南非西北省某铁锰矿床地质特征及成因浅析

矿区位于世界著名的南非波斯特马斯堡—卡拉哈里锰成矿带西北部边缘。铁锰矿体呈层状、似层状、透镜状产出,层位控矿特征明显;矿石具变晶结构,条带状构造;矿石矿物的主要成分为黑锰矿、褐锰矿、铁氧化物、菱锰矿、钙锰石等,脉石矿物主要为硅质和少量钙质;矿床成因类型为沉积变质型铁锰矿床,成因模型应属于上升流模型,即深海富锰铁水体在水流的带动下,上升至海盆陆架氧化区域富集,接收氧化沉积成矿(深部矿体)。之后在逆冲推覆过程中衍生一系列的次级逆冲断层,导致德兰士瓦超群在空间上的重复出现,形成现有的浅部逆冲推覆矿体特征。

Geological characteristics and genesis of Mukulu Fe-Mn deposit in northwest South Africa

The Mukulu mining area is located on the northwestern edge of the world-famous South Africa Postmasburg-Kalahari manganese metallogenic belt. The iron-manganese ore body is layered, layer-like, and lens-shaped, with obvious ore-controlling characteristics; the ore has a crystal structure and a strip structure; the main components of the ore mineral are black manganese, brown manganese, iron oxide, Rhodochrosite, permanganite, etc., the gangue minerals are mainly siliceous and a small amount of calcareous; the genetic type of the deposit is sedimentary metamorphic iron-manganese deposit, and the genetic model should belong to the upwelling model, that is, the deep sea ferromanganese-rich water body is driven by the current , Rising to the oxidized area of the continental shelf shelf enrichment, receiving oxidative sedimentary mineralization (deep ore body). Afterwards, a series of secondary thrust faults were derived during the thrust and overthrow process, which led to the repeated occurrence of the Transvaal supergroup in space, forming the existing characteristics of shallow thrust nappe bodies.