矿床地质2025，Vol.44Issue(3)：559-580,22.DOI:10.16111/j.0258-7106.2025.03.003
新疆萨尔托海豆荚状铬铁矿后期蚀变作用
Hydrothermal alteration of Sartohay podiform chromite,Xinjiang
摘要
Abstract
The Sartohay chromite deposit in Xinjiang underwent intense late-stage hydrothermal alteration,resulting in the formation of four types of chromite:① Primary Cr-spinel;② Porous chromite;③ Porous ferrous chromite;④ Homogeneous ferrous chromite.The primary Cr-spinel shows a uniform texture,compositionally belonging to high-Al Cr-spinel.The porous chromite occurs as the irregular metasomatic rims that enclosed the primary Cr-spi-nel,having significantly increased Cr# and decreased Mg# values.The porous ferrous chromite appears as single grains,having higher Cr# values,lower Mg# values,and much higher Fe2+contents than the porous chromite.Ho-mogeneous ferrous chromite,which has the highest Fe3+contents,typically appears as overgrown rims.In the MORB chromite normalized spider diagram,the trace element patterns of the primary chromite spinel are general-ly"flat"with no significant anomalies,while the porous chromite shows obvious depletion of Ni and Sc and slight enrichment of Zn,Co,and Mn.The porous ferrous chromite and homogeneous ferrous chromite are strong-ly enriched in Zn,Co,Mn and Ni,and depleted in Ga and Sc.These textural and compositional features suggest that the primary Cr-spinel has undergone a two-stage fluid-mediated alteration process.In the first stage,the pri-mary Cr-spinel and olivine interact with reducing low-silica fluids to form porous chromite.Subsequently,porous chromite reacted with olivine to produce porous ferrous chromite in the presence of a high-silica-reducing fluid.During the second stage,the porous ferrous chromite interacted with ferrous oxidized fluids to form homoge-neous ferrous chromite under amphibolite facies condition.关键词
流体/微量元素/变质作用/铬铁矿/萨尔托海Key words
fluid/trace element/chromite/metamorphism/Sartohay分类
地质学引用本文复制引用
赵佳玉,申萍,冯浩轩,李昌昊,罗耀清,武阳,楚翔凯,索青宇,白应雄..新疆萨尔托海豆荚状铬铁矿后期蚀变作用[J].矿床地质,2025,44(3):559-580,22.基金项目
本文得到自治区重点研发项目(编号:2023B03006)、新疆维吾尔自治区人民政府国家305项目办公室和新疆维吾尔自治区"天池英才"引进计划联合资助 （编号:2023B03006）
