青海同仁相玉沟岩体地球化学特征及成因

Geochemical Characteristics and Origin of Xiangyugou Rock in Tongren County Qinghai Province

青海同仁相玉沟岩体的岩石组合为二长花岗岩、黒云花岗闪长岩,U-Pb同位素年龄为246.6±6.2 Ma,时代属于三叠世。根据相玉沟岩体的岩石学、主量元素、微量元素及稀土元素分析结果,该岩体为富钾贫钠的过铝钙碱性岩石系列,成因类型主要为S型的过渡类型,早期为活动大陆边缘产物,晚期为大陆碰撞褶皱带内过铝质的钙碱性岩类。

The rock combination of Xiangyugou rock mass in Qinghai Tongren is a monzonitic granite and a Jinyun granodiorite. The U-Pb isotope age is 246.6±6.2 Ma, and the age belongs to the Triassic. According to the petrology and the main elements, trace elements and rare earth elements of the Xiangyugou rock mass, the rock mass is a series of potassiumand sodium-depleted peraluminous calcium-alkaline rocks. The genetic type is mainly the S-type transition type, and the early stage is active. The continental marginal product, in the late stage, is an aluminum-alkaline calc-alkaline rock in the continental collision fold zone.