投稿时间：2023-12-17
修订日期：2024-03-12
网络发布日期：2024-06-26
中文摘要:行洛坑超大型钨矿床位于福建省宁化县东部，是武夷山成矿带内最大的钨矿床，具有储量大、品位低、黑钨矿与白钨矿资源量相近的特点。白钨矿作为含钨矿物，其形成年龄可以代表矿床的成矿时代，其地球化学特征反映了成矿作用环境和过程。文章在对行洛坑钨矿床钨矿脉特征、黑钨矿与白钨矿赋存状态开展调查的基础上，挑选白钨矿单矿物进行了Sm-Nd等时线测年和微量元素测试。研究结果显示，白钨矿结晶年龄为（142.6±2.8）Ma，略小于黑钨矿原位U-Pb年龄（150.5±8.1）Ma和石英流体包裹体Rb-Sr等时线年龄（147.5±2.9）Ma，与矿区隐伏岩体成岩年龄143.5~149.5 Ma在误差范围内完全吻合，也与矿物结晶世代关系吻合，都属于晚侏罗世的产物，说明钨成矿与隐伏岩体成岩近于同时或稍晚发生。白钨矿中微量及稀土元素特征显示第一世代成矿流体中Eu3+ < < Eu2+，指示成矿流体为还原性流体；第二世代成矿流体中Eu3+ > > Eu2+，指示成矿流体为氧化性流体。行洛坑钨矿成矿与华南中生代大规模成矿作用及其大地构造背景和动力学环境密切相关。
Abstract:The super giant Xingluokeng tungsten deposit is located in the eastern part of Ninghua County, Fujian Province. It is the largest tungsten deposit in the Wuyishan metallogenic belt, and it has the characteristics of large reserves, low grade, similar resources of wolframite and scheelite. As a tungsten-bearing mineral, the formation age of scheelite can represent the metallogenic age of the deposit, and its geochemistry characteristics reflect the metallogenic environment and process. Based on the investigation of the characteristics of tungsten veins and the occurrence of scheelite and wolframite in the Xingluokeng tungsten deposit, the separated scheelite were used for Sm-Nd isochron dating and trace element testing. The results show that the crystallization age of scheelite is （142.6±2.8）Ma, which is slightly smaller than the in situ U-Pb age of （150.5±8.1）Ma of wolframite and the Rb-Sr isochronal age of quartz fluid inclusions of （147.5±2.9）Ma, it is consistent with the forming age of 143.5~149.5 Ma of the concealed intrusion within errors and with the temporal relation of mineral crystallization, both belong to the product of Late Jurassic magmatic activity, indicating that tungsten mineralization has the same age as or a little later than the concealed intrusive rock body. The characteristics of trace and rare earth elements in scheelite show that the first generation ore-forming fluid contains Eu3+ < < Eu2+, indicating that the stage 1 ore-forming fluid is reductive fluid, and the second generation ore-forming fluid contains Eu3+ > > Eu2+, indicating that the ore-forming fluid evolved to oxidizing fluid in stage 2. The mineralization of the Xingluokeng tungsten deposit is closely related to the Mesozoic large-scale mineralization in South China with specific tectonic setting and dynamic environment.
keywords:scheelite metallogenic age trace element characteristics characteristics of ore-forming fluids Xingluokeng tungsten deposit
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基金项目:本文得到国家重点研发项目（编号：2016YFC0600207、2017YFC0602602）和院所长基金项目（编号：JYYWF20180602）联合资助
引用文本：
陈柏林,申景辉,高允,王光华.2024.福建行洛坑钨矿床白钨矿Sm-Nd等时线年龄及微量元素地球化学特征[J].矿床地质,43(3):463~477CHEN BaiLin,SHENG JingHui,GAO Yun,and WANG GuangHua.2024.Sm-Nd isochronal age and trace element geochemistry characteristics of scheelite in Xingluokeng tungsten deposit, Fujian Province[J].Mineral Deposits43(3):463~477
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