南部非洲花岗岩型与伟晶岩型钽矿床地质特征

Geological characteristics analysis of granite type and pegmatite type tantalum deposits in southern Africa

钽作为一种重要的稀有金属矿产,广泛应用于各种工业领域。世界上的钽矿床成因主要为内生成矿,尤以花岗岩型和伟晶型最为重要,碰撞造山过程导致的多期次岩浆活动是有利的钽矿成矿环境。南部非洲钽矿资源丰富且品位高,主要为花岗岩型和伟晶岩型钽矿床,空间上主要分布在卡普瓦尔克拉通、刚果克拉通、津巴布韦克拉通以及基巴拉、泛非、达马拉等碰撞环境下形成的同造山—后造山构造带内,时间上主要集中在太古宙(2.85~2.58 Ga)、古元古代(2.48~2.0 Ga)、晚中元古代—早新元古代(1026~880 Ma)以及泛非活动期(500~440 Ma),且不同钽矿带内含钽矿物稀有及稀土元素分布特征差异较大。南部非洲发育大量与钽矿形成密切相关的花岗岩及伟晶岩岩体,资源潜力巨大,未来有望成为世界上主要的钽资源接续基地。

As an important rare metal mineral,tantalum is widely used in various industrial fields.Ta deposits in the world are mainly endogenous sources,especially granite and pegmatite.The multi-stage magmatic activities caused by collision orogeny are favorable environment for tantalum mineralization.Tantalum deposits in southern Africa are rich in resources and of high grade,they are mainly granite and pegmatite type tantalum deposits.Spatially,distributed in the Kaapvaal Craton,Congo Craton,Zimbabwe Craton and the Kibara,Pan-Africa and Damara tectonic belts formed under the collision environments.Mineralization occurs mainly in Archean(2.85~2.58 Ga),Paleoproterozoic(2.48~2.0 Ga),Late Mesoproterozoic—Early Neoproterozoic(1026~880 Ma)and Pan-African orogeny(500~440 Ma).The distribution characteristics of tantalum-bearing rare earth elements in different tantalum ore zones are quite different.There are a large number of granite and pegmatite intrusions closely related to the formation of tantalum deposits in southern Africa,with huge resource potentials and are expected to become the main tantalum resource succession base in the world in the future.