贵州石阡中坝钴锰矿床成因及其地质意义

Genesis and Geological Significance of Zhongba Cobalt-Manganese Deposit from the Shiqian Area,Guizhou

成冰系-埃迪卡拉系转折期是地球演化的一段重要变革时期,不仅发生了地球环境的骤变、生命的繁衍进化,而且在陡山沱组底部广泛沉积含锰(钴)白云岩,甚至在局部地区形成钴锰矿床,具有非常重要的理论意义和工业价值。以贵州石阡中坝钴锰矿为例,初步探讨矿床成因及其地质意义,获得如下认识:矿体主要呈似层状、透镜状产出陡山沱组底部,矿石类型主要为含钴锰黏土岩、含钴锰白云岩,钴可能主要赋存于高价锰氧化物中。持续的热液活动为成矿提供了重要物质基础,风化作用改造对成矿具有重要控制作用,初始阶段沉积的含钴锰白云岩部分遭受风化形成含钴锰黏土岩,这一过程有利于钴的进一步富集成矿。初步认为扬子板块陡山沱组底部钴锰矿化现象发育,具有钴锰矿找矿的潜力和前景。

The Cryogenian-Ediacaran transition is an important turning duration in the history of earth.In this duration,the sudden change of the earth environment and the evolution of life occurred,the manganese-cobalt-containing dolomite was widely deposited at the bottom of the Doushantuo Formation,further,the cobalt-manganese ore deposits in some local areas were formed,which has very important theoretical significance and industrial value.In this study,we took the Zhongba cobalt-manganese deposit in Shiqian,Guizhou as an example,the ore deposit's genesis and geological significance were investigated.The main knowledge obtained in this study is as follows.The ore bodies are mainly stratiform-like and lens-like,which occur in the bottom of Doushantuo Formation.The main types of ore are cobalt-manganese-containing clay rock and cobalt-manganese-containing dolomite,and the cobalt may mainly occur in manganese oxides.The continuous hydrothermal activities are an important substance basis for mineralization,and the weathering plays an important role in controlling the mineralization process.During this process,some of the cobalt-manganese dolomite is weathered,resulting in the formation of cobalt-manganese clay rock,which is conducive to the further enrichment and mineralization of cobalt.Based on the above-mentioned analysis,we preliminarily believed that the cobalt-manganese mineralization is widely developed at the bottom of Doushantuo Formation in Yangtze Plate,which suggested a mineralization prospecting potential in the present layer.