  

3D geological modeling and stratified skarn target prediction in the Jiama deposit,Tibet

作　　者：王素芬 屈挺 贺日政[1] 丁毅[3] 刘建利 陈小龙 李冰 卢晓 WANG Sufen;QU Ting;HE Rizheng;DING Yi;LIU Jianli;CHEN Xiaolong;LI Bing;LU Xiao(Sinoprobe Center,Chinese Academy of Geological Sciences,Beijing 100037,China;Shaanxi Geology and Mining Geophysical and Geochemical Exploration Team Co.Ltd.,Xi’an 710043,Shaanxi,China;Institute of Geology,Chinese Academy of Geological Sciences,Beijing 100037,China)

机构地区：[1]中国地质科学院地球深部探测中心,北京100037 [2]陕西地矿物化探队有限公司,陕西西安710043 [3]中国地质科学院地质研究所,北京100037

出　　处：《地质通报》2021年第12期2110-2122,共13页Geological Bulletin of China

基　　金：国家重点研发计划课题《典型矿集区深部地球物理探测技术示范》(编号:2018YFC0604102);中国地质调查局项目《冈底斯构造带关键地区深部地质调查》(编号:DD20190015)。

摘　　要：西藏甲玛矿区是冈底斯成矿带非常典型的多金属矿床,理论预测研究认为,在矿集区深部发育隐伏的斑岩-矽卡岩矿体,而基于矿区钻孔覆盖的勘查模型对外围区潜在靶区预测程度较低。以甲玛矿区45口钻孔岩心的密度、磁性、电阻率、极化率等物性资料为基础,分析了覆盖甲玛矿集区及外围的大地电磁测深三维数据体,基于GOCAD软件平台,通过离散光滑插值法与随机模拟算法,构建了甲玛矿区的地层岩性-地球物理三维可视一体化模型;结合大地电磁测深11条剖面的二维地质解译成果,精细刻划了3000 m以浅的三维矽卡岩体发育特征,并通过使用未参与建模的甲玛科学深钻JMKZ-1进行验证,结果显示三维地质模型具有较好的一致性;基于构建的矽卡岩成矿模型,结合甲玛矿区及邻区岩(矿)石电性参数特征分析和三维矽卡岩的电性结构,预测了甲玛矿区的层状矽卡岩靶区,为深部资源潜力评价及矿集区增储目标提供三维建模技术示范。The Jiama deposit in Tibet is a very typical polymetallic deposit in the Gangdise metallogenic belt.Through theoretical prediction and research,it is believed that concealed porphyry-skarn ore bodies are developed in the deep part of the ore-concentrated area.However,the exploration model based on the borehole coverage of the mining area has a low degree of prediction of the potential target in the peripheral area.Based on the density,magnetic properties,resistivity,and polarizability data of 45 borehole cores in the Jiama deposit,the three-dimensional magnetotelluric sounding data covering the Jiama deposit and its periphery were analyzed.Based on GOCAD software,the stratum lithology-geophysical three-dimensional visualization integrated model of the Jiama deposit was constructed through discrete smooth interpolation and stochastic simulation algorithms.Combined with the results of 2 D geological interpretation of 11 magnetotelluric(MT)profiles,the development characteristics of 3 D skarn bodies below 3000 m were finely depicted and verified with the Jiama Scientific Deep Drill JMKZ-1 which was not involved in the modeling.The results show a consistency agreement.Besides,based on the skarn metallogenic model,combined with the analysis of the electrical parameters of the Jiama deposit and adjacent areas,as well as the electrical characteristics of the three-dimensional skarn,the favorable target area of stratified skarn in Jiama deposit is predicted.The results can provide a demonstration of 3 D modeling technology for the evaluation of deep resource potential and reserves increasing in the mining area.

关 键 词：甲玛矿区 GOCAD软件 三维地质建模 层状矽卡岩 靶区预测 

分 类 号：P62[天文地球—地质矿产勘探]