新疆柯坪库木如吾祖克地区二叠纪火山岩
The Premian volcanic rocks from Kumuruwuzuke area, Keping County
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摘要: 新疆柯坪库木如吾祖克地区二叠纪火山岩产于柯坪微地块中,为陆相火山岩,主要由基性熔岩 (辉石玄武岩 )和酸性凝灰岩组成,具双峰式火山岩系组合特征。火山岩为 3个火山喷发旋回的产物,从下至上基性熔岩主元素成分成规律性变化,表明基性熔岩为同源岩浆分异演化的产物。基性熔岩具有大陆火山岩性质,形成于大陆拉张环境。该二叠纪火山岩为天山造山带石炭—二叠纪大规模裂谷作用在柯坪古老微地块上的反映。Abstract: The Permian volcanic rocks from Kumuruwuzuke area in Keping county occurred in Keping Massif, which erupted in land faces and dominated by pyroxene basalt and acid pyroclastic rocks with the characteristics of bi-modal volcanic rocks series. There exists three eruption cycles and the major elements of the basalts changed regularly from the bottom to the top, indicates the basalts are derived from the evolution of same source magma. The geochemical characteristics of the basalts show they are continental tholeiite and formed in continental extension environment(initial stage of continental rift). In a word,the Permian volcanic rocks from Kumuruwuzuke area are the reflection of Carboniferous-Permian continental riftism in Keping micro-massif.