摘要
豫西吉家洼金矿位于熊耳山金多金属矿集区西部,是一构造蚀变岩-石英脉型金矿床。矿体产于近南北向断裂带中,在倾向上呈"Y"字型分布,矿化以细脉-网脉状、浸染状黄铁矿化蚀变岩型金矿为主,其次为石英脉型金矿。热液成矿过程包括4个矿化阶段,黄铁矿-石英阶段(Ⅰ)、石英-黄铁矿阶段(Ⅱ)、石英-多金属硫化物阶段(Ⅲ)和石英-碳酸盐阶段(Ⅳ)。本次工作对吉家洼金矿床主要成矿阶段(Ⅲ)的闪锌矿进行了Rb-Sr同位素测年研究,以限定成矿时代。结果获得Rb-Sr等时线年龄为118.2±2.4Ma,表明矿床形成于早白垩世。该年龄与熊耳山地区中的庙岭、祁雨沟、公峪等金矿床的成矿年龄基本一致,对于整个熊耳山地区的金矿成矿年龄具有一定的约束意义。锶-铅同位素研究结果显示,吉家洼金矿的成矿物质为壳幔混源,新太古界太华群基底及其重熔形成的花岗岩体可能为铅同位素的主要物源。我们认为,吉家洼金矿床是熊耳山地区在早白垩世区域性强烈的构造-岩浆-流体活动事件的产物,是整个中国东部金的大规模成矿作用的组成部分。
The Jijiawa gold deposit,located in the western part of the Xiong＇ershan gold polymetallic ore district,Henan Province,is typical of tectonically altered rock-quartz vein-type gold deposit.Orebodies are hosted mainly within nearly NS-trending fault zone and are distributed in the form of ＂Y＂shape.Mineralization is dominated by vein-veinlet and disseminated pyritized altered rock gold deposits,with minor being quartz vein-type gold deposits.The hydrothermal ore-forming process can be divided into four stages：pyrite-quartz vein stage（I）,quartz-pyrite vein stage（II）,quartz-polymetallic sulfides stage（III）,and quartz-carbonate vein stage（IV）.This study carried out Rb-Sr isotopic dating for the sphalerites from main mineralization stage of the Jijiawa Au deposit to restrain the ore-forming time.The yielded isochron age of 118.2±2.4 Ma suggests that the deposit was formed in Early Cretaceous.The age is basically in agreement with that of Miaoling,Qiyugou,Gongyu and other gold deposits in the Xiong＇ershan area,which is of significance in constraining the ore-forming age in the Xiong＇ershan area.Sr and Pb isotope analysis shows that the Jijiawa Au deposit had a mixing origin of the materials from crust and mantle,with the Early Cretaceous granite likely contributing main metallogenic materials.In the context of regional geology,we suggest that the Jijiawa Au deposit was the product of the regional intensive tectonomagmatic-fluid activity in the Xiong＇ershan area in Early Cretaceous,and it is also a component part of the large-scale gold mineralization in eastern China.
作者
张兴康
叶会寿
颜正信
李思伟
樊玉朋
张福斌
ZHANG Xingkang1,2 , YE Huishou2 , YAN Zhengxin3 , LI Siwei1 , FAN Yupeng1, ZHANG Fubin1 ）(1 Hebei Institute of Geological Survey, Shijiazhuang, 050081; 2 MLR Key Laboratory of Metallogeny and Mineral Assessment, Institute of Mineral Resources, Chinese Academy of Geological Sciences, Beijing , 100037 3 No. 1 Institute of Geological and Mineral Resources Survey of Henan, Luoyang, Henan, 4710)
出处
《地质学报》
EI
CAS
CSCD
北大核心
2018年第5期1003-1018,共16页
Acta Geologica Sinica
基金
中国地质科学院基本科研业务费项目(编号YYWT-201713)
国土资源部成矿作用与资源评价重点实验室开放研究项目(编号ZS1314)联合资助成果
