东昆仑喀雅克登塔格杂岩体的SHRI MP年龄及其地质意义  

SHRIMP ages of Kayakedengtage complex in the East Kunlun Mountains and their geological implications

作　　者：谌宏伟[1] 罗照华[2] 莫宣学[2] 张雪亭[2] 王瑾[3] 王秉璋[3] 

机构地区：[1]中国地质大学北京市水资源与环境工程重点实验室,北京100083 [2]中国地质大学地球科学与资源学院 [3]青海省地质调查院,青海西宁810001

出　　处：《岩石矿物学杂志》2006年第1期25-32,共8页Acta Petrologica et Mineralogica

基　　金：中国地质调查局地质调查项目(200113900069_4_3;200113900018_5)

摘　　要：喀雅克登塔格杂岩体位于东昆仑祁漫塔格山东南部,由辉长岩、闪长岩、石英闪长岩、花岗闪长岩、二长花岗岩、正长花岗岩等岩石类型组成,具有典型的岩浆混合特征。通过对杂岩体中辉长岩和二长花岗岩的锆石进行SHRIMP测年,分别获得403.3±7.2Ma和394±13Ma两个极为接近的岩浆锆石年龄以及1116Ma的继承锆石年龄。锆石形态学特征显示辉长岩和二长花岗岩中锆石的大致结晶温度分别为850～900℃和600～850℃,提供了杂岩体形成的深度信息。测年结果为研究东昆仑造山带的演化历史提供了重要的年代学资料。Kayakedengtage complex, located in southeastern Qimantage Mountain of the East Kunlun Mountains, consists of gabbro, diorite, quartz diorite, granodiorite, adamellite and syenogranite which are products of a typical magmatic mixing process. The SHRIMP dating of gabbro and adamellite samples yielded magmatic ages of 403.3 ＋ 7.2 Ma and 394 ＋ 13 Ma and inherited zircon age of 1 116 Ma. The morphological features of zircons from gabbro and adamellite indicate that the zircon crystallization temperatures of these two rocks are 850 --900℃ and 600--850℃, respectively, which implies the formation depth of the complex. The dating results provide important data for the evolutionary history of the East Kunlun orogenic belt.

关 键 词：锆石SHRIMP年龄 岩浆混合 锆石形态 早泥盆世 喀雅克登塔格 东昆仑 

分 类 号：P588.12[天文地球—岩石学] P597.3[天文地球—地质学]