辽宁排山楼金矿床成矿物质来源和矿床成因:来自T4矿体C-O-S-Pb同位素地球化学的约束  

Ore-forming material sources and genesis of the Paishanlou gold deposit in the Liaoning Province,China:Constraints from the C-O-S-Pb isotope geochemistry of the T4 orebody

作　　者：刘春发 刘彦兵 刘必政[3] 徐立为 LIU Chunfa;LIU Yanbing;LIU Bizheng;XU Liwei(China National Gold Group Hong Kong Co.,Ltd.,Beijing 100011,China;School of Earth Sciences and Resources,China University of Geosciences(Beijing),Beijing 100083,China;China Gold Group Resources Co.,Ltd.,Beijing 101300,China;China Gold Group Geology Co.,Ltd.,Beijing 101300,China)

机构地区：[1]中国黄金集团香港有限公司,北京100011 [2]中国地质大学(北京)地球科学与资源学院,北京100083 [3]中国黄金集团资源有限公司,北京101300 [4]中国黄金集团地质有限公司,北京101300

出　　处：《地质科技通报》2025年第2期146-160,共15页Bulletin of Geological Science and Technology

基　　金：中国黄金集团有限公司地质科研项目(WKY201601)。

摘　　要：排山楼金矿床是华北克拉通北缘一处大型金矿床,矿床赋存于太古宇建平群中,受EW向和NE向2组韧性剪切带控制,与燕山期花岗岩类关系密切,长久以来关于其矿床成因类型存在较大争议。本研究以近年新揭露的T4矿体为研究对象,系统开展矿床地质和C、O、S、Pb同位素研究,厘定成矿流体和物质来源,探讨其矿床成因。结果表明:矿石热液碳酸盐矿物δ^(13)C_(V-PDB)值为-7.0‰~-2.1‰,δ^(18)O_(V-SMOW)值为12.2‰~16.7‰。相较于高于庄组白云质大理岩,热液碳酸盐矿物C同位素组成基本一致,但O同位素组成明显亏损,暗示成矿流体中的C来源于高于庄组白云质大理岩的溶解。矿石黄铁矿δ^(34)S_(V-CDT)值介于0.5‰~7.5‰之间,其双峰值(2.9‰和6.7‰)与建平群变质岩和燕山期花岗岩类δ^(34)S_(V-CDT)值一致,表明S主要来源于建平群变质岩和燕山期岩浆硫的混合。矿石黄铁矿^(206)Pb/^(204)Pb、^(207)Pb/^(204)Pb、^(208)Pb/^(204)Pb值分别为16.585~18.432,15.299~15.698,37.159~38.982。在Pb演化图解中主要投点于地幔和下地壳区域,表明排山楼金矿床铅以壳幔混合为主,金属来源于建平群变质岩和燕山期花岗岩类。结合晚中生代区域构造-岩浆演化背景,认为在晚白垩世华北克拉通北缘区域伸展、岩石圈快速减薄的背景下,排山楼地区韧性剪切作用导致前寒武纪岩石发生动力变质作用形成含矿变质热液,运移过程中有岩浆热液、大气降水及围岩成矿物质参与,最终在构造有利部位发生水岩反应导致成矿物质迅速沉淀,排山楼金矿床成因类型为造山型金矿。[Objective]The Paishanlou gold deposit is a large gold deposit on the northern margin of the North China Craton,containing more than 60 tons of gold resources.It is mainly hosted in Archean metamorphic rocks of the Jianping Group,structurally controlled by EW and NE ductile shear zones,and closely related to the Yanshanian granites.For many years,the genetic type of the Paishanlou gold deposit is still controversial.[Methods]In this study,we present new field geology and C-O-S-Pb isotope data for the T4 orebody in the Paishanlou deposit,in order to identify the ore-forming material sources and its genesis.[Results]Theδ^(13)C_(V-PDB)and theδ^(18)O_(V-SMOW)values of hydrothermal carbonate minerals from ores range from−7.0‰to−2.1‰and 12.2‰to 16.7‰respectively.Compared with the Gaoyuzhuang Formation dolomitic marble,theδ^(18)O_(V-SMOW)values are lower while theδ^(13)C_(V-PDB)values are almost identical,indicating that the C isotope in the ore-forming fluid was derived from the dissolution of dolomitic marble in the Gaoyuzhuang Formation.Theδ^(34)S values of pyrites from ores vary from 0.5‰to 7.5‰with two peak values(2.9‰and 6.7‰),which correspond toδ^(34)S values of the metamorphic rocks of Jianping Group and the Yanshanian granitoids,indicating the sulfurs were mainly derived from a mixed source of the metamorphic rocks of Jianping Group and the Yanshanian magmatic sulfur.The Pb isotopic compositions of the pyrites from ores vary from 16.585 to^(18).432,15.299 to 15.698 and 37.159 to 38.982 for^(206)Pb/^(204)Pb,^(207)Pb/^(204)Pb and^(208)Pb/^(204)Pb ratios respectively,which plot between the mantle and lower crust fields in the^(207)Pb/^(204)Pb versus^(206)Pb/^(204)Pb discrimination diagrams,indicating a mixed source of crust and mantle.Thus,we suggest the ore-forming metals were derived from a mixed source of metamorphic rock of Jianping Group and the Yanshanian granitoids.[Conclusion]Combined with the regional tectono-magmatic evolution history during the Mesozoic,we propose that the NE d

关 键 词：排山楼金矿 C-O-S-Pb同位素 成矿物质来源 矿床成因 华北克拉通北缘 地球化学 

分 类 号：P618.51[天文地球—矿床学]