祁连党河南山北坡中-基性火山岩地质特征及时代  

GEOLOGICAL FEATURE AND CHRONOLOGY OF INTERMEDIATE-BASIC VOLCANIC ROCKS IN THE NORTHERN PART OF DANGHENANSHAN DISTRICTS IN QILIAN MOUNTAINS

作　　者：李厚民[1] 王崇礼[2] 刘继庆[2] 刘志武[2] 沈远超[3] 

机构地区：[1]中国地质大学(北京)地球科学与资源学院，北京100083 [2]长安大学，陕西西安710054 [3]中国科学院地质与地球物理研究所,北京100029

出　　处：《矿物岩石》2003年第1期1-4,共4页Mineralogy and Petrology

基　　金：“九五”国家科技攻关305项目(96-915-06-01A);国土资源部定向科研项目(98-16)

摘　　要：根据地质研究、区域对比 ,结合首次获得的 Rb- Sr等时线年龄数据 ,从祁连党河南山 (又称乌兰达坂山 )北坡原中奥陶统地层中厘定出晚震旦纪中 -基性火山岩系。根据这一新成果 ,认为该区中基性火山岩、斜长角闪岩基底以及侵入其中的扎子沟等花岗闪长岩岩基在大地构造分区上应划归中祁连地块 ;晚震旦纪该区无疑有过扩张、地壳减薄的地质事件 ,震旦纪晚期有过挤压闭合事件。By geological study, regional correlation and our first Rb Sr isochronic dating, we suggest that the intermediate basic volcanic rocks which were before considered belonging to Ordovician in the northern part of Danghenanshan districts in Qilian Mountains, Gansu province, belong to late Sinian. On this basis, we suggest that these media base volcanic rocks belong to late Sinian, that the volcanic rocks and its basement(plagioamphibolite) and Zhazigou granodiorite bodies are in middle Qilian block, and that this district had undoubtful expanded and crustal thinned in late Sinian and extruded at the end of Sinian.

关 键 词：晚震旦纪 中-基性火山岩 RB-SR等时线年龄 党河南山 祁连 

分 类 号：P588.12[天文地球—岩石学] P588.14[天文地球—地质学]