藏东怒江板块结合带郭庆复式花岗岩体特征及其成因

FEATURES AND GENESIS OF KORQN COMPOSITE GRANITE MASS IN NUJIANG PLATE JUNCTION,EAST TIBET

根据作者在“三江”地区进行１∶２０万洛隆幅区域地质调查工作中收集的资料，对产出于怒江板块结合带东侧的郭庆复式花岗岩体进行了解体，将岩体划分为燕山早期的黑云母二长花岗岩，燕山晚期的黑云母石英正长岩、黑云母花岗闪长岩三种岩石类型。通过对它们的地质学、岩石学、岩石地球化学特征的研究表明，这三种侵入岩分属陆壳改造Ｓ型花岗岩和壳幔同熔Ⅰ型中酸性岩。燕山早期花岗岩形成于同碰撞造山期，燕山晚期黑云母石英正长岩形成于板块碰撞后的抬升阶段，燕山晚期黑云母花岗闪长岩形成于造山晚期构造环境，是区内板块构造不同演化阶段的产物。

Korqn composite granite mass in Nujiang plate junction may be divided into early Yanshanian biotite adamellite,late Yanshanian biotite quartz syenite and biotite granodiorite Geological,petrographical and lithogeochemical features indicate that they belong to continental crust transformationtype (S type) granite and crust mantle syntexitype (I type) intermediate and acid rocks,respectively They were formed in different evolutionary stages of plate tectonics The early Yanshanian biotite adamellite was formed in collision synorogenic stage,the late Yanshanian biotite quartz syenite was formed in uplifting stage after collision and the late Yanshanian biotite granodiorite was formed in postorogenic stage