Deciphering the early Archaean crustal history in the Kaapvaal and Zimbabwe cratons

该项目将利用实地调查、单锆石定年、地球化学以及Hf和Nd同位素系统，研究津巴布韦和Kaapvaal克拉通东部两个鲜为人知地区最古老的地壳成分。在津巴布韦中部，我们的初步工作已经确定了几个花岗岩类片麻岩，锆石年龄为>3.6 Ga，我们的目的是了解这些岩石所在的地体的火成岩、构造和变质历史。在Kaapvaal克拉通东部，在斯威士兰中部的片麻岩地体中，我们将研究一个太古代的麻粒岩相表壳岩序列，其中含有碎屑锆石>3.6 Ga，以及周围的花岗质片麻岩，我们也期望在这些片麻岩中有非常古老的地壳成分。目的是确定古锆石的来源区域，并了解该古地体与斯威士兰古片麻岩杂岩、邻近的巴伯顿绿岩带和卡普瓦尔克拉通其他部分的关系。总的来说，该项目对了解早期太古宙地壳演化作出了贡献，预计将与SPP1833研究南部非洲的其他项目密切合作。

This project will investigate the oldest crustal components in two poorly known areas of the Zimbabwe and eastern Kaapvaal cratons, using field investigations, single zircon dating, geochemistry, as well as Hf and Nd isotopic systems. In central Zimbabwe, our preliminary work has identified several granitoid gneisses with zircon ages >3.6 Ga, and our aim is to understand the igneous, structural and metamorphic history of the terranes in which these rocks occur. In the eastern Kaapvaal craton, within a gneiss terrane of central Swaziland, we shall investigate an Archaean sequence of granulite-facies supracrustal rocks containing detrital zircons >3.6 Ga as well as the surrounding granitoid gneisses in which we also expect very ancient crustal components, The aim is to identify the source area of the ancient zircons and to understand the history of this ancient terrane in relation to the Ancient Gneiss Complex of Swaziland and the neighbouring Barberton Greenstone Belt and other parts of the Kaapvaal craton. Overall, this project is a contribution to understand early Archaean crustal evolution, and close cooperation with other SPP1833 projects dealing with southern Africa is envisaged.