地质科技通报2025，Vol.44Issue(2)：146-160,15.DOI:10.19509/j.cnki.dzkq.tb20240306
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
摘要
Abstract
[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]The δ13CV-PDB and the δ18OV-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,the δ18OV-SMOW values are lower while the δ13CV-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.The δ34S values of pyrites from ores vary from 0.5‰ to 7.5‰ with two peak values(2.9‰ and 6.7‰),which correspond to δ34S 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 206Pb/204Pb,207Pb/204Pb and 208Pb/204Pb ratios respectively,which plot between the mantle and lower crust fields in the 207Pb/204 Pb versus 206Pb/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 ductile shearing in the Paishanlou district resulted in dynamic metamorphism of Precambrian country rocks to form ore-bearing metamorphic fluid under the background of the regional extensional tectonism and lithosphere thinning during the late Cretaceous.During the migration of the ore-forming fluid along the ductile shear zone,the meteoric water,magmatic hydrothermal fluid and ore-forming materials from the country rocks were involved in it,resulting in the characteristics of crust-mantle mixing.Finally,in the favorable environment such as tectonic intersection or dolomitic marble interface,the ore-forming fluid reacted with the country rock,leading to the rapid precipitation of ore-forming materials.The Paishanlou gold deposit belongs to orogenic gold deposit.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Key words
Paishanlou gold deposit/C-O-S-Pb isotope/ore-forming material source/orogenic gold deposit/northeastern margin of North China Craton/geochemistry分类
地质学引用本文复制引用
刘春发,刘彦兵,刘必政,徐立为..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[J].地质科技通报,2025,44(2):146-160,15.基金项目
中国黄金集团有限公司地质科研项目(WKY201601) （WKY201601）
