新疆北山地区平梁子北一带晚石炭世花岗岩形成环境探讨

Discussion of Formation Environment in Late Carboniferous Granitoids in Beishan area,Xinjiang Province

平梁子一带的晚石炭世花岗岩类,侵入期次繁多,岩性多样,主要有闪长岩、石英闪长岩、花岗闪长岩、二长花岗闪长岩等,受区域断裂构造控制。运用花岗岩类微量元素的R1-R2判别图解、Hf-Rb/10-Ta×3三角图解、Rb-Y+Nb和Nb-Y判别图解,确定本区花岗岩类来自壳幔混源,形成于岛弧环境,与华力西早期裂谷阶段性挤压闭合相关连。

Late Carboniferous granitoids have varied lithology with diorite, quartz diorite, granodiorite, two feldspar granodiorite, accompanied with frequent phase with intrusive activities. The use of trace elements of granitoids R1 - R2 discrimination diagram, Hf- Rb/10 -Ta ×3 triangular diagram, Rb -Y ＋ Nb and Nb -Y discrimination diagram , the authors determine the area of granitoids from the crust - mantle mixed source formed in an island arc environment, associated with the early rifting of the Variscan stage.