An Overview of Nickel Mineralisation in Africa with Emphasis on the Mesoproterozoic East African Nickel Belt (EANB)

摘要: Nickel production in Africa takes place principally Botswana, South and Zimbabwe, with much of the African Zimbabwean being a by-product platinum-group element mining Bushveld Complex Great Dyke. Several large nickel deposits have been discovered elsewhere but until recently, their development has hindered by political risk limitations energy transport infrastructure. Most continent is significantly underexplored respect to base metals, including area covered East Belt (EANB). The known EANB all occur mafic-ultramafic intrusive rocks Mesoproterozoicage Kibaran igneous event. These bodies take form medium layered intrusions, small dynamic magma conduits (chonoliths sills) dyke swarms. Laterite are developed over exposed dunite peridotite lithologies basal sequence larger whereas sulphide at chonoliths. Geochronological geochemical data suggests that intrusions formed single magmatic event (1350 1400 Ma) were derived from picritic parental magma, which was variably contaminated mid upper-crustal staging chambers metasedimentary rocks. As result, mineralisation most, grades tenors too low be considered economic foreseeable future. In 1970s, government-led regional surveys identified laterite deposit Musongati Burundi Kabanga northwest Tanzania. subsequently explored delineated companies, they remain undeveloped due distance coast lack now comprises total mineral resource 58 million tonnes grading 2.6% nickel. an overall 122 grade 1.4%