中南部非洲镍矿成矿规律及资源潜力分析

Metallogeny and Resource Potential of Nickel Deposits in Mid-Southern Africa

中南部非洲镍矿资源丰富,大体可分为岩浆型和风化壳型2种预测类型。本文在对中南部非洲243处镍矿床/点资料系统收集整理的基础上,将产出的镍矿初步划分为新太古代、古元古代、中元古代和新元古代4个成矿期,南非卡普瓦尔北缘古元古代Cr-Ni-Cu(PGE)成矿带、津巴布韦大岩墙新太古代NiCr(PGE)成矿带、博茨瓦纳弗朗西斯敦—赛莱比—皮奎新太古代Ni-Cu-Au成矿带、赞比亚赞比西津巴—卢萨卡新元古代Au-Ni-Cu成矿带、坦桑尼亚乌本迪—乌萨嘎仁古元古代Ni-Cu成矿带和坦桑尼亚—布隆迪基巴拉中元古代Ni-Cu-Co成矿带共6个成矿带,从整体上构成了北东向的中南部非洲巨型镍矿带;并分别对研究区内典型的与大陆边缘裂解有关的Ni-Cu(PGE)矿床、与造山带伸展背景有关的Ni-Cu矿床、与地幔柱有关的Ni-Cu(PGE)矿床和风化壳型镍矿床的矿床地质特征和成矿模式进行了研究。综合研究表明,布什维尔德矿集区、津巴布韦大岩墙矿集区、博茨瓦纳弗朗西斯敦—赛莱比—皮奎矿集区、坦桑尼亚—布隆迪穆松加迪—卡邦加矿集区镍矿资源潜力巨大,找矿前景优越。

Nickel resources are rich and composed of magmatic type and weathering crust type for prediction in the Mid-Southern Africa.Four metallogenic epochs of nickel deposits and mineralized occurrences have been divided based on the data of 243 nickel deposits and their mineralization,which are Neoarchaean,Paleoproterozoic,Mesoproterozoic,and Neoproterozoic.Six metallogenic belts include Kaapvaal Paleoproterozoic Cr-Ni-Cu（PGE）metallogenic belt in South Africa,Great dyke Neoarchaean Ni-Cr（PGE） metallogenic belt in Zimbabwe,Francistown-Selebi-Phikwe Neoarchaean Ni-Cu-Aumetallogenic belt in Namibia,Zambezi Ziemba-Lusaka Neoproterozoic Au-Ni-Cu metallogenic belt in Zambia,Wubendi-U Sagar Jin Mesoproterozoic Ni-Cu metallogenic belt in Tanzania,and Kibara Neoproterozoic Ni-Cu-Co metallogenic belt in Tanzania.We discussed the typical characteristics and metallogenic models of the nickel deposits which related with the breakup of continental margin Ni-Cu（PEG）deposits,large igneous provinces related Ni-Cu deposits,and weathering crustal Ni-Cu（PEG）deposits.The comprehensive research shows that there are great Ni mineral resources potential and good prospects in Bushveld ore district,Great Dyke of Zimbabwe ore district,Francistown-Selebi-Phikwe ore district of Botswana,and Musongati-Kabanga ore district of Tanzania-Burundi.