长江中下游南京(宁)-芜湖(芜)段深部壳幔电性结构——宽频大地电磁测深研究  

The crust-mantle conductivity structure of Nanjing( Ning)-Wuhu( Wu) in the Middle and Lower Reaches of Yangtze River: Broadband magnetotelluric sounding research

作　　者：张昆[1] 严加永[1] 吕庆田[1] 魏文博[2] 邵陆森 王华峰 杨振威[5] 

机构地区：[1]中国地质科学院矿产资源研究所,国土资源部成矿作用和资源评价重点实验室,北京100037 [2]中国地质大学地球物理与信息技术学院,北京100083 [3]中国地质科学院,北京100037 [4]山东省地球物理地球化学勘查院,济南250013 [5]河南理工大学资源环境学院,焦作454003

出　　处：《岩石学报》2014年第4期966-978,共13页Acta Petrologica Sinica

基　　金：国家"深部探测技术与实验研究"专项课题(SinoProbe-03-02);国家自然科学基金重点项目(40930418);中国地质科学院矿场资源研究所基本科研业务费项目(K1318);科技支撑计划课题(2011BAB04B01)联合资助

摘　　要：为了较全面、客观地认识南京(宁)-芜胡(芜)地区岩石圈深部结构,探讨岩石圈热结构和壳、幔物质状态等重要科学问题,为矿集区成矿作用和成矿规律的研究提供依据,我们完成了6条宽频大地电磁测深剖面。通过分析各剖面电性成像结果,讨论了研究区地壳-上地幔导电性的"拟三维"结构,发现测区普遍存在连续的下地壳-上地幔低阻层,仅在巢湖冲褶体断开。结合区域热流结果,我们认为下地壳-上地幔有较好的导电性,可能存在局部"熔融体"或"含水剪切断裂",其物质状态很可能是热的、软弱的。此外,我们通过物质状态和电性界面推断了上地幔隆起的位置和长江深断裂带的分布范围,认为长江断裂带不但存在,而且由多条北深南浅的断裂组成,较为复杂。In order to understand the deep structure of lithosphere more comprehensively and objectively in Nanjing （Ning） -Wuhu （Wu） and explore lithospheric thermal structure and crust, mantle status and other important scientific issues, and provide the basis for ore district mineralization and metallogenic regularity, we finish 6 MT profiles and discuss the ＂ apparent three-dimensional＂ conductivity structure of crust-upper mantle through imaging studies. Find that a big low-resistivity layer exists in crust-upper mantle, and the layer is substantially continuous, but discormects in Chaohu fold belt region. Combined with regional heat flow results, we believe that the lower crust-upper mantle is conductive, and ＂melt＂ or ＂aqueous shear fracture＂ may be existed, and the state of matter is likely to be hot and weak. In addition, we infer the location of upper mantle uplift and distribution range of the Yangtze River deep fault through the material and electrical properties, and we consider that the Yangtze River fault is not only exist, but also composes by a number of faults, and the faults is more complex and deep in the north.

关 键 词：宁-芜火山岩盆地 宽频大地电磁测深 岩石圈 导电性 

分 类 号：P541[天文地球—构造地质学] P631[天文地球—地质学]