东昆仑黑海地区加里东期过铝质花岗岩岩石学、地球化学特征及地质意义

发布时间：2018-07-03 04:57

本文选题：东昆仑造山带 + 黑海　；参考：《地球科学(中国地质大学学报)》2016年01期

【摘要】：东昆仑黑海地区发育加里东期过铝质花岗岩(424.0~420.5Ma),其形成与地壳的发展演化密切相关,主要通过岩相学和地球化学方法对其进行了研究.黑海过铝质花岗岩由黑云母英云闪长岩、黑云母花岗闪长岩、黑云母花岗岩、二云母花岗岩和白云母花岗岩组成.SiO_2变化区间为65.32%~75.87%,K_2O/Na_2O为0.47~1.52,δ为1.09~3.00,为钙碱性-高钾钙碱性系列;A/CNK为1.02~1.31,属于过铝质-强过铝质花岗岩.稀土元素具有轻稀土相对富集和重稀土相对亏损的特征,中等负铕异常.微量元素具有相对选择性富集大离子亲石元素而相对亏损高场强元素的特征.源区参与熔融物质由以变杂砂岩为主,向以变泥质岩为主过渡.结合区域资料,认为黑海过铝质花岗岩是东昆南俯冲增生杂岩楔发生伸展减薄引起地幔物质底侵而促使富硅铝地壳物质发生不同程度部分熔融形成.
[Abstract]:Caledonian peraluminous granites (424.0 ~ 420.5 Ma) were developed in the Black Sea area of East Kunlun, and their formation is closely related to the development and evolution of the crust, which has been studied mainly by means of lithofacies and geochemistry. The Black Sea peraluminous granite consists of biotite quartz diorite, biotite granite, The variation range of the composition of dimite granite and Muscovite granite. SiO2 is 65.32 and 75.87. the K _ 2O / Na _ 2O / Na2O is 0.47 ~ 1.52, 未 is 1.09 ~ 3.00, and the calc-alkaline-high-potassium calc-alkaline series A / R _ (CNK) is 1.02n 1.31, which belongs to peraluminite-strong peraluminous granite. Rare earth elements are characterized by relative enrichment of light rare earth elements and relative depletion of heavy rare earths, and moderate negative europium anomalies. Trace elements are characterized by relatively selective enrichment of large ion lithophile elements and relative depletion of high field strength elements. The source region participated in the transition of melt material from metamorphic sandstone to argillaceous rock. In combination with regional data, it is considered that the Black Sea peraluminous granite is caused by extensional thinning of the subductive complex in the southern part of East Kunn, resulting in the submersion of mantle material, which leads to the formation of partial melting of the silicon-rich aluminum-rich crustal material in varying degrees.
【作者单位】：中国地质大学地球科学学院;陕西省地质调查中心;
【分类号】：P588.121;;P595;;P597.3

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