北京科技大学谢玉玲研究小组近日取得一项新成果。经过不懈努力，他们报道了与中非带喀麦隆与金有关的金属来源。相关论文发表在2024年2月21日出版的《地球化学学报》杂志上。

研究对主岩进行XRF、ICP-MS全岩地球化学分析和BSE/EDS矿物分析，以调查本省与金相关的金属来源。岩相学上，黄铜矿—黄铁矿和磁铁矿—钛铁矿分别是花岗岩的主要硫化物和氧化物。低品位变质岩富含硫化物，包括毒砂、黄铜矿、黄铁矿和闪锌矿，氧化物包括磁铁矿、钛铁矿、赤铁矿和金红石。

与低品味变质岩相比，高品位变质岩和花岗岩中Cu、Ni、Co、Sb、Sc和Zn含量明显减少。Bi、Cd、Co、Cu、Ni、Sb、V、W、Zn含量随温度升高呈递减趋势，由低品位岩石向高品位岩石和花岗岩转变。高品位岩石和花岗岩中的贫化元素组几乎与金矿中富集的元素相同。研究结果强调，与喀麦隆东部省金矿化有关的金属(Bi、Cd、Co、Cu、Ni、Sb和Zn)可能来源于部分熔融前的进变质过程中富金属的低品位变质岩。

据悉，花岗岩和变质岩的组合为研究与金矿有关的金属来源提供了良好的地质环境。在喀麦隆东部省，出现在变质岩和花岗岩中的金属相关金(品位约为4.6g/t)的来源仍不明确。

附：英文原文

Title: Source of metals related to gold occurrences in Cameroon, Central African Belt

Author: Ndonfack, Kevin Igor Azeuda, Zhang, Jinlin, Xie, Yuling, Samiratou Yaya, N., Basua, Emmanuel Archelaus Afanga

Issue&Volume: 2024-02-21

Abstract: Suites of granitic and metamorphic rocks form a perfect geological environment in which to investigate the source of metals related to gold deposits. In the East Province of Cameroon, the source of metals-related gold (grade ~ 4.6g/t) that occurs within metamorphic and granitic rocks remains ambiguous. The host rocks were subjected to XRF and ICP-MS whole-rock geochemistry and BSE/EDS mineral analyses to investigate the source(s) of metals related to gold in the Province. Petrographically, chalcopyrite-pyrite and magnetite-ilmenite are the main sulfides and oxides of granites, respectively. The low-grade metamorphic rocks are sulfide-rich consisting of arsenopyrite, chalcopyrite, pyrite, and sphalerite, and oxides include magnetite, ilmenite, hematite, and rutile. Cu, Ni, Co, Sb, Sc, and Zn concentrations depleted in high-grade metamorphic rocks and granites compared to low-grade metamorphic rocks. As well, Bi, Cd, Co, Cu, Ni, Sb, V, W, and Zn concentrations decrease with increasing temperatures from low-grade rocks to high-grade rocks and granites. The suite of depleted elements in high-grade rocks and granites is almost identical to those enriched in gold occurrences. We conclude that metals (Bi, Cd, Co, Cu, Ni, Sb, and Zn) related to gold mineralization in the East Province of Cameroon likely originated from metal-rich low-grade metamorphic rocks during prograde metamorphic processes prior to partial melting.

DOI: 10.1007/s11631-023-00669-9

Source: https://link.springer.com/article/10.1007/s11631-023-00669-9