投稿时间：2024-10-13
修订日期：2025-06-30
网络发布日期：2025-08-26
中文摘要:内蒙古扎拉格阿木铜矿床位于大兴安岭中南段西坡的南端，是该地区新发现的一个晚中生代的中型铜矿床。铜矿体主要赋存在二叠纪花岗闪长岩与二叠系哲斯组砂板岩和火山碎屑岩的外接触带中，矿石类型可划分为粉砂岩型、花岗闪长岩型和角砾岩型矿石。金属矿物主要是黄铁矿、黄铜矿和少量的闪锌矿和方铅矿。文章通过精细的矿物学研究，发现该矿床的铜矿石中出现了一系列具有重要成因指示意义的Fe(Co)-As-S体系矿物，包括毒砂、斜方砷铁矿、铁硫砷钴矿等。在矿相学研究的基础上，结合电子探针分析进一步细分出3种类型毒砂（Apy-Ⅰa、Apy-Ⅰb、Apy-Ⅱ），2种类型斜方砷铁矿（Lo-Ⅰa、Lo-Ⅰb），1种铁硫砷钴矿（Gl）和3种类型的黄铁矿（Py-Ⅰa、Py-Ⅰb、Py-Ⅱ）。精细的矿物学研究表明，该矿区铜矿石中存在着显著的Co、Ni异常。研究表明：Apy-Ⅰa主要分布在粉砂岩矿石中具有较高的w(Co)（7.92%）、w(Ni)（3.14%）；Apy-Ⅰb主要分布在黑云花岗闪长岩矿石中，w(Co)（0.97%）、w(Ni)（1.46%）降低；Apy-Ⅱ主要分布在角砾岩型铜矿石中，基本不含Co、Ni。Lo-Ⅰa分布在粉砂岩型铜矿石中，Lo-Ⅰb分布在黑云花岗闪长岩矿石中，两类斜方砷铁矿都含有较高的Co、Ni含量，其中Lo-Ⅰa中的w(Co)（5.08%）大于w(Ni)（2.86%），Lo-Ⅰb中w(Ni)（4.99%）高于w(Co)（0.76%）。铁硫砷钴矿主要分布在粉砂岩型铜矿石中交代早期的斜方砷铁矿，具有高的w(Co)（18.65%）、w(Ni)（4.35%）。Py-Ⅰa分布在粉砂岩矿石中，具有较高的w(Co)（401.41×10-6）、w(Ni)（698.92×10-6）；Py-Ⅰb分布在花岗闪长岩矿石中，w(Co)（68.62×10-6）降低，w(Ni)（1465.47×10-6）升高；Py-Ⅱ分布在角砾岩型铜矿石中，几乎不含Co、Ni。根据矿物组合及穿插关系将该矿床的矿化阶段划分为2期，Ⅰ期主要为中高温的变质作用，发育粉砂岩和糜棱状黑云花岗闪长岩；Ⅱ期以热液交代、填充角砾岩型铜矿石为主，含Ag、Bi的中低温矿物。通过毒砂温度计计算得出第Ⅰ期粉砂岩和花岗闪长岩中毒砂平均温度分别为455.9℃、466.1℃，平均硫逸度logf(S2)分别为-7.89和-7.63；第Ⅱ期角砾岩型毒砂的平均温度380.3℃，平均硫逸度logf(S2)为-10.02。初步研究认为扎拉格阿木铜多金属矿床属中高温-变质-热液交代叠加型矿床，且在早期的中高温热液作用形成的矿石中呈现Co、Ni富集的特征，是一个潜在的富钴镍的矿床。
中文关键词:铁（钴）-硫-砷系矿物 电子探针 矿物温度计 扎拉格阿木
Abstract:The Zhalageamu copper deposit is located on the western slope of the southern segment of the Central-South Daxing'anling Range and is a newly discovered Mesozoic medium-sized copper deposit in the area. The copper orebodies are mainly hosted in the outer contact zone between the Permian granodiorite and the Permian Zhesi Formation sandy slate and volcanic clastic rocks. The ores could be classified into siltstone-type, granodiorite-type, and breccia-type ores. The main ore minerals are pyrite, chalcopyrite, and minor sphalerite and galena. Through detailed mineralogical research, a series of Fe(Co)-As-S system minerals with significant genetic implications have been identified in the copper ores of the deposit, including arsenopyrite, lollingite, and glaucodot. Based on mineralographical studies and combined with electron microprobe analysis, three types of arsenopyrite (Apy-Ⅰa、Apy-Ⅰb、Apy-Ⅱ), two types of lollingite (Lo-Ⅰa、Lo-Ⅰb), one type of glaucodot（Gl）and three types of pyrite (Py-Ⅰa、Py-Ⅰb、Py-Ⅱ), were subdivided. It is found that there are significant Co and Ni anomalies in the copper ores of the deposit. Apy-Ⅰa is mainly distributed in siltstone with higher Co (7.92%) and Ni (3.14%) content; Apy-Ⅰb is mainly distributed in biotite granodiorite with lower Co (0.97%) and Ni (1.46%) content; Apy-Ⅱ is mainly distributed in breccia-type copper ores, containing almost no Co, Ni. Lo-Ⅰa is distributed in siltstone-type copper ores, and Lo-Ⅰb is distributed in biotite granodiorite, both types of lollingite contain higher Co, Ni content, among which Lo-Ⅰa has a Co (5.08%) content greater than Ni (2.86%) content, and Lo-Ⅰb has a Ni (4.99%) content greater than Co (0.76%) content. Glaucodot is mainly distributed in siltstone-type copper ores, replacing early-stage lollingite, with high Co (18.65%) and Ni (4.35%) content. Py-Ⅰa is distributed in siltstone with higher Co (401.41×10-6) and Ni (698.92×10-6) content, Py-Ⅰb is distributed in granodiorite with reduced Co (68.62×10-6) content, and increased Ni (1465.47×10-6) content, Py-Ⅱ is distributed in breccia-type copper ores, containing almost no Co, Ni. Based on the mineral assemblage and crosscutting relationships, the mineralization of the deposit are divided into two stages. The stage Ⅰ is mainly characterized by medium to high-temperature metamorphism, with the development of ore minerals in siltstone and mylonitic biotite granodiorite; the stage Ⅱ is dominated by hydrothermal alteration and filling of breccia-type copper ores, containing Ag, Bi in medium to low-temperature minerals. The arsenopyrite thermometer calculation shows that the average temperature of arsenopyrite in stage Ⅰ siltstone and granodiorite is 455.9℃ and 466.1℃, respectively, and the average temperature of arsenopyrite in stage Ⅱ breccia-type ores is 380.3℃. Preliminary studies suggest that the Zhalageamu polymetallic copper deposit belongs to a medium to high-temperature metamorphic-hydrothermal alteration superimposed type deposit, and it shows Co, Ni enrichment in ores formed in stage Ⅰmedium to high-temperature hydrothermal action, making it a potential cobalt and nickel-rich deposit.
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基金项目:本文得到国家自然科学基金项目（编号：41672035）资助
引用文本：
吴伟民,刘文元,陈镜文.2025.内蒙古扎拉格阿木铜矿床中Fe(Co)-As-S系列矿物的矿物学特征及成因意义[J].矿床地质,44(4):756~772WU WeiMin,LIU WenYuan,CHEN JingWen.2025.Mineralogical characteristics and genetic significance of Fe(Co)-As-S series minerals in Zhalageamu copper deposit, Inner Mongolia[J].Mineral Deposits44(4):756~772
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