辽宁海城－大石桥－吉洞地区早元古代花岗岩

通过对海城－大石桥－古洞地区早元古代花岗岩的详细研究，将其构造形迹组合划分为同就位原生构造和就位后的次生构造。地球化学研究表明花岗岩具有分离结晶演化特征，属典型的裂谷型花岗岩。就位机制是在辽吉裂谷演化中晚期，在区域拉伸环境下首先在东部以顶蚀方式就位于辽河群底部，而后沿早期拉伸作用形成的基底与盖层之间的拆离带同构造顺层向西北部就位。

PALAEOPROTEROZOIC GRANITE IN HAICHENGDASHIQIAO-JIDONG AREA, EASTERN LIAONING

According to the detail studies of Palaeoproterozoic granite in Haicheng-DashiqiaoJidong area, the structure assemblages of the granite have been divided into syn-emplacement structures and post-emplacement structures. Geochemical features of the granite suggest that it is a typical rift-type granite with the evolution of fractional crystallization. During the middle-late stage of Liao-Ji rift evolution and in the enviroment of regional extension,the magma of granite intruded into the bottom of Liaohe Group in the east, and then in thenorthwest, the magma syntectonically and beddingly emplaced along the decollement formedbetween basement and cover owing to the extension in the early stage.