关键词: 青龙村群, 锆石年龄, 二叠纪末期, 燕山早期

Abstract: Qinglongcun Group consists mainly of gneiss, amphibolite, fine-to coarse-grained schist and laminated marble. The geochemical features of Qinglongcun Group show their protolith belongs to calc-alkalic andesite-rhyolite series that were formed during crystallization differentiation of island arc basalt magma. It is suggested that the rock series constitute an island arc terrane within a rather wide accretion-collision zone along continental margin. The zircon U-Pb dating shows that the age from amphibolite of Qinglongcun Group is (274±6) Ma while the age of Lishugou granite is (187±3) Ma. It indicates that Qinglongcun Group metamorphosed at the end of Permian during the collision orogen event of northern margin of North China plate and the granite intruded into Qinglongcun Group at early Yanshan movement, which belongs to the results of postorogenic extension event.

Key words: Qinglongcun Group, zircon age, late Permian, early Yanshan movement