地学前缘 ›› 2019, Vol. 26 ›› Issue (5): 96-105.DOI: 10.13745/j.esf.sf.2019.8.15

• 矿床地质地球化学 • 上一篇    下一篇

西秦岭天水范家山夕卡岩型铜金矿床地质特征及成因探讨

高作宇，刘云华，韩一筱，雷万杉，邓楠   

  1. 1. 长安大学 地球科学与资源学院, 陕西 西安 710054
    2. 自然资源部岩浆作用成矿与找矿重点实验室, 陕西 西安 710054
  • 收稿日期:2018-05-30 修回日期:2019-08-22 出版日期:2019-09-28 发布日期:2019-09-28
  • 通讯作者: 刘云华(1965—)，男，博士,研究员，主要从事矿产地质专业教学与研究工作。
  • 作者简介:高作宇(1992—)，男，博士研究生，地球化学专业。E-mail：616718538@qq.com
  • 基金资助:
    国家自然科学基金项目(41872219);自然资源部中国地质调查局地质调查项目(DD20190060)

Geological characteristics and genesis of the Fanjiashan copper and gold skarn deposit of western Qinling in Tianshui, Gansu

GAO Zuoyu,LIU Yunhua,HAN Yixiao,LEI Wanshan,DENG Nan   

  1. 1. School of Earth Science and Resources, Chang'an University, Xi'an 710054, China
    2. Key Laboratory for the Study of Focused Magmatism and Giant Ore Deposits, Ministry of Natural Resources, Xi'an 710054, China
  • Received:2018-05-30 Revised:2019-08-22 Online:2019-09-28 Published:2019-09-28
  • Supported by:
     

PDF (PC)

237

摘要： 范家山铜金矿位于西秦岭北成矿亚带，温泉复式花岗岩天水斑岩夕卡岩钼铜金矿带的核心位置。矿床地质特征表明：范家山铜金矿体主要受岩体与围岩接触带以及岩体附近的断裂破碎带的控制，以金铜矿化为主，围岩蚀变为夕卡岩化、角岩化及硅化、绢英岩化等。范家山铜金矿床主矿脉包裹体温度、盐度及H-O同位素研究显示，主成矿流体的盐度(S)为2.0%～11.0%(w(NaCl)eq)，均一温度为120～345 ℃，主要集中在150～280 ℃范围，具有中温和中低盐度的特征，为岩浆水和大气降水的混合。成矿花岗斑岩锆石U-Pb年龄为(248.3±1.9) Ma(MSWD=0.67, N=9)，表明成矿活动发生在印支早期。结合区域构造背景，范家山铜金矿为印支期早期陆陆碰撞导致地壳加厚背景下的夕卡岩型矿床，深部具有斑岩型成矿的潜力。

 

关键词: 铜金矿, 夕卡岩型, 范家山, 西秦岭

Abstract: The Fanjiashan copper and gold mine of the metallogenic subzone is located in the north of West Qinling Mountains, at the core of the Wenquan composite granite-Tianshui porphyry-skarn molybdenum copper and gold zone. The geological characteristics of the deposit show that the Fanjiashan copper and gold mine is dominated by gold and copper mineralization and mainly controlled by the rock-wall rock contact belt and fracture zone surrounding the nearby rocks. The wall rocks feature alterations by skarnization, amphibolitization, silicification and sericitization. We studied the temperature, salinity and H-O isotope of mother lode inclusions in the Fanjiashan copper and gold deposit. The results show that the main metallogenic fluid has a salinity (S) of 2.0%11.0%(w(NaCl)eq) and a homogeneous temperature of 120 – 345 ℃(mostly in 150 – 280 ℃). This medium temperature and medium to low salinity fluid can be characterized as a mixture of magmatic water and atmospheric precipitation. The zircon U-Pb age of metallogenic granite porphyry is 248.3±1.9 Ma (MSWD=0.67, N=9), indicating mineralization in early Indosinian. Based on the regional tectonic setting, the Fanjiashan copper and gold mine is a skarn deposit, arising from the crust thickening during the early-stage of Indosinian collision, and has deep ground porphyry mineralization potential.

Key words: copper and gold mine, skarn type, Fanjiashan, West Qinling Mountains

中图分类号: