岩石矿物学杂志2026，Vol.45Issue(3)：447-467,21.DOI:10.20086/j.cnki.yskw.2026.5133
江苏高淳铜多金属矿早白垩世侵入岩成因
Genesis of the Early Cretaceous intrusive rocks in the Gaochun copper polymetallic deposit,Jiangsu Province:Evidence from zircon U-Pb geochronology and petrographic geochemistry
摘要
Abstract
The Gaochun Cu polymetallic deposit,located in the northern part of the Xuancheng ore concentration district within the Middle-Lower Yangtze River Metallogenic Belt,is a newly discovered mineralization area.This study focuses on diorite porphyry and quartz diorite porphyry exposed by drilling in the Gaochun mining area.Through zircon LA-ICP-MS U-Pb dating,whole-rock major and trace element analysis,zircon in-situ Hf isotopes,and whole-rock Sr-Nd isotope measurements,the formation age,magma source,and petrogenesis of the intrusive rocks are systematically investigated.The results show that the zircon U-Pb ages of diorite porphyry and quartz diorite porphyry are 134.1±2.0 Ma and 133.9±2.2 Ma,respectively,indicating they were products of Early Cretaceous magmatic activity.Geochemically,the rocks are characterized by high-K calc-alkaline and metaluminous affinity,enrichment in large ion lithophile elements(e.g.,Rb,Ba,Th),depletion in high field strength elements(e.g.,Nb,Ta,and Ti),significant fractionation of light and heavy rare earth elements,and weak Eu anomalies.Sr-Nd-Hf isotopic compositions suggest that the magmas were derived from mixing of an enriched mantle source and ancient crustal materials(Archean-Paleoproterozoic basement),accompanied by varying degrees of fractional crys-tallization and assimilation.Comparisons with intrusive rocks from the adjacent Chating ore district and the Tongling ore cluster indicate that the Gaochun intrusions are genetically linked to the first stage of crust-mantle interaction in the Middle-Lower Yangtze River Metallogenic Belt,formed in an intracontinental extensional setting following the subduction of the Paleo-Pacific Plate,involving magmatic underplating and mixing.This study provides new petro-geochemical evidence for understanding the deep magmatic-mineralization mechanisms in the Xuancheng ore cluster.关键词
高淳铜多金属矿/中酸性侵入岩/锆石U-Pb定年/岩石成因/长江中下游成矿带Key words
Gaochun Cu polymetallic deposit/intermediate-felsic intrusive rocks/zircon U-Pb dating/petrogenesis/Middle-Lower Yangtze River metallogenic belt分类
天文与地球科学引用本文复制引用
周欣,胡浩,朱碧,赵海香..江苏高淳铜多金属矿早白垩世侵入岩成因[J].岩石矿物学杂志,2026,45(3):447-467,21.基金项目
江苏省自然资源专项资金项目(苏财资环[2023]30号,[2024]33号) Jiangsu Provincial Special Fund for Natural Resources(Sucai Zihuan[2023]No.30,[2024]No.33) （苏财资环[2023]30号,[2024]33号）
