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

破译卡普瓦尔和津巴布韦克拉通的早期太古宙地壳历史

• 批准号: 277088755
• 负责人: Professor Dr. Alfred Kröner (†)
• 金额: --
• 依托单位: Institut für Geowissenschaften
• 依托单位国家: 德国
• 项目类别: Priority Programmes
• 财政年份: 2015
• 资助国家: 德国
• 起止时间: 2014-12-31 至 2018-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/277088755?language=en
• 关键词: Deciphering; early; Archaean; crustal; history

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.

该项目将利用实地调查、单锆石测年、地球化学以及Hf和Nd同位素系统，调查津巴布韦和Kaapvaal东部两个鲜为人知的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的锆石年龄>3.6 Ga，我们的目标是了解这些岩石发生的岩浆，构造和变质历史。在Kaapvaal克拉通东部，在斯威士兰中部的一片片麻岩中，我们将研究一个包含>3.6 Ga的碎屑锆石的麻粒岩相表壳岩序列以及周围的花岗岩类片麻岩，我们也预计其中有非常古老的地壳成分。目的是确定古锆石的源区，并了解这一古锆石与古片麻岩杂岩的关系斯威士兰和邻近的巴伯顿绿岩带和卡普瓦尔克拉通的其他部分。总的来说，该项目有助于了解早期西太平洋地壳演化，并设想与涉及南部非洲的其他SPP 1833项目密切合作。