长江中下游及其邻区深部地球物理背景与含金夕卡岩矿床的分布

长江中下游地区是我国重要的铁铜矿产基地。近十年来,我国所发现的含金夕卡岩矿床和铜伴生金夕卡岩矿床也主要产在长江中下游地区。作者借助12条大地电磁测深剖面、5条地震剖面、层析成像速度结构资料、重磁场等区域的和深部的地球物理资料进行综合对比研究,给出长江中下游及其邻区的三维深部构造格架及其与含金夕卡岩矿床和铜伴生金夕卡岩矿床的分布关系。作者认为,上地幔隆起带(岩石圈地幔减薄带)、上地幔异常区(相对低速区)、壳内高导层隆起带、深断裂(岩石圈剪切带)、地壳上地幔不均匀性块体的边缘、重力高反映的基底隆起区、跳跃磁场反映的岩浆岩带和构造交汇处等诸多因素的共同作用控制着含金夕卡岩矿床和铜伴生金夕卡岩矿床的分布。

DEEP GEOPHYSICAL BACKGROUND AND DISTRIBUTION OF AURIFEROUS SKARN DEPOSITS IN THE MIDDLE AND LOWER YANGTZE VALLEY AND NEIGHBORING AREAS

The middle and lower rearches of the Yangtze River serve as an important iron copper base area of China.The auriferous skarn deposits and copper (associated with gold) skarn deposits discovered in the past ten years are also mainly distributed in the middle and lower reached of the Yangtze River.Based on an integrated correlation and study of regional and deep geophysical data such as 12 magnetotelluric sounding profiles,5 seismic profiles,tomographic imaging velocity structural data and gravity and magnetic field,the authors have formulated the 3D deep tectonic framework of the middle and lower Yangtze valley and its neighborring areas in relation to the distribution of auriferous skarn deposits and copper (associated with gold) skarn deposits.The authors hold that the joint actions of numerous factors such as the upper mantle uplifted zone (the mantle thinned zone of lithosphere),the upper mantle anomalous area (relatively low velocity area),the uplifted zone of intracrustal high conductivity layer,the deep fault (shear zone of lithosphere),the margin of the crust upper mantle uneven masses,the basement uplifted area reflected by gravity high,the magmatic belt and tectonic intersection reflected by skipped magnetic field,control the distribution of auriferous skarn deposits and copper (associated with gold) skarn deposits.