投稿时间：2024-08-29
修订日期：2024-11-05
网络发布日期：2025-03-10
中文摘要:富铁矿是中国大宗紧缺的战略性矿产，鄂东南矿集区“大冶式”铁矿是中国富铁矿的主要类型之一，前人对其成矿规律和找矿勘查技术做过大量的研究，取得了重要进展，提出“大冶式”铁矿为广义矽卡岩型矿床，但成岩成矿事件格架、矽卡岩铜矿与铁矿成矿差异、矿床组合模型和隐伏矿找矿有效技术方面的研究相对薄弱。笔者全面整理分析20余年的地质和物探等资料，确定大冶式铁矿存在两期成岩成矿事件：早期矽卡岩铜铁矿床和成铜岩体，晚期矽卡岩铁矿和成铁岩体。早期成铜岩体和晚期成铁岩体在岩石组合、源区性质、地幔贡献比例方面存在明显不同，矽卡岩铜铁矿床含矿岩浆的地幔物质所占比例明显高于矽卡岩铁矿床。大型矽卡岩铁矿所需的硫主要来源于膏盐层，膏盐矿物中的硫在岩浆-热液过渡阶段参与成矿作用，膏盐层参与矽卡岩铁矿床成矿作用的比例大于矽卡岩铜铁矿床。在此基础上，文章建立了“大冶式”铁矿的矿床组合模型，提出幔源组分和膏盐层参与成矿比例的不同，是造成矽卡岩铜铁矿与铁矿成矿差异的主要原因。创建两套隐伏“大冶式”铁矿的有效找矿技术组合，分别为1∶5万~1∶1万高精度航磁+1∶2 000地面高磁+井中磁测+可控音频大地电磁、可控音频大地电磁+广域电磁法+微动探测+多元素原生晕，建立了找矿模型，拓宽了鄂东南地区“大冶式”铁矿的找矿方向。
Abstract:High-grade iron deposits are a strategic mineral resource that is in short supply in China. The “Daye-type” iron deposits in the Edongnan district supply most of the high-grade iron resources in China. Numerous studies have focused on the metallogeny and mineral exploration methods, and the “Daye-type” iron deposits have been interpreted as the skarn deposit, however, the framework of causative magma and mineralization events, differences in Cu and Fe mineralization, integrated ore deposit model and effective exploration techniques for concealed orebodies remain unclear. This contribution comprehensively has collected and analyzed the geological and geophysical data from the past 20 years, and two distinct episodes of causative magma evolution and mineralization events for the “Daye-type” iron deposit have been recognized, i. e. early Cu-Fe skarn deposits and Cu-bearing magmatic rocks during Late Jurassic to Early Cretaceous, and late Fe skarn deposits and Fe-bearing magmatic rocks during Early Cretaceous. The causative magma composition, source properties, and percentage of mantle contribution between these two mineralization events are significantly different, and the proportion of mantle material in the causative Cu-bearing magmatic rocks is significantly higher than that related to Fe deposits. The sulfur required for large Fe deposits is mainly derived from the evaporite minerals in the wall rocks. The sulfur sourced from evaporate rocks participates in Fe mineralization processes during the magmatic-hydrothermal stage and the involved proportion of them in the Fe deposits is greater than that of Cu-Fe deposits. The integrated ore deposit model has been established, and differences in the proportion of mantle-derived components and the percentage of evaporite rocks involved in mineralization processes are the two reasons for the differentiation mineralization between skarn Cu-Fe deposits and Fe deposits. Two sets of effective exploration techniques for concealed “Daye-type” iron deposits were established, including 1∶50000 to 1∶10000 High-Precision Airborne Magnetic+1∶2000 Surface Magnetic+Borehole Magnetic+Controlled Source Avdio Magneto Telluric, and Controlled Source Audio Magneto Telluric+Wide-Field Electromagnetic Method+Microtremor Technique+Multielement Geochemical Primary Halos. The research also proposed the mineral exploration model which expands the direction for the “Daye-type” iron deposits in the Edongnan district and elsewhere.
keywords:“Daye-type” iron deposit paragenesis and separation mechanism of Cu and Fe evaporate rocks-associated mineralization ore deposit model mineral exploration technique
文章编号：
中图分类号：
文献标志码：
基金项目:本文得到国家自然科学基金项目(编号：41925011、91962214)，国家重点研发计划项目之课题(编号：2022YFC2903601) 和专题（编号：2022YFC2903705-02）共同资助
引用文本：
谢桂青,朱乔乔,高宝龙,吴昌雄,吴晓林,李伟,毛景文,梅燕雄.2025.大冶式铁矿的矿床模型探讨[J].矿床地质,44(1):67~84XIE GuiQing,ZHU QiaoQiao,GAO BaoLong,WU ChangXiong,WU XiaoLin,LI Wei,MAO JingWen,MEI YanXiong.2025.Discussion on ore model of Daye-type iron deposits[J].Mineral Deposits44(1):67~84
图/表
