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长江中下游成矿带位于大别造山带、长江中下游凹陷、江南隆起带等大地构造单元结合部位,通过在研究区内布设两条首尾相接共计150km长的大地电磁剖面,获得了50km以浅岩石圈尺度的电性分布.长江中下游地区中段地下电性结构显示出在地下10km和30km处分别存在明显的圈层结构,以此认为现今横向稳定的“电莫霍”反映了研究区经历燕山期陆内构造-岩浆活动后已基本上完成壳幔重新平衡;而分隔大地构造单元的郯庐断裂带、长江断裂带以及江南断裂带在电性上具有特征的梯度显现,在印支造山期后的引张背景下,断裂带成为强伸展活动带与控制了燕山期大范围的陆内岩浆活动;高导地幔的局域性存在以及从北向南地幔导电性的变化反映了在经受深部动力学过程中处于不同大地构造部位的地幔所遭受的不同类型的改造以及地幔深部的构造极性.
The middle and lower reaches of the Yangtze River metallogenic belt is located in the Dabie orogenic belt, the Yangtze River sag, Jiangnan uplift and other geotectonic units and other parts of the study area by laying two end to end a total of 150km of the earth’s electromagnetic cross section, obtained 50km shallow The distribution of lithospheric scales in the middle reaches of the Yangtze River shows that the subsurface structures in the middle reaches of the Yangtze River have obvious spheric structures at 10 km and 30 km below the ground surface respectively, After the Yanshanian intracontinental tectono-magmatic activity, the area has basically completed the crust-mantle rebalancing. The Tanlu fault zone, the Changjiang fault zone and the Jiangnan fault zone that separate the tectonic units show a characteristic gradient in electrical properties. In the background of extension after the orogeny, the fault zone became a strong extensional activity zone and controlled a large range of intracontinental magmatism during the Yanshanian period. The local existence of the high-conductivity mantle and the conductivity of the mantle from north to south reflected that at The different types of modifications experienced by mantle beneath deep earth tectonics and the structural polarities of deep mantle are undergone with deep kinetics.