张旗, 王焰, 刘伟, 王元龙. 埃达克岩的特征及其意义[J]. 地质通报, 2002, 21(7): 431-435.
    引用本文: 张旗, 王焰, 刘伟, 王元龙. 埃达克岩的特征及其意义[J]. 地质通报, 2002, 21(7): 431-435.
    ZHANG Qi, WANG Yan, LIU Wei, WANG Yuanlong. Adakite: Its characteristics and implications[J]. Geological Bulletin of China, 2002, 21(7): 431-435.
    Citation: ZHANG Qi, WANG Yan, LIU Wei, WANG Yuanlong. Adakite: Its characteristics and implications[J]. Geological Bulletin of China, 2002, 21(7): 431-435.

    埃达克岩的特征及其意义

    Adakite: Its characteristics and implications

    • 摘要: 讨论了中国东部C型埃达克岩与环太平洋典型埃达克岩的异同点及其不同的产出背景,认为中国东部中生代具埃达克岩特征的中酸性火成岩是陆内岩浆作用的产物,推测是来自岩石圈地幔的玄武质岩浆底侵到加厚的具克拉通性质的陆壳(>50km)底部导致古老的下地壳基性岩部分熔融形成的。论述了埃达克岩,尤其是C型埃达克岩的地球动力学意义,指出埃达克岩的发现开创了岛弧岩浆成因的新系列,是岩石学领域内一个重要的突破,开拓了花岗岩研究的新思路。探讨了埃达克岩可能的形成构造背景,指出利用埃达克岩可以追踪地质历史上的地壳增厚及其相关事件,反演下地壳组成。讨论了埃达克岩与成矿作用的关系。

       

      Abstract: The similarity and difference between C -type adakitic rocks in eastern China and typical Adakite in the Pacific Ocean in respect to geochemistry and tectonic setting are discussed.Mesozoic inter-mediate-acid igneous rocks with adakitic signatures in eastern China are considered as the product of in-tracontinental magmatism.It is inferred that they originated by partial melting of basic rocks in the lower crust due to underplating of basaltic magma from the lithospheric mantle to the bottom of the thickened continental crust(>50km)with cratonic affinity.The geodynamic implications of Adakite,especially C-type Adakite,are dealt with in the paper.Adakite can be considered as a new series of island-arc magma-tism and its discovery marks a major breakthrough in the petrological study and initiates a new way for the study of granitoids rocks.Several possible tectonic settings for the formation of Adakite are also dis-cussed.Adakite is a key to the study of crustal thickening and relevant events in geological history and the backward deduction of the composition of the lower crust.In addition,the relation of Adakite to mineral-ization is also discussed.

       

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