西北地质2025，Vol.58Issue(4)：56-68,13.DOI:10.12401/j.nwg.2025073
金川铜镍矿床多硫同位素和铁同位素特征及成因意义
Characteristics and Genetic Implications of Multiple Sulfur and Iron Isotopes in the Jinchuan Cu-Ni Deposit
摘要
Abstract
The Jinchuan Ni-Cu deposit is the largest magmatic Ni-Cu sulfide deposit in China.Previous studies shown that there is a high degree of contamination in the mineralization process of the Jinchuan deposit,but the source of the contaminating material and the mechanism that causes the sulfide melt segregation from the mag-ma are still controversial.In this paper,we use a combination of multiple S(δ34S+Δ33S)and Fe(δ56Fe)isotopes to trace the contaminated crustal materials during the mineralization process of the Jinchuan deposit,especially the influence of sulfur in Archean sedimentary rocks on the sulfur saturation of the Jinchuan deposit.The Δ33S value of sulfide minerals in the segment Ⅰ and Ⅱ of the Jinchuan deposit is from-0.07‰ to 0.22‰,which ex-ceeds the Δ33S value of mantle-derived magma and is completely different from the Δ33S value of pyrite(-0.04‰～-0.08‰)in the wall rock of the Jinchuan deposit,indicating that the contamination of the Jinchuan magma should occur at depth and have nothing to do with its direct wall rock.The δ56Fe value of pyrrhotite in the Jinchuan deposit is from-1.07‰ to-0.33‰.Calculations show that the δ56Fe value of Jinchuan parent mag-ma in equilibrium with the sulfide melt is-0.7‰,which is far lower than the normal mantle-derived basaltic magma range.In addition,pyrrhotite in sulfide ores with positive Δ33S values usually has very low δ56Fe values,and Δ33S-δ56Fe values have a significant negative correlation,indicating that the sulfide segregation in the Jinchuan parent magma may be due to the contamination of pyrite in Archean sedimentary rocks.关键词
硫化物熔离/同化混染作用/太古宙地壳硫/金川铜镍矿床Key words
sulfide segregation/contamination/archean crustal sulfur/Jinchuan Ni-Cu deposit分类
天文与地球科学引用本文复制引用
段俊,Teuku Amrul Mahdi,王宁,徐刚,房明举,付易遥,贾天河..金川铜镍矿床多硫同位素和铁同位素特征及成因意义[J].西北地质,2025,58(4):56-68,13.基金项目
国家自然科学基金项目(U2444203、41802081、42473027),陕西省自然科学基础研究计划项目(2023-JC-YB-224),长安大学创新创业训练计划项目(S202410710300)联合资助. （U2444203、41802081、42473027）
