岩石矿物学杂志2025，Vol.44Issue(3)：535-555,21.DOI:10.20086/j.cnki.yskw.2025.4101
鄂东南石头咀矽卡岩型Cu-Fe矿床石榴子石原位成分、U-Pb测年及其地质意义
In situ composition and U-Pb dating of garnets from the Shitouzui Cu-Fe skarn deposit in southeastern Hubei Province and its geological implications
摘要
Abstract
The Shitouzui Cu-Fe deposit is one of the typical skarn deposits in the southeastern Hubei Province.Currently,its mineralization age and the evolution process of ore-forming fluids are not clear yet.Based on the field research and petrographic observation,three generations of garnets were identified in this deposit,and in situ EM-PA,LA-ICP-MS trace element and U-Pb dating of garnets were conducted for a systematic study.The results indi-cate that Grt1(Adr61～68Grs28～36)has small compositional variation,and formed by diffusion metasomatism;Grt2(Adr63～89Grs7～33)with oscillatory zoning exhibits significant compositional variation and formed by infiltration meta-somatism;the composition of Grt3(Adr82～89Grs5～11)is uniform and it resulted from crystallization of residual fluid.Y/Ho values(19.24～32.13,averaging at 26.46)suggest that the garnets in the Shitouzui deposit have the same magmatic fluid source.Relatively LREE-enriched and HREE-depleted patterns reflect that all these garnets precipitated in weakly acidic fluid condition.The characteristics of δEu,Sn and REE concentration indicate that the ore-forming fluid changed from relative reduced to oxidized condition,the intensity of water/rock reaction showed an increase to decrease feature,respectively,during the formation from Grt1,Grt2 to Grt3.The LA-ICP-MS U-Pb dating result of Grt2,138±1 Ma,accurately constrains the Cu-Fe mineralization age of the Shitouzui de-posit and further confirms the close genetic relationship between the mineralization and the Tonglüshan quartz dio-rite.The mineralization of the Shitouzui Cu-Fe deposit is a response to the early Yanshanian magmatic activity in southeastern Hubei Province.关键词
鄂东南/石头咀/石榴子石/成矿时代/流体演化Key words
southeastern Hubei Province/Shitouzui/garnet/mineralization age/ore-forming fluid evolution分类
地质学引用本文复制引用
匡华,张铭,赵岩岩,严子清,杨黎..鄂东南石头咀矽卡岩型Cu-Fe矿床石榴子石原位成分、U-Pb测年及其地质意义[J].岩石矿物学杂志,2025,44(3):535-555,21.基金项目
湖北省地勘基金项目(2021026368) Geological Exploration Fund Project of Hubei Province(2021026368) （2021026368）
