A Paleozoic mercury mineralisation event in South China:In situ U-Pb dating and chemical compositions of calcite from the Jianyan Hg deposit  

作　　者：Kai LUO Jiaxi ZHOU Alexandre CUGERONE Meifu ZHOU Yuexing FENG Zhongguo JIN Jianxin ZHAO 

机构地区：[1]Key Laboratory of Critical Minerals Metallogeny in Universities of Yunnan Province,School of Earth Sciences,Yunnan University,Kunming 650500,China [2]School of Earth and Environmental Sciences,The University of Queensland,Brisbane QLD 4072,Australia [3]State Key Laboratory of Ore Deposit Geochemistry,Institute of Geochemistry,Chinese Academy of Sciences,Guiyang 550081,China [4]Department of Earth Sciences,University of Geneva,Geneva 1205,Switzerland [5]Southern Marine Science and Engineering Guangdong Laboratory,Zhuhai 519000,China [6]Non-Ferrous Metals and Nuclear Industry Geological Exploration Bureau of Guizhou,Guiyang 550005,China

出　　处：《Science China Earth Sciences》2023年第8期1877-1891,共15页中国科学（地球科学英文版）

基　　金：financially supported by the National Natural Science Foundation of China(Grant Nos.41872095,U1812402,and 42172082);the Research Startup Project of Yunnan University(Grant No.YJRC4201804);the Talents Program Project of Yunnan Province(Grant No.YNQR-QNRC-2018-104)to Jiaxi ZHOU。

摘　　要：The ages of hydrothermal Hg deposits are difficult to constrain because of the lack of suitable minerals for dating.The South China low-temperature metallogenic domain hosts numerous Hg deposits,including the Jianyan Hg deposit that is composed mainly of cinnabar and calcite.There are two stages of calcite in the deposit:syn-ore calcite(Cal-Ⅰ)and post-ore/barren calcite(Cal-Ⅱ).Cal-Ⅰis mainly euhedral-subhedral and fine-grained,has homogeneous grey luminescence,and is associated with cinnabar.Subhedral-anhedral Cal-Ⅱcrosscuts Cal-Ⅰand is relatively coarse-grained.The syn-ore Cal-Ⅰhas high U contents(0.1–1.3 ppm)and U/Pb ratios(up to 4.2),and is thus suitable for U-Pb dating.Using a laser ablation-inductively coupled plasma-mass spectrometer equipped with ion counters,we obtained a U-Pb age of 426.3±5.7 Ma(MSWD=1.5)for CalI.This age is interpreted to represent the timing of Hg mineralisation at Jianyan and is similar to ages of 440–400 Ma reported for many carbonate-hosted Pb-Zn and Ba-F deposits in South China.Based on the present results in combination with existing geochemical and geochronological data,we infer that these deposits belong to a Paleozoic Hg-Pb-Zn-Ba-F mineralisation system that was controlled by Caledonian tectonism.

关 键 词：In situ calcite U-Pb dating Paleozoic Hg mineralisation Caledonian tectonism Jianyan Hg deposit South China 

分 类 号：P612[天文地球—矿床学]