东昆仑印支期区域构造背景的花岗岩记录  

The Record of Indosinian Tectonic Setting from the Granotoid of Eastern Kunlun Mountains

作　　者：袁万明[1] 莫宣学[2] 喻学惠[2] 罗照华[2] 

机构地区：[1]中国科学院高能物理研究所,北京100080 [2]中国地质大学,北京100083

出　　处：《地质论评》2000年第2期203-211,共9页Geological Review

摘　　要：研究表明:东昆仑未见早三叠世花岗岩出露;中三叠世花岗岩仅见于昆中区;晚三叠世花岗岩在昆北区、昆中区和昆南区广为分布。昆中区花岗岩(I型)形成于昆南板片向北俯冲的碰撞造山阶段;其S型、A型花岗岩的产出,是陆内俯冲作用的结果。昆北区出露的I型、S型、A型花岗岩,形成于昆中板片,在晚三叠世沿昆中断裂发生的陆内俯冲。A型花岗岩的产出表明进入造山后阶段。因此,早、中三叠世昆南板片沿昆南缝合带向北造山俯冲,晚三叠世沿昆南断裂和昆中断裂均发生了陆内俯冲过程。昆南缝合带是两个陆壳的俯冲带。Middle Triassic A-type granitoid and other types of granitoid in the central Kunlun region were formed respectively in post orogeny and collision-orogenic stage of southern Kunlun subplate subducting north. The occurrence of late Triassic muscovite/two-mica granites and S-, I- and A-type granitoids in the central Kunlun region, and I-type granitoid in northern margin of southern Kunlun region are the result of intracontinental subduction, in which the southern Kunlun fault is the underthrust zone. Late Triassic anorogenic A-type granites are a indication that intracontinental subduction of southern Kunlun subplate ended. Meanwhile, the I-, S- and A-type granitoids in the northern Kunlun region were formed by intracontinental subduction of the central Kunlun subplate along the Mid-Kunlun fault in late Triassic epoch. Early Triassic granitoid is not found. Therefore, the early-middle Triassic epoch in the eastern Kunlun area fell into the period of the southern Kunlun subplate underthrusting north along the central Kunlun fault. Both the southern Kunlun fault and the central Kunlun fault went through complete intracontinental subduction in late Triassic epoch.

关 键 词：区域构造背影 俯冲作用 构造-岩浆活动 花岗岩 

分 类 号：P542[天文地球—构造地质学]