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    路凤香, 王春阳, 胡宝群, 吴其反, 郑建平. 南秦岭下地壳组成及岩石圈的拆离俯冲作用[J]. 中国地质, 2003, 30(2): 113-119.
    引用本文: 路凤香, 王春阳, 胡宝群, 吴其反, 郑建平. 南秦岭下地壳组成及岩石圈的拆离俯冲作用[J]. 中国地质, 2003, 30(2): 113-119.
    LU Feng-xiang, WANG Chun-yang, HU Bao-qun, WU Qi-fan, ZHENG Jian-ping. Structure of the lower crust and detachment and subduction of the lithosphere of the South Qinling[J]. GEOLOGY IN CHINA, 2003, 30(2): 113-119.
    Citation: LU Feng-xiang, WANG Chun-yang, HU Bao-qun, WU Qi-fan, ZHENG Jian-ping. Structure of the lower crust and detachment and subduction of the lithosphere of the South Qinling[J]. GEOLOGY IN CHINA, 2003, 30(2): 113-119.

    南秦岭下地壳组成及岩石圈的拆离俯冲作用

    Structure of the lower crust and detachment and subduction of the lithosphere of the South Qinling

    • 摘要: 提要:根据新提供的Pb同位素组成及岩石地球化学研究成果,本文进一步证实了位于北秦岭北界的明港地区发育的早中生代安山玄武质火山角砾岩岩筒所携带的下地壳捕虏体属于南秦岭。所恢复的南秦岭下地壳剖面自下而上为:底侵成因的变辉长岩—基性麻粒岩(其中含有榴辉岩及辉石岩的透镜体)— 酸性麻粒岩。秦岭造山带总体的岩石圈模型为:南秦岭(扬子块体)向北拆离俯冲,北秦岭地壳向华北仰冲,华北岩石圈呈楔状插入秦岭造山带,拆离面约在中、下地壳之间。南秦岭俯冲岩片延伸的范围在平面上有可能达到400km。

       

      Abstract: Abstract:According to the lead isotopic composition and geochemical study of rocks, this paper further verifies that the xenoliths of the lower crust carried by an Early Mesozoic andesite-basaltic breccia pipe developed in the Minggang area on the northern boundary of the North Qinling belong to the South Qinling. From below upward the reconstructed section of the lower crust below the South Qinling consists of underplating gabbro, basic granulite (which contains lenses of granulite and gabbro) and acid granulite. The general lithosphere model of the Qinling orogenic belt is as follows: the South Qinling crust (Yangtze block) is detached and subducted northward, the North Qinling crust is obducted toward North China, and the lithosphere beneath North China is injected as a wedge into the Qinling orogenic belt, with the detachment surface lying between the middle and lower crusts. In a plan view, the subducting slab of the South Qinling possibly extends 400 km until it reaches here.

       

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