成都理工大学学报（自然科学版）2025，Vol.52Issue(3)：456-479,24.DOI:10.12474/cdlgzrkx.2024112601
扬子西缘摩挲营新元古代高分异花岗岩年龄、成因和锡钨成矿潜力
Geochronology,petrogenesis,and tin-tungsten metallogenic potential of the Neoproterozoic highly fractionated granites in the Mosuoying area,western margin of the Yangtze Block
摘要
Abstract
The Mosuoying granite pluton is situated in the Kangdian Axis in the western Yangtze Block,where tin-tungsten mineralization has developed in the contact zone between granite and carbonate rocks.This study aims to investigate the petrogenesis and ore potential of the pluton through geochronology,whole-rock geochemistry,and zircon Hf isotopic analysis.The LA-ICP-MS zircon U-Pb ages of the porphyritic biotite granite and fine-grained biotite granite are 842±6 Ma and 841±7 Ma,respectively,with zircon εHf(t)values ranging from-10.0 to-2.5 and-16.9 to-3.8 and two-stage model ages(TDM2)ranging from 2.35 to 1.89 Ga and 2.29 to 1.96 Ga.These indicate that the magma were derived from re-melting of ancient crust.The Mosuoying granites are peraluminous and high-K calc-alkaline,with high light rare earth element/heavy rare earth element ratios and pronounced negative Eu anomalies.They are enriched in Sn,Be,W,Rb,K,and Th and depleted in Ba,Nb,Sr,P,and Ti.Low whole-rock K/Rb,Nb/Ta,and Zr/Hf ratios,coupled with high Rb/Sr ratios,suggest intense fractional crystallization.Based on these geochemical characteristics,the Mosuoying granites are classified as highly fractionated S-type granites.The calculated relative oxygen fugacity values and zircon Ce4+/Ce3+ratios range from-5.84 to-0.93(average of-3.72)and 0.23 to 14.02(average of 2.55),respectively,indicating low oxygen fugacity.The occurrence of greisenization,tourmalinization,and fluoritization in the Mosuoying granites indicates hydrothermal fluid activity.During ocean-continent subduction,upwelling of the asthenosphere triggered re-melting of ancient crust and the formation of volatile-rich,highly-fractionated reduced granites,providing conditions favorable for tin-tungsten mineralization.The Neoproterozoic highly fractionated granites in the Mianning-Huili area are thus considered to be a key target for further tin-tungsten exploration.关键词
摩挲营岩体/新元古代/锆石U-Pb年代学/Hf同位素/高分异S型花岗岩Key words
Mosuoying pluton/Neoproterozoic/zircon U-Pb dating/Hf isotope/highly fractionated S-type granite分类
天文与地球科学引用本文复制引用
邓藤丽,彭磊,彭义伟,程文斌,郎兴海,宋明伟,梁芳硕,蔡姬敏,许文丽,李家辉..扬子西缘摩挲营新元古代高分异花岗岩年龄、成因和锡钨成矿潜力[J].成都理工大学学报（自然科学版）,2025,52(3):456-479,24.基金项目
成都理工大学三星堆多学科综合研究项目(11400-000525-18) （11400-000525-18）
国家自然科学基金项目(41702081). （41702081）
