投稿时间：2018-09-05
修订日期：2019-03-31
网络发布日期：2019-12-24
中文摘要:柞水-山阳矿集区位于秦岭造山带中部，区内矿产资源丰富，金矿找矿近年来不断取得突破，发现了多个大-中型金矿床，然而区内金矿成矿时代、成矿地质背景一直存在争议，直接制约矿集区金矿床找矿工作。夏家店金矿床是该区大型金矿床，矿体受断裂构造控制，金矿石类型有角砾岩型、碎裂岩型、糜棱岩型3种。围岩蚀变强烈，主要由硅化、方解石化、绢云母化、高岭土化、萤石化、重晶石化等，与金成矿关系最密切的是硅化、方解石化、萤石化。热液成矿期可划分为石英阶段、石英-方解石-萤石-硫化物阶段、方解石阶段。文章选取夏家店金矿床主成矿期的方解石、萤石等矿物进行了Sm-Nd同位素测试工作，获得等时线年龄为（139.64±0.98）Ma，表明成矿时代为晚侏罗世。结合区域构造-岩浆成矿作用特征，认为夏家店金矿床成矿作用与晚侏罗世-早白垩世构造-岩浆事件有关。据此将柞水山阳矿集区金矿床成矿年龄厘定在140Ma左右，为秦岭造山带伸展的地球动力背景下构造-岩浆热液演化的产物。通过与区内晚侏罗世-早白垩世构造-岩浆成矿事件对比，文章首次提出柞水-山阳矿集区存在140 Ma左右的金矿床成矿事件，为下一步在柞水-山阳矿集区开展金矿床勘查工作提供了重要依据。
Abstract:The Zhashui-Shanyang ore concentration area is located in the middle of the Qinling orogenic belt. Mineral resources are abundant in the area. The gold ore prospecting has made breakthroughs in recent years, and many large-medium-sized gold deposits have been discovered. However, the gold mineralization age and formation in the area as well as the geological background of the deposits have been controversial, which directly restricts the prospecting of gold deposits in the ore concentration area. The Xiajiadian gold deposit is a large gold deposit in the area. The orebody is controlled by fault structure. The gold ore types are breccia type, fragmented rock type and mylonite type. The surrounding rock has experienced strong alterations, mainly silicification, pyrolysis, seric-itization, kaolinization, fluoritization, and heavy-grained petrochemical alteration. The alterations most closely related to gold mineralization are silicification, petrochemical alteration, and fluoritization. The hydrothermal mineralization period can be divided into quartz stage, quartz-calcite-fluorite-sulfide stage and calcite stage. In this study, Sm-Nd isotope test was carried out on minerals such as calcite and fluorite in the main mineralization period of the Xiajiadian gold deposit. The isochron age is(139.64±0.98) Ma, indicating that the ore-forming age is Late Jurassic. Combined with the characteristics of regional tectonic-magmatic mineralization, it is believed that the mineralization of the Xiajiadian gold deposit was related to the late Jurassic-early Cretaceous tectonic-magmatic events. On such a basis, the ore-forming age of the gold deposit in the Zhashui-shanyang ore district should be about 140Ma, suggesting a product of the tectonic-magmatic hydrothermal evolution of the Qinling orogenic belt. Compared with the late Jurassic-Early Cretaceous tectonic-magmatic mineralization events in the area, the authors present for the first time a gold deposit ore event that took place at about 140 Ma in the Zhashui-Shanyang ore concentration area, and this understanding provides an important basis for the further exploration of gold deposits in the Zhashui-Shanyang ore concentration area.
keywords:geochemistry Sm-Nd isotope metallogenic age Xiajiadian gold deposit Zhashui-Shanyang ore concentration area Qinling orogenic belt
文章编号：
中图分类号：P618.67
文献标志码：
基金项目:本文得到中国地质调查局"全国重要矿集区找矿预测"子项目（编号：DD2016005221）和"矿集区矿产调查及深部找矿预测"子项目（编号：DD2019057009）联合资助
引用文本：
刘凯,王瑞廷,樊忠平,任涛,李剑斌,赵亮,赵晓龙,肖鹏辉.2019.秦岭造山带柞水-山阳矿集区夏家店金矿床成矿时代及其地质意义[J].矿床地质,38(6):1278~1296LIU Kai,WANG RuiTing,FAN ZhongPing,REN Tao,LI JianBin,ZHAO Liang,ZHAO XiaoLong,XIAO PengHui.2019.Metallogenic age of Xiajiadian gold deposit in the Zhashui-Shanyang ore concentration, Qinling orogenic belt and its geological significance[J].Mineral Deposits38(6):1278~1296
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