Microthermometry and Synchrotron Radiation X-ray Fluorescence Analysis of Fluid Inclusions in the Dongping Gold Deposit,Northern Margin of the North China Craton  

作　　者：WEI Hao CHU Haixia XU Jiuhua LI Dong FENG Yunlei ZHANG Guorui 

机构地区：[1]Hebei Key Laboratory of Strategic Critical Mineral Resources,Hebei GEO University,Shijiazhuang 050031,China [2]China University of Geosciences(Beijing),Beijing 100083,China [3]University of Science and Technology Beijing,Beijing 100083,China [4]East China University of Technology,Nanchang 330013,China

出　　处：《Acta Geologica Sinica(English Edition)》2023年第2期501-512,共12页地质学报（英文版）

基　　金：funded by a Natural Science Foundation of Hebei Province(Grant No.D2020403019);the Natural Science Foundation of Hebei Province(Grant Nos.D2020403101 and D2019403041);the Science and Technology Project of Hebei Education Department(Grant No.ZD2020134);the National Natural Science Foundation of China(Grant Nos.41702094 and 41672070);the Science and Technology Innovation Team Project of Hebei GEO University(Grant No.KJCXTD-2021-02)。

摘　　要：To shed light on the genesis of the Dongping deposit and reveal the behaviour of CO_(2),Au and other ore elements(e.g.,Cu,Fe,Zn,As,Sb,Co etc.)in ore-forming fluids,petrographic,microthermometric and synchrotron radiation X-ray fluorescence(SRXRF)analyses of fluid inclusions were conducted.The ore-forming fluid is characterized as an H_(2)O-CO_(2)-NaCl system with medium-high temperatures and low salinity.Four mineralization stages are identified,namely,feldsparquartz(stage 1);pyrite-white quartz(stage 2);sulfide-smoky grey quartz(stage 3);and carbonate-quartz(stage 4).Three types of inclusions were distinguished,based on fluid composition,phase assemblages and mode of homogenization.Type A:H_(2)O-rich fluid inclusions show 2 phases(liquid H_(2)O(LH_(2)O)+vapour H_(2)O(VH_(2)O))at room temperature and homogenize to the liquid phase.Type B:H_(2)O-CO_(2)fluid inclusions contain 2–3 phases(liquid H_(2)O(LH_(2)O)+vapour CO_(2)(VCO_(2));liquid H_(2)O(LH_(2)O)+liquid CO_(2)(LCO_(2)));liquid H_(2)O(LH_(2)O)+liquid CO_(2)(LCO_(2))+vapour CO_(2)(VCO_(2)))at room temperature and homogenized to the liquid H_(2)O phase.Type C:H_(2)O-CO_(2)fluid inclusions show 2 phases(liquid H_(2)O(LH_(2)O)+liquid CO_(2)(LCO_(2))at room temperature and homogenize to a critical state.CO_(2)is clearly more enriched in the fluid inclusions of stages 2 and 3 than in stage 1.Stage 1 is dominated by type A(H_(2)O-rich)inclusions with homogenization temperatures(Th)of 220–359℃and salinities of 1.1–3.1 wt%NaCl equivalent.Type B(CO_(2)-rich)inclusions gradually increase in stages 2 and 3.The Th range of type B inclusions in stage 2 is 241–397℃with salinities of 2.2–6.9 wt%NaCl equivalent;the Th range of type A inclusions is 217–373℃with salinities of 1.2–8.1 wt%NaCl equivalent.The Th range of type B inclusions in stage 3 is 215–361℃with salinities of 2.9–6.1 wt%NaCl equivalent;the range of type A inclusions is 158–351℃with a salinity of 0.7–5.5 wt%NaCl equivalent.Stage 4 is characterized by type A with Th of 151–250�

关 键 词：petrographic studies fluid inclusion gold deposit SRXRF Dongping 

分 类 号：P618.51[天文地球—矿床学] P575.5[天文地球—地质学]