地学前缘 ›› 2019, Vol. 26 ›› Issue (5): 163-173.DOI: 10.13745/j.esf.sf.2019.9.2

• 矿床地质地球化学 • 上一篇    下一篇

豫西南高庄金矿床Re-Os定年及S-Pb同位素和REE示踪

张健，薛春纪，曹纪虎，彭姣   

  1. 1. 地质过程与矿产资源国家重点实验室; 中国地质大学(北京) 地球科学与资源学院, 北京 100083
    2. 河南省有色金属地质矿产局, 河南 郑州 450016
  • 收稿日期:2019-08-10 修回日期:2019-09-20 出版日期:2019-09-28 发布日期:2019-09-28
  • 通讯作者: 薛春纪(1962—)，男，教授，博士生导师，从事矿床学、矿产预测教学与研究工作。
  • 作者简介:张健(1988—)，男，博士，矿物学、岩石学、矿床学专业。E-mail: 995730784@qq.com
  • 基金资助:
    国家重点研发计划项目(2017YFC0601202)；国家自然科学基金项目(U1303292)；河南省有色金属地质矿产局科技创新项目“北秦岭造山带(河南段)银金多金属矿成矿规律及找矿方法研究(YSDK2014-01)”

Re-Os dating and S-Pb isotopic and rare earth elements analyses of the Gaozhuang gold deposit in southwestern Henan, China

ZHANG Jian,XUE Chunji,CAO Jihu,PENG Jiao   

  1. 1. State Key Laboratory of Geological Processes and Mineral Resources; School of Earth Sciences and Resources, China University of Geosciences (Beijing), Beijing 100083, China
    2. Henan Bureau of Non-ferrous Metals Geological and Mineral Resource, Zhengzhou 450016, China
  • Received:2019-08-10 Revised:2019-09-20 Online:2019-09-28 Published:2019-09-28
  • Supported by:
     

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摘要： 高庄金矿床是豫西南一处重要金矿，成矿时代、物质来源以及矿床成因类型尚不清楚。本文对高庄金矿石中载金矿物磁黄铁矿进行Re-Os测年，获得(137±2) Ma成矿年龄，表明金矿床为燕山晚期成矿。分别对载金矿物磁黄铁矿、容矿地层(二郎坪群火神庙组)和侵入岩体(堂坪岩体)进行了S、Pb和REE组成分析。矿石硫化物δ34SCDT值为-3.0‰～-1.5‰，平均值为-2.24‰，深源S特征明显，矿石S可能来源于容矿的二郎坪群火神庙组基性火山岩地层。矿石硫化物206Pb/204Pb、207Pb/204Pb、208Pb/204Pb的变化范围分别为17.106～17.505、15.469～15.602、37.835～38.194。堂坪岩体206Pb/204Pb、207Pb/204Pb、208Pb/204Pb的变化范围分别为18.244 3～19.238 2、15.594 8～15.693 5、38.504 2～39.616 3，二郎坪群火山岩206Pb/204Pb、207Pb/204Pb、208Pb/204Pb变化范围分别为18.176 8～18.669 2、15.607 1～15.801 9、38.375 9～39.080 9。矿石铅同位素组成与地层和岩体的岩石铅组成相近，表明岩体和地层都提供了成矿物质。矿石与二郎坪群火神庙组地层的REE球粒陨石标准化配分曲线都为平坦型。可见，豫西南高庄金矿形成于秦岭碰撞造山之后的燕山晚期陆内构造岩浆热液过程，成矿物质主要来源于矿体周围火山岩地层。

 

关键词: Re-Os测年, S-Pb同位素和REE示踪, 陆内成矿, 高庄金矿, 豫西南

Abstract: The Gaozhuang gold deposit is an important gold deposit in southwestern Henan Province and has been studied by other researchers. However, the metallogenic province and epoch as well as ore types of the gold deposit are still poorly understood. In this paper, we performed Re-Os dating of pyrrhotite in the Gaozhuang gold deposit. The determined Re-Os age was 137±2 Ma, indicating the deposit was formed in the Late Yanshan Epoch. We also analyzed S and Pb isotopic and REE compositions of the gold-bearing mineral (pyrrhotite), the host strata (the Huoshenmiao Formation of the Erlangping Group) and the intrusive rock (the pluton rock mass). The δ34SCDT  value of ore sulphide was between -3.0‰ and -1.5‰ with an average value of -2.24‰, which suggests that sulfur may come from the deep source since its δ34SCDT  value was close to that of the original mantle sulfur (0±3‰), and that the sulfur ore may originate from the surrounding volcanic rock strata. Ratios of 206Pb/204Pb, 207Pb/204Pb and 208Pb/204Pb for ore sulfides ranged in 17.10617.505, 15.46915.602 and 37.83538.194, respectively. The 206Pb/204Pb, 207Pb/204Pb and 208Pb/204Pb ratios for the Tangping intrusion ranged in 18.244319.2382, 15.594815.6935 and 38.504239.6163, respectively. And the 206Pb/204Pb, 207Pb/204Pb and 208Pb/204Pb ratios for the host strata were of 18.176818.6692, 15.607115.8019 and 38.375939.0809, respectively. The above almost indistinguishable Pb isotopic ratios and their variation trend for the ore-lead, host strata and intrusion suggest that the ore-forming material is provided by both the host strata and the intrusion. The chondrite normalized REE distribution curves of the ore minerals were very similar to those of the Huoshenmiao Formation of the Erlangping Group, and they were all flat. The above results allow us to propose that the Gaozhuang gold deposit was formed in the Late Yanshan Epoch in the intracontinental metallogenic stage after the Qinling collisional orogeny. And the ore-forming material of the Gaozhuang gold deposit mainly comes from the host strata.

Key words: Re-Os dating, S and Pb isotopic and REE tracing, intracontinental mineralization, Gaozhuang gold deposit, southwestern Henan, China

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