近日，昆明理工大学教授李波及其课题组报道了云南西北yangla铜矽卡岩矿床黄铁矿和辉锑矿的微量元素组成及其锑矿化的成因。2024年3月18日，国际知名学术期刊《地球化学学报》发表了这一成果。

研究人员称，矿化可分为三种类型：铜-铅-锌(矽卡岩)黄铁矿、方铅矿、闪锌矿；铜(斑岩)黄铜矿、黄铁矿；锑(热液)辉锑矿、黄铁矿。锑矿中的矿物组合为辉锑矿+黄铁矿+方解石+石英±少量白钨矿。锑矿中的小白钨矿。本研究对羊拉锑矿中黄铁矿和辉锑矿微量元素组成进行了定量测定。电子探针微量分析(EPMA)表明，与黄铁矿中硫和铁的化学计量浓度相比，钴、镍、锑、砷和钼富集，硫和铁含量不足。

与锑相关的黄铁矿可能属于沉积改造成因，并可能受到热液的改造，因此与羊拉铜矽卡岩和斑岩型铜相关的黄铁矿相比，在晶体形态、结构和化学成分上存在一定的差异。辉锑矿的EPMA和电感耦合等离子体质谱分析表明，砷、铅、锡、铅、铜和锌富集于辉锑矿中，与锑和硫的化学计量浓度相比，锑含量明显较高，硫含量略低。研究还对辉锑矿微量元素进行统计分析，现象显示了元素对Cu-Pb、As-Sb和Sn-Pb的相关性，耦合置换方程Sb³⁺↔Cu⁺+Pb²⁺, Sb³⁺↔As³⁺和Sn²⁺↔Pb²⁺可能是控制辉锑矿中铜、铅、砷和锡结合的主要因素。此外，本研究初步表明羊拉锑矿化可能属于碳酸盐置换热液成因。

据介绍，羊拉矽卡岩矿床位于中国西南部金沙江缝合带中部，总储量为1.5 吨，含铜量1.03%。羊拉深部新发现的锑矿体受地层、构造和岩性的严格控制，在大理岩破碎带内呈透镜状和脉状分布，该现象为研究羊拉多期成矿和矿床成因提供了一个窗口。

附：英文原文

Title: Trace element compositions of pyrite and stibnite: implications for the genesis of antimony mineralization in the Yangla Cu skarn deposit, Northwestern Yunnan, China

Author: Pan, Ping, Wang, Xinfu, Li, Bo, Tang, Guo, Xiang, Zuopeng

Issue&Volume: 2024-03-18

Abstract: The Yangla Cu skarn deposit is located in the central part of the Jinshajiang Suture Zone, southwest China, with a total reserve of 150 Mt Cu @ 1.03%. The newly discovered antimony orebodies at the depth of Yangla are strictly controlled by the stratum, structure, and lithology, which are lenticular and vein-like within the marble fracture zone, which can provide a window into multistage mineralization and ore genesis at Yangla. Mineralization can be divided into three types, Cu–Pb–Zn (skarn) pyrite, galena, and sphalerite, Cu (porphyry) chalcopyrite and pyrite, and Sb (hydrothermal) stibnite and pyrite. The mineral assemblages were stibnite+pyrite+calcite+quartz±minor scheelite in antimony ores. This study presents quantitative measurements of the trace element compositions of pyrite and stibnite from the Yangla antimony ores. Analysis of pyrite with electron probe microanalysis (EPMA) showed enrichment in Co, Ni, Sb, As, and Mo, and deficit in its S and Fe contents when compared to the stoichiometric concentrations of S and Fe in pyrite. The Sb-related pyrite may belong to sedimentary-reworked genesis and may be modified by hydrothermal fluids, thereby presenting a certain difference (i.e., crystal morphology, texture, and chemical composition) compared to the skarn and porphyry Cu-related pyrite in the Yangla Cu skarn deposit. Analysis of stibnite with EPMA and inductively coupled plasma-mass spectrometry showed enrichment in As, Pb, Sn, Pb, Cu, and Zn, and presented much higher Sb contents and slightly lower S contents when compared to the stoichiometric concentrations of Sb and S in stibnite. Statistical analysis of the stibnite trace elements showed correlations for the elemental pairs Cu–Pb, As–Sb, and Sn–Pb, and the coupled substitution equations Sb³⁺↔Cu⁺+Pb²⁺, Sb³⁺↔As³⁺and Sn²⁺↔Pb²⁺ may be the major factors governed the incorporating Cu, Pb, As and Sn within the stibnite. Moreover, this study preliminary shows that the antimony mineralization may belong to a carbonate replacement hydrothermal genesis at Yangla.

DOI: 10.1007/s11631-024-00672-8

Source: https://link.springer.com/article/10.1007/s11631-024-00672-8