| 旷双磊,程大宇,李宝庆,周炜,陈乾龙.云南宣威市格学二叠纪锰矿成矿地质条件及地球化学特征[J].矿产勘查,2026,17(6):1009-1022 |
| 云南宣威市格学二叠纪锰矿成矿地质条件及地球化学特征 |
| Geological conditions and geochemical characteristics of the Permian manganese mineralization in Gexue, Xuanwei City, Yunnan Province |
| 投稿时间：2024-12-15 |
| DOI：10.20008/j.kckc.202606007 |
| 中文关键词: 成矿环境 地球化学 锰矿 二叠纪 云南格学 |
| 英文关键词: mineralization environment geochemistry manganese deposit Permian Gexue, Yunnan |
| 基金项目:本文受云南省有色地质局2024年度局投资综合研究项目“云南省宣威格学—来宾锰矿成矿规律研究及靶区优选”(2024--05)资助。 |
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| 中文摘要: |
| 格学锰矿属碳酸盐型锰矿，形成于静水环境，位于黔北―滇东二叠纪锰矿成矿带，处于横跨黔北遵义延伸至滇东格学地区。本文以云南宣威市格学锰矿为研究对象，分析其成矿地质条件，讨论锰矿物质来源、沉积环境及锰沉淀方式。通过对矿区野外调查，对锰矿体、顶板及底板进行矿物组成、主量、微量及稀土元素分析测试。岩矿测试结果表明，矿区存在氧化锰和碳酸锰两种矿石类型，氧化锰矿石中见硬锰矿、软锰矿，碳酸锰矿石中主要为菱锰矿和少量的黄铁矿。Mn/Fe、Al2O3/TiO2、Co/Ni、Th/U、La/Ce、Y/Ho、Al/(Al+Fe+ Mn)比值，Fe-Mn-Al、Fe-Mn-(Cu+Ni+Co)×10、SiO2-Al2O3、logU-logTh图解等，均集中显示研究区含锰岩系沉积过程中明显受到热水活动的影响，成矿物质很可能主要来自于热液体系的贡献。研究区含锰岩系的氧化还原敏感指标(Mn/Fe、Ceanom特征值、V/Cr、Ni/Co和 V/(V+Ni)比值)特征及其图解显示，尽管各种氧化还原指标之间的某些细节解释存在差异性，但总体上研究区锰矿化过程水体可能经历氧化-还原循环转化的过程。对比邻区贵州及国内外二叠系锰矿最新研究成果，综合地质、地球化学特征，认为研究区锰矿形成过程中受到了热液活动的明显影响，成矿物质主要来自于热液体系的贡献，锰矿化过程水体可能经历次氧化-还原循环转化的过程，研究成果对区内下一步找矿工作具有一定的指导意义。 |
| 英文摘要: |
| The Gexue manganese deposit is a carbonate-type manganese deposit formed in a stagnant water en-vironment, located within the Permian manganese metallogenic belt spanning from northern Guizhou to eastern Yun-nan, which extends from Zunyi in northern Guizhou to the Gexue area in eastern Yunnan. This study focuses on theGexue manganese deposit in Xuanwei City, Yunnan Province, analyzing its metallogenic geological conditions anddiscussing the sources of manganese minerals, sedimentary environment, and manganese precipitation mechanisms.Through field investigations of the mining area, mineral composition, major, trace, and rare earth element analyseswere conducted on the manganese ore bodies, roof, and floor of the Xuanwei Gexue manganese deposit. Petrologicaland mineralogical tests reveal two types of ores in the mining area: oxidized manganese ore and carbonate manga-nese ore. The oxidized manganese ore contains psilomelane and pyrolusite, while the carbonate manganese ore pri-marily consists of rhodochrosite with minor pyrite. Ratios such as Mn/Fe, Al2O3/TiO2, Co/Ni, Th/U, La/Ce, Y/Ho, and Al/(Al+Fe+Mn), as well as Fe-Mn-Al, Fe-Mn-(Cu+Ni+Co)×10, SiO2-Al2O3, and logU-logTh diagrams, collectivelyindicate that the manganese-bearing series in the study area was significantly influenced by hydrothermal activityduring sedimentation. The ore-forming materials were likely derived mainly from contributions of the hydrothermalsystem. Redox-sensitive indicators (e.g., Mn/Fe, Ce anomalies, V/Cr, Ni/Co, and V/(V+Ni) ratios) and their corre-sponding diagrams suggest that, although there are some interpretative differences in the details among various re-dox proxies, the water body during manganese mineralization in the study area likely underwent an oxidative-reductive cyclic transformation process. By comparing the latest research on Permian manganese deposits in neigh-boring Guizhou and other global counterparts, and integrating geological and geochemical characteristics, this studyconcludes that the formation of the manganese deposit in the study area was markedly influenced by hydrothermalactivity, with ore-forming materials predominantly sourced from the hydrothermal system. The manganese mineral-ization process likely involved a suboxic-aNOxic cyclic transformation of the water body, providing valuable guid-ance for further prospecting in the region. |
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