青海南部曲麻莱县加容检德工卡侵入岩序列特征及其构造环境

Geochemistry and tectonic setting of the Jiarongjiandegongka intrusive rocks in Qumarleb,Qinghai

加容检德工卡侵入岩序列由石英闪长岩-英云闪长岩-花岗闪长岩-正长花岗岩组成。岩石化学成分表现为从中基性到酸性的演化及岩浆向富硅、富碱方向演化。稀土元素特征表现为轻稀土元素富集;微量元素特征表现为富集大离子亲石元素Rb、K、Ba、Th,而Sr、Nb、Ta略显亏损,Ti、P较强亏损。构造环境为同碰撞花岗岩,时代为早白垩世。

The intrusive sequences in Jiarongjiandegongka, Qinghai consist of quartz diorite, tonalite, granodiorite and syenogranite. The lithochemical compositions display the evolution from intermediate, basic to acidic rocks, and the magmas are rich in silica and alkali. The geochemical signatures are characterized by the enrichment of LREE, enrichment of large ion lithophile elements such as Rb, K, Ba and Th, slight depletion of Sr, Nb and Ta, and strongly depletion of Ti and P. The tectonic setting of the Jiarongjiandegongka intrusive rocks are assigned to syn-collision granites, and may be traced back to the Early Cretaceous.