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中国东部深部构造特征及其与矿集区关系
Deep-seated structure characteristics of eastern China and its relation with metal mineralization-concentrated region
【摘要】 文中以地震层析原始数据为基础,结合大地电磁测深和热流值数据,对老资料重新开发,编制了中国东部岩石圈厚度图、大地热流值图、岩石圈构造与矿集区关系图等,在此基础上对中国东部上地幔岩石圈-软流圈构造及其变异进行了初步研究,认为:(1)中生代燕山期较大型深部构造(如软流圈上涌体)的地震层析影象可存留至今,运用大地热流值及其相应浅表岩浆岩、矿集区等特征差异可以将中、新生代深部构造加以区分;(2)中国东部深部构造总特征:上地幔岩石圈-软流圈构造起伏变化,岩石圈西厚东薄,软流圈上涌发育且形式各异。大体可分为华南(构造线呈NWW)、华北(构造线近SN)、东北(构造线呈NNE)三大块,其基本特征各异。整个中国东部深部构造中,软流圈上涌起主导作用;(3)中生代软流圈上涌是相应浅表燕山期花岗质岩形成的根源,并与金属矿集区密切相关,新生代软流圈上涌则是大陆裂谷、玄武岩喷发及大型油气田形成的基础;(4)岩石圈减薄的主因是软流圈上涌,中生代燕山期主要减薄于中国东部大陆内部,新生代主要减薄于偏东部沿海区域。
【Abstract】 Based on published seismic tomography and magnetotelluric data, combined with heat flow values, the authors constructed maps of lithosphere thickness, heat flow values, and of the relationship between lithosphere structure and metallogenic districts in eastern China. On this basis, the authors focused on the upper mantle lithosphere-asthenosphere structure of eastern China, and concluded the following: (1)seismic tomography images can diotinguish between Mesozoic and Cenozoic deep-seated structures,using differences in heat flow values, magmatic rocks and metallogenic districts;(2) the principal features of deep-seated structure of eastern China may be summarized as follows: a) the upper mantle lithosphere-asthenosphere shows an undulating structure, with the lithosphere being thicker in the west and thinner in the east, and b) the mantle asthenosphere upwelling, can be divided into three blocks:①south China block (structure line shows NWW), ②north China block (structure line shows nearly N-S), and ③ a northeast block (structure line shows ENE) with their respective different features, and for the deep-seated structure of eastern China, asthenosphere upwelling plays an dominant role; (3) Mesozoic asthenosphere upwelling is responsible for the formation and emplacement of Yanshanian granitic rocks and associated mineralization,and the Cenozoic asthenosphere upwelling is responsible for continental rifting, basaltic volcanism and larger oil-gas field; (4) lithosphere thinning is also related to asthenospheric upwelling, eastern China continental mass was thinned mainly in the Mesozoic (Yanshanian event) and the east coast in the Cenozoic.
【Key words】 deep-seated structure; lithosphere-asthenosphere structure; metalogeny; asthenosphere upwelling; lithosphere thinning;
- 【文献出处】 地学前缘 ,Earth Science Frontiers , 编辑部邮箱 ,2007年03期
- 【分类号】P542
- 【被引频次】46
- 【下载频次】654