内蒙古赤峰金厂沟梁金矿区花岗岩类年代学、地球化学特征及其地质意义  

Geochronology and geochemistry of the granites from the Jinchanggouliang gold deposit area in the Inner Mongolia and its geological significance

作　　者：段培新[1] 李长民[2] 刘翠[1] 邓晋福[1] 赵国春[1] 

机构地区：[1]中国地质大学地球科学与资源学院,北京100083 [2]中国地质大学长城学院,保定071000

出　　处：《岩石学报》2014年第11期3189-3202,共14页Acta Petrologica Sinica

基　　金：中国地质调查局项目(1212011121075;1212010911028;12120114020901;1212011220921;1212011121266;12120113094100);973项目(2011CB808901);科技部国际科技合作项目(2010DFB23390)联合资助

摘　　要：本文对内蒙赤峰地区金厂沟梁金矿区内的金厂沟梁、西台子、对面沟花岗质岩体开展了相关研究。金厂沟梁岩体岩性主要为片麻状二长花岗岩,LA-ICP-MS锆石U-Pb测年结果为249.9±1.4Ma,为早三叠世。构造环境判别为大陆碰撞造山(CCG)。西台子岩体岩性为似斑状二长花岗岩,其LA-ICP-MS锆石U-Pb测年结果为216.7±1.8Ma,为晚三叠世,构造环境判别图解中位于后造山(POG)区域。对面沟岩体为早白垩世,其中心相岩性是石英二长斑岩,边缘相是石英二长岩,在构造环境判别图中均属于火山弧环境。结合区域地质资料和前人研究成果,推测古亚洲洋构造域在晚三叠世已到末期,从而进入大陆碰撞造山的末期陆内造山阶段。本文提出岩基对后期成矿的控制作用,认为早于成矿时期所形成的板状侵入体为后期成矿提供必要条件,较为合理的解释金厂沟梁地区金矿分布的成因,并可能具有普遍意义。This paper studies the granitic rocks of Jinchanggouliang,Xitaizi and Duimiangou in Chifeng area,Inner Mongolia.Jinchanggouliang granitic rocks are mainly composed of gneissose mozonitic granite,the zircon LA-ICP-MS U-Pb dating of it gave an age of 249. 9 ± 1. 4Ma,i. e.,Early Triassic. These rocks are all plotted in the area of CCG in the diagrams for discrimination of tectonic settings. Zircon LA-ICP-MS U-Pb dating of Xitaizi porphyritic mozonitic granite gave an age of 216. 7 ± 1. 8Ma,i. e.,Late Triassic. In the diagrams for discrimination of tectonic settings,they are plotted in the area of POG. Duimiangou granitic rocks are composed of beschtauite and quartz monzonite,which intruded in Early Cretaceous,the center phase are beschtauite,while the edge phase are quartz monzonite. In the diagrams for discrimination of tectonic settings,they are plotted in the VAG area. Combined with previous studies and the regional geology,in the Late Triassic,Paleo-Asian Ocean had been ending,and this area had stay in the end of a continental collision orogenic intra continental orogenic stage. This paper puts forward the controlling role of the batholith to the later mineralization, that the plate which is formed before the mineralization provides the necessary conditions for the later mineralization,it reasonably explains the distribution gold in the area of Jinchanggouliang gold field,and may have an universal significance.

关 键 词：金厂沟梁地区花岗岩 锆石U-PB年龄 三叠纪 岩基后成矿模式 内蒙古 

分 类 号：P588.121[天文地球—岩石学] P597.3[天文地球—地质学]