矿床地质2026，Vol.45Issue(2)：457-474,18.DOI:10.16111/j.0258-7106.2026.02.014
北淮阳成矿带东段新元古代花岗岩体成因及其找矿指示
Genesis and implication for mineral exploration of Neoproterozoic granite plutons in eastern section of Beihuaiyang metallogenic belt
摘要
Abstract
Neoproterozoic felsic intrusions are widely exposed in the eastern segment of the Beihuaiyang Metalorgenic Belt,dominated by syenogranitic gneiss with subordinate syn-to post-tectonic syenogranite intrusions.These plu-tons host spatially and temporally associated with Pb-Zn mineralization,rendering their petrogenesis pivotal for constraining the tectonic evolution and metallogenic framework of the belt.This study focuses on the Neoprotero-zoic granitoids from the Maotanchang area,integrating zircon U-Pb geochronology,whole-rock major-and trace-element geochemistry.LA-ICP-MS zircon U-Pb dating yields concordant weighted mean 206Pb/238U ages of(803.2±1.3)Ma for the syenogranitic gneiss and(803.9±1.4)Ma for the syenogranite,indicating coeval emplace-ment during the Mid-Neoproterozoic(～804 Ma).Geochemically,both rock types are silica-rich(w(SiO2)=65.85％～75.74％),and markedly Mg-poor(w(MgO)=0.05％～0.93％;Mg#=21～47).Chondrite-normalized REE patterns display strong light-REE enrichment((La/Yb)N=33.1～50.57),steep heavy-REE depletion,and pro-nounced negative Eu anomalies(δEu=0.19～0.33).Trace element spider diagrams exhibit marked enrichment in Rb,Th,U,K,Pb,Zr,Hf,Ce,Nd,and La,coupled with systematic depletions in Sr,Ba,Ti,Nb,Ta,and P.Petroge-netic discrimination classifies both units as A-type granites.Their geochemical signatures point to partial melting of potassium-rich,felsic lower-to-middle crust.This melting event occurred during regional lithospheric exten-sion following the culmination of the Jinningian Tongbai-Dabie orogeny.Given the tight spatiotemporal associa-tion between these A-type intrusions and Pb-Zn mineralization,this work provides new guidance for future Pb-Zn deposit exploration targeting in the eastern Beihuaiyang Belt.关键词
地球化学/U-Pb年龄/A型花岗岩/北淮阳Key words
geochemistry/U-Pb dating/A-type granites/Beihuaiyang分类
天文与地球科学引用本文复制引用
武彬,张雪辉,王冲,丰效坤,韦星,张翔,龚赞,方舒彬,孙建东..北淮阳成矿带东段新元古代花岗岩体成因及其找矿指示[J].矿床地质,2026,45(2):457-474,18.基金项目
本文得到深地国家科技重大专项项目(编号:2025ZD1007401)、新一轮找矿突破战略行动科技支撑项目(编号:ZKKJ202525)、中国地质调查局项目(编号:DD20240202702、DD202402027)和国家自然科学基金(批准号:42402095)联合资助 （编号:2025ZD1007401）
