南祁连党河南山花岗岩类特征及其构造环境  

Granitoids Characteristics and Tectonic Setting of Danghenanshan Area in South Qilian Mountains

作　　者：刘志武[1] 王崇礼[2] 石小虎[3] 

机构地区：[1]西北大学地质学系,陕西西安710069 [2]长安大学国土资源部成矿作用及其动力学开放研究实验室,陕西西安710054 [3]长庆油田勘探开发研究院,陕西西安710021

出　　处：《现代地质》2006年第4期545-554,共10页Geoscience

基　　金：国土资源部定向科研项目;国土资源部成矿作用及其动力学开放研究实验室基金项目

摘　　要：党河南山地区地处南祁连重要成矿带,区内花岗岩类岩体包括扎子沟岩体、鸡叫沟岩体及贾公台岩体,伴有不同程度的金、铜矿化。扎子沟岩体主要由花岗闪长岩组成,侵位于震旦纪火山岩系。鸡叫沟岩体主要由石英二长闪长岩组成,贾公台岩体主要由斜长花岗岩组成,两者侵位于奥陶纪碎屑岩系。3个岩体Rb-Sr等时线年龄分别为(510.85±14)M a、(395.06±51)M a及(355±91)M a,前者对应于早—中寒武世,后二者对应于志留纪—泥盆纪。3个岩体均属于钙碱性花岗岩系列,其中扎子沟岩体属于该系列的中钾花岗闪长岩系列,鸡叫沟岩体属于高钾二长岩系列,贾公台岩体属于低钾奥长花岗岩系列。综合岩相学、岩石化学及微量元素和稀土元素的地球化学特征,区内3个岩体均形成于I型活动陆缘环境,为中南祁连造山带加里东期构造岩浆活动的产物。Danghenanshan area lies in South Qilian Mountains which is a great metallogenic belt. In this area, the granitoids are composed of Zhazigou pluton, Jijiaogou pluton and Jiagongtai pluton and all related to mineralization of gold and copper. Zhazigou pluton is mainly constituted by granodiorite and intrudes Sinian Period volcanic rocks. Jijiaogou pluton is mainly constituted by quartz monzodiorite, Jiagongtai pluton is mainly constituted by plagiogranite, and they both intrude Ordovician Period clastic rocks. The Rb-Sr isochron ages of the three plutons are （510. 85 ± 14）Ma, （395.06 ±51 ）Ma and （355 ±91 ）Ma respectively, the former formed during early-middle Cambrian Period, the latter two formed during Silurian Period and Devonian Period. This three plutons all correspond to calc-alkaline series. In this series, Zhazigou pluton belongs to middle-potassium granodiorite series, Jiagongtai pluton belongs to high-potassium monzonite ones, and Jiagongtai pluton belongs to low-potassium trondhjemite ones. The granitoid characteristics of lithofacies, petrochemistry, trace elements and REE geochemistry indicate that this three plutons are all Ⅰ-type granitoids, formed in active continental margin, and are the results of tectonic movement and and magmatism of middle-south Qilian Mountains during Caledonian.

关 键 词：党河南山 花岗岩类 岩相学 同位素 地球化学 构造环境 南祁连 

分 类 号：P588.121[天文地球—岩石学]