摘要
冷湖花岗岩体由花岗闪长岩和二长花岗岩组成，岩体中发育较多的辉绿岩墙和花岗闪长斑岩岩墙。岩石的常量、稀土、微量元素地球化学研究表明：花岗岩类和脉岩类为同源岩浆分异演化而成，Rb-Sr、Sm-Nd同位素特征反映其源岩来自地幔。地球化学判别图解得出，冷湖花岗岩类属I型花岗岩，早期的花岗闪长岩形成于岛弧环境，与柴达木板块、南祁连板块的碰撞有关；晚期的二长花岗岩形成于板块碰撞隆起环境，与阿尔金大型走滑断裂的活动有关。
：The Lenghu granitoids consist of granodiorite and monzonitic granite.There exist many diabase and granodioritic porphyry dikes in the intrusion.Major and minor element， REE and trace element geochemistry of the rocks show that the granitoids and dike rocks originated by differentiation of cogenetic magma.Rb-Sr and Sm-Nd isotope data indicate that they were derived from the mantle.Trace element discrimination diagrams show the following： the Lenghu granitoids belong to I-type granites； the early-stage granodiorite intruded in an island-arc environment and was related to the collision of the Qaidam plate and South Qilian plate， while the late-stage monzonitic granite formed in a plate collision and uplift environment and was related to the activity of the Altun strike-slip fault．
出处
《中国区域地质》
CSCD
北大核心
2001年第1期73-81,共9页
Regional Geology of China
基金
国家自然科学基金!(49772106
49732070)
地矿部"九五"重点基础项目!(9501106)
国家305项目06-04专题资助
关键词
花岗岩
脉岩
地球化学
构造环境
柴达木盆地
成因
granitoids； dike rocks； geochemistry； tectonic environment； Lenghu，Qinghai
