内蒙古金厂沟梁金矿床成矿时限与动力学背景探讨  

Mineralization timing and geodynamic background of the Jinchanggouliang gold deposit in Inner Mongolia

作　　者：莫凌超 刘福林 张长征 贺所明 李达 常龙广 杨志明[1] MO LingChao;LIU FuLin;ZHANG ChangZheng;HE SuoMing;LI Da;CHANG LongGuang;YANG ZhiMing(Institute of geology,Chinese Academy of Geological Sciences,Beijing 100037,China;Institute of Mineral Resources Research,Chinese Metallurgical Geology Bureau,Beijing 101300,China;Inner Mongolia Jintao Co.,Ltd,Aohan 024327,China)

机构地区：[1]中国地质科学院地质研究所,北京100037 [2]中国冶金地质总局矿产资源研究院,北京101300 [3]内蒙古金陶股份有限公司,敖汉024327

出　　处：《岩石学报》2021年第6期1799-1812,共14页Acta Petrologica Sinica

基　　金：中国黄金集团公司科研项目(W1502)资助。

摘　　要：华北克拉通北缘是中国重要的金成矿带之一,分布着数十个大中型金矿床,但这些矿床的形成时代及成因类型尚存争议。位于内蒙古赤峰市境内的金厂沟梁是该带最为重要的大型金矿床,其与二道沟和长皋沟金矿床围绕130~122Ma的西对面沟岩体分布。该矿床矿体呈脉状产出,矿脉多赋存在太古代变质岩中,少量产于安山玢岩中,在矿区南部可见矿脉被粗面安山岩切穿,指示成矿发生在安山玢岩之后,粗面安山岩之前。两套岩浆岩的锆石LA-ICP-MS U-Pb定年结果揭示,岩浆结晶年龄分别为129.4±0.9Ma和124.0±0.5Ma,限定金厂沟梁金矿床成矿作用发生在129~124Ma之间,与西对面沟岩体侵位年龄一致,暗示两者具有成因关系,也反映矿床形成于早白垩世中国东部大规模岩石圈减薄的陆内伸展环境。The northern margin of the North China Craton is one of the important gold metallogenic belts in China.There are dozens of large and medium-sized gold deposits,but the age and genetic type of these deposits are still controversial.Jinchanggouliang,located in Chifeng City,Inner Mongolia,is the most important large gold deposit in the belt.It is distributed around the Xiduimiangou intrusion(crystallization age:130~122 Ma)with Erdaogou and Changgaogou gold deposits.The ore-veins of the deposit are mainly hosted in Archean metamorphic rocks,while a small amount of them occur in andesitic porphyrite,and are cut by trachyteandesite in the southern part of the mining area,which provided good constrains on the formation age of this deposit.Zircon LA-ICP-MS U-Pb dating results of the andesitic porphyrite and trachy andesite show that their crystallization ages are 129.1±1.3 Ma and 124.0±0.9 Ma,respectively,indicating Jinchanggouliang gold deposit was formed between 129~124 Ma.The metallogenesis of Jinchanggouliang deposit and emplacement of Xiduimiangou intrusion are almost simultaneous.It is inferred that this deposit may be formed in the extensional environment of large-scale lithospheric thinning in eastern China during the Early Cretaceous.

关 键 词：内蒙古 金厂沟梁金矿 成矿时限 伸展环境 

分 类 号：P588.144[天文地球—岩石学] P597.3[天文地球—地质学]