地质科技情报2011，Vol.30Issue(3)：57-64,8.
内蒙古锡林浩特、林西地区三叠纪过铝质花岗岩的成因及构造意义
Petrogenesis and Tectonic Significance of Triassic Peraluminous Granitoids in Xilinhaote and Linxi Area, Inner Mongolia
摘要
Abstract
This article newly plots out two belts of nearly east-westward peraluminous granitoids in Xilin-haote and Linxi area, Inner Mongolia, the middle of Xin'an-Mongolia orogen, North China. Zircons from four granite samples were dated using LA-ICP-MS method. A weighted average apparent age of (248. 3+. 7. 1) -(238. 1 + 7. 4) Ma(206Pb/238U) is attained, equal to the Indosinian era, which represents the crystal age of the source rocks of granitoids. The rock association of the peraluminous granitoids is granodiorite and monzogranite. Petrographically, with light grey to grey color and low dark minerals, some of the granitoid samples contain aluminous-rich minerals, such as muscovite and tourmaline, presenting the features of leucogranitoids. The petrochemical and geochemical characters of the peraluminous granitoids show peraluminous high-k calc-alkaline, with high SiO2, low MgO, FeOT, CaO, high K2O content and K2O/Na2O ratio, which are similar to the typical S-type granitoids. Most of the peraluminous granitoids are plotted in syn-collision granitoids field on the main and trace elements tectonic discrimination diagram of the peraluminous granitoids. Combining with the research advances in microfossils, ophiolites and granitoids in this area,the author concludes that Xing'an- Mongolian orogenic belt is a multicycle orogenic belt, the Triassic peraluminous granitoids are the products of the last stage during the late Hercynian-Indosinian cycle, namely, the Siberia Plate and the North-China Plate was convergent in Trias.关键词
三叠纪/过铝质/S型花岗岩/锡林浩特/林西Key words
Triassic/peraluminous/S-type granitoid/Xilinhaote/Linxi分类
天文与地球科学引用本文复制引用
叶栩松1a,2,廖群安1b,葛梦春1b..内蒙古锡林浩特、林西地区三叠纪过铝质花岗岩的成因及构造意义[J].地质科技情报,2011,30(3):57-64,8.基金项目
中国地质调查局华北地区基础地质调查项目(1212010510507) （1212010510507）
