中祁连北缘野牛沟-托勒地区晋宁期花岗岩的地质意义  

Geological significance of granite of Jinningian age in Yeniugou-Tuole region on the northern margin of Centrd Qilian block

作　　者：薛宁[1] 王瑾[1] 谈生祥[1] 林海[1] 李五福[1] 任晋祁[1] 刘生军[1] 

机构地区：[1]青海省地质调查院,青海西宁810012

出　　处：《青海大学学报（自然科学版）》2009年第4期23-28,共6页Journal of Qinghai University(Natural Science)

摘　　要：阐述了在中祁连陆块北缘野牛沟-托勒地区原划分的古元古代托赖(岩)群中识别并划分出了晋宁期片麻状花岗岩。它侵位于中元古代中浅变质岩系湟中群以及新解体出的中-新元古代托勒片岩中,单颗粒锆石铀-铅同位素年龄为(837.8±58)Ma、(842±37)Ma,表明它们是晋宁期岩浆事件的产物,地球化学特征显示形成于碰撞构造环境;该片麻状花岗岩的发现,对于祁连造山带前震旦纪基底的深入研究及更进一步确定该地区存在的晋宁期碰撞造山作用提供了直接证据。The gneissic granite of Jinningian Age is distinguished from Tuole Group complex of Paleoproterozoic Era in Yeniugou - Tuole region on the northern margin of Central Qilian Block, and it intrudes low - medium metamorphic rocks of Huangzhong Group of Mesoproterozoic Era and Tuole schist of Meso - Neoproterozoic Era which disassembed recently. U - Pb isotopic age of Single granule Zircon is （ 837.8 ± 58 ） Ma, （ 842 ± 37 ） Ma , indicating that it was outcome of magmatic event of Jinningian Age. The geochemical character shows that it was formed in collision tectonic environment. The discovery of gueissic granite provides direct evidence for research in - depth of Qlian Orogenic belt basement of Presinian period, and reveds that there exist the collision - orogenesis of Jinningian Age.

关 键 词：中祁连 晋宁期花岗岩 地质特征 U—Pb同位素年龄 

分 类 号：P588.1[天文地球—岩石学]