西藏东坡蛇绿岩体深部结构的地球物理特征及其找矿意义  

Geophysical characteristics and prospecting significance of deep structures in Dongpo ophiolite body, Tibet

作　　者：姜枚[1,2] 杨经绥[1] 谭捍东[3] 钱荣毅[3] 张聿文[3] 彭淼[1] 许乐红[1] 张立树[1] 李庆庆[1] 郭帅[1] 宋昊翔 

机构地区：[1]中国地质科学院地质研究所大陆构造与动力学国家重点实验室,北京100037 [2]中国地质科学院矿产资源研究所,北京100037 [3]中国地质大学(北京),地球物理与信息技术学院,北京100083

出　　处：《中国地质》2015年第5期1179-1187,共9页Geology in China

基　　金：大陆科学钻探选址与钻探实验项目(SinoProbo-05-07)资助

摘　　要：在西藏西部雅鲁藏布江南岸的东坡岩体进行了多种方法的地球物理探测,由地面磁测精确定位的航空磁测异常反演了东坡岩体深部磁性体范围;反射地震探测划分出了与地表出露蛇绿岩体反射波特征不同的岩体下部弱反射部位;同时,由大地电磁法确定了岩体下部的低阻体也都处于大致相同的部位。地面出露的蛇绿岩体向下延伸,整体呈锅底状,其中部具有较低电阻和弱反射波特征,同时,在1.5~3.0 km范围的磁性矿物相对较发育,可能正是含铬岩体矿化蚀变作用较强的地段,在罗布莎矿区有类似的特征,这对找矿是有利的部位。Geophysical survey of Dongpo rock mass on the south bank of Yarlung Zangbo River in western Tibet was carried out using multiple methods, and the inversion of aeromagnetic survey anomaly precisely positioned by ground magnetic survey revealed the range of the deep magnetic body in Dongpo rock mass; seismic reflection survey delineated the weak reflection places underthe rock mass with reflected wave characteristics different from those of outcropping ophiolite body; meanwhile,as confirmed by MT method, the low- resistivity bodies under the rock mass are at the roughly identical places. The outcropping ophiolite body extends downward, resembling a pot bottom as a whole, and its middle part is characterized by low resistivity and weak reflected wave. In addition, magnetic minerals are relatively developed at the depths of 1.5km- 3.0 km, which might be the very section of chromium-bearing rock mass having strong mineralization and alteration; the similar characteristics were observed in the Luobusha mining area, and hence these places are favorable for ore prospecting.

关 键 词：东坡蛇绿岩体 反射地震 航磁异常 电阻率异常 找矿模型 

分 类 号：P631[天文地球—地质矿产勘探] P612[天文地球—地质学]