北昆仑莫孙都勒格晚二叠世石英闪长岩地球化学特征及锆石U-Pb年龄

Geochemical Characteristics and Zircon U-Pb Age of the Quartz Diorite of Late Permianin the Northern Kunlun MosundulegeArea

位于北昆仑莫孙都勒格东一带的侵入岩发育较为广泛,岩石类型主要为石英闪长岩。其中地球化学数据表明这些岩体属偏铝-钙碱性系列岩石;LREE富集、HREE亏损,轻重稀土分馏明显;岩石中含较高含量的大离子亲石元素(Rb、Ba、Sr)。相反,而高场强元素(Nb、Ta、Hf)的含量则普遍较低;且锆石U-Pb年龄测年结果显示,该石英闪长岩的206Pb/238U年龄为251.4±1.2Ma,表明该岩体为晚二叠世岩浆活动期产物。根据结果显示,并结合区域地质演化特征研究,认为该侵入岩形成环境为火山弧环境。

The intrusive rocks in mosundulegedong area of North Kunlun are widely developed,and the rock types are mainly quartz diorite.These rock masses belong to the series of metaluminium-calcium-alkaline rocks,LREE enrichment,HREE loss,heavy and heavy rare earths,and the rocks contain high content of large ionic lithophiles(Rb、Ba、Sr).Conversely,the content of high field strength elements(Nb、Ta、Hf)is generally low.And the 206Pb/238U age of quartz diorite is 251.4±1.2Ma,indicating that the rock is a product of late Permian magmatic activity.According to the results and the study,The formation environment of intrusive rocks is volcanic arc.