【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。更多还原

【Abstract】 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 gneissic 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.更多还原