西藏荣那斑岩铜矿地质地球物理特征及找矿意义  

Geological,geophysics features and its exploration significance of Rongna cu deposit in Ngari county of Tibet,China

作　　者：江少卿[1,2] 李彦波 冯军 李力 袁华山 王策[1,2] 费凡 潘燕兵 李丽[1,2] 

机构地区：[1]中铝矿产资源有限公司,北京100082 [2]中国铝业公司,北京100082 [3]西藏地勘局地质五队,格尔木816000 [4]中铝西藏矿业有限公司,拉萨814000

出　　处：《地球物理学进展》2017年第1期167-176,共10页Progress in Geophysics

基　　金：中国铝业公司科技发展基金重点项目(2011KJZD09)资助

摘　　要：荣那铜矿床位于西藏班怒西段多龙斑岩铜矿集区,以往1∶50000磁法和水系沉积物测量已经显示出荣那异常带具有寻找隐伏斑岩铜矿的潜力.为进一步查明该异常区的异常源属性和铜矿地质特征,对以往地质、物探等资料进行了综合研究,并投入了大比例尺磁法和电法测量等物探工作;在优选区内成矿有利部位的基础上,利用钻探施工进行异常查证.区内物探工作将荣那异常带进一步分解为两个次级异常区:在荣那异常区中心呈现低磁、低阻、高极化异常有利成矿区块,在荣那外围异常区呈现环状高磁、高阻、低极化异常环带.进一步在荣那异常区布设两条激电测深剖面,约150 m以深呈现钟状陡峭的低阻高极化异常.通过对该异常进行综合分析,在荣那异常区选定成矿有利部位施工ZK3204钻孔,86.83~1067.6 m进尺处揭露厚大铜矿体,连续穿矿厚度980.77 m,铜平均品位0.69%.矿体呈巨厚橄榄球状,矿石类型为黄铜矿、辉铜矿化、斑铜矿、黄铁矿化浸染状铜矿石.截止2015年末,探获332+333+334级别铜金属量1097.92万吨,平均品位0.53%.荣那铜矿勘查工作表明,该物探异常是由隐伏铜矿体引起,铜矿类型属斑岩型.阿里地区的铜矿勘查工作表明,青藏高原等高海拔地区高精度磁法和激电测量是经济有效快速圈定靶区的铜矿勘查手段.Rongna copper deposit is located in Duolong porphyry copper ore-forming region, western of Bangongco-Nujiang suture zone,Tibet. Previous 1 ∶50000 magnetic survey and water stream sediment survey have shown Rongna anomaly,and indicated its potential to find covered porphyry copper deposit. In order to verify the abnormal source properties and geological characteristics of Rongna anomaly, geological and geophysical data have been comprehensively researched,meanwhile both large-scale magnetic and induced-polarization（ IP） geophysical survey are conducted.After delimited mineralize potential zone, dillholes have been operated to test the anomaly zone. Rongna geophysical anomaly can be further subdivided into two sub-anomalous areas： the center anomaly zone shows low magnetic,low resistance,high polarization,and favorable mineralization characters; the peripheral zone presents high magnetic, high resistance, and low polarization. Two IP sounding inversion profiles have been laid out in the center of Rongna anomaly, showing a steep low resistance and high polarization anomaly in bell shape. Through a comprehensive analysis of the anomalies,drillhole ZK3204 is operated in the center of Rongna anomaly, thick cooper orebody is unveiled between interval of 86. 83 ~ 1067. 6 m,with continuous bonanza thickness of980. 77 m,and 0. 69% copper grade on average. The orebody shows thick ellipsoidal shape. The ore type is disseminated copper ore,containing major minerals of chalcopyrite,chalcocite,bornite,and pyrite. The copper resource in 332 ＋ 333 ＋ 334 categories is10,979,200 tons,with an average grade of 0. 53%. The deposit type is porphyry. The exploration work in Ngari county indicates that both large scale magnetic method and induced polarization method are rapid cost-effective approaches to delineation of copper target in Tibet plateau.

关 键 词：阿里 荣那 铜矿 磁异常 激电异常 地质特征 找矿意义 

分 类 号：P631[天文地球—地质矿产勘探]