投稿时间：2019-07-01
修订日期：2019-12-20
网络发布日期：2020-05-14
中文摘要:表生环境中存在2种机制可以形成碳酸锰矿物：①从缺氧海水中直接沉淀；②先在氧化海水中形成锰氧化物，随后在埋藏过程中通过成岩作用转化为碳酸锰。目前，主流观点认为只有通过第二种机制才可以形成碳酸锰矿床，并在此基础上提出了极端地质事件（如大氧化事件、雪球事件）、闭塞盆地、最小含氧带扩张等成矿模型，近年来同时强调微生物活动、底层水氧化持续时间在成矿中发挥关键作用。沉积碳酸锰成矿不仅与古大气组分、古海洋状态、初级生产力、海底热液活动等多个圈层的耦合作用关系密切，同时也会影响多种生命元素（C、N、S、P等）和氧化还原敏感元素（U、V、Mo、Tl等）的表生循环，因此富碳酸锰的沉积岩是探讨古环境及海洋元素循环的重要载体。目前在沉积碳酸锰成矿理论方面有待深入探讨的问题包括：①碳酸锰直接沉淀成矿的可能性与有效性；②锰质来源与铁锰分离机制的识别；③主要控矿因素的识别及其时空演化规律；④矿石矿物组合及矿床地球化学对成岩精细过程的制约。
Abstract:There are two mechanisms for the formation of manganese carbonate minerals in supergene environment:① minerals precipitated directly from anoxic seawater; ② manganese carbonates formed as a result of manganese oxides reduction by organic matter during burial diagenetic reaction. At present, the prevailing consensus is that only through the second mechanism can manganese carbonate deposits be formed. On such a basis, some metallogenic models, such as extreme geological events (Great Oxidation Event, Snowball Event), euxinic basin and oxygen minimum zone expansion, have been put forward. In recent years, the key roles of microbial activities and oxidation duration of bottom water in mineralization have been emphasized. Sedimentary manganese carbonate mineralization is closely related to the coupling of many spheres including paleo-atmospheric composition, paleo-oceanic state, primary productivity and submarine hydrothermal activities. Meanwhile, it can also affect the supergene cycle of various life elements (C, N, S, P, etc.) and redox sensitive elements (U, V, Mo, Tl, etc.). Therefore, sedimentary rocks rich in manganese carbonate are important tools for reconstructing paleoenvironment and oceanic element cycles. So far, the problems deserving further discussion in the theory of sedimentary manganese carbonate mineralization include:① the possibility and efficiency of direct precipitation for manganese carbonate mineralization; ② the discrimination of manganese source and separation mechanism of iron and manganese; ③ the identification of major ore-controlling factors and their temporal-spatial evolution characteristics; ④ The constraints of ore mineral assemblages and geochemistry on the details of diagenetic processes.
keywords:geology progress and problems paleoenvironment metallogenic mechanism sedimentary manganese carbonate
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基金项目:本文得到国家自然科学基金项目（编号：U1703242）、国家重点研发计划深地专项（编号：2018YFC0604001-2）和矿产地质调查项目（编号：DD20190166-19）的联合资助
引用文本：
董志国,张连昌,王长乐,张帮禄,彭自栋,朱明田,冯京,谢月桥.2020.沉积碳酸锰矿床研究进展及有待深入探讨的若干问题[J].矿床地质,39(2):237~255DONG ZhiGuo,ZHANG LianChang,WANG ChangLe,ZHANG BangLu,PENG ZiDong,ZHU MingTian,FENG Jing,XIE YueQiao.2020.Progress and problems in understanding sedimentary manganese carbonate metallogenesis[J].Mineral Deposits39(2):237~255
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