PAN-AFRICAN EVENT AND FORMATION OF GONDWANA

泛非事件和冈瓦纳大陆的形成

基本信息

批准号：
09041116
负责人：
SHIRAISHI Kazuyuki
金额：
$ 9.47万
依托单位：
NATIONAL INSTITUTE OF POLAR RESEARCH
依托单位国家：
日本
项目类别：
Grant-in-Aid for international Scientific Research
财政年份：
1997
资助国家：
日本
起止时间：
1997 至 1999
项目状态：
已结题

项目摘要

This collaborative study between South Africa and Japanese geologists who had been studying in the East Antarctica aims to investigate the crustal formation during Neoproterozoinc to early Cambrian and reveal the Pan African orogeny related to the formation of Gondwana. During the three years program we investigated many parts of South Africa. In particular, the Grenvillian Natal-Namaqualand Belt extending around the southern and southwestern margins of the Kaapvaal Craton of South Africa was throughly investigated. This Province connects with the Dronning Maud Land in the Antarctica and the Grenville Province of the North America. Sr and Nd isotopic studies obtained various formation ages and model ages of the granitic and metamorphic rocks from the Namaqualand area. The isotopically juvenile Tugela terrane, part of the Natal belt, consists of a heterogeneous assemblage of regionally metamorphosed mafic and felsic rocks. The Tugela terrane is divisible on the basis of lithology and structural style, from east to west, into four major thrust sheets. The lithologically and geochemically distinct thrust sheets that comprise the oceanic Tugela terrane were each derived from distinct tectonic settings. The Kotongweni tonalite and its wall rocks, preserved in the Tugela sheet, provide a record of middle Proterozoic magmatic arc development prior to the obduction of the Natal belt onto the Kaapvaal craton at about 1.1 Ga. In addition, we have obtained some "new" mineralogical and petrological data in the metamorphic rocks from the Proterozoic Natal-Namaqualand Mobile Belt and Archean Limpopo Mobile Belt. The comprehensive results obtainted through this study will be published in a Memoir of the National Institute of Poal Research in 2001.

南非和日本地质学家之间在东南极洲进行研究的这项合作研究旨在调查新元古代期间的地壳形成，以使其早期寒武纪，并揭示了与冈瓦纳形成有关的PAN非洲造口。在三年计划中，我们调查了南非的许多地区。特别是，对南非Kaapvaal Craton的南部和西南边缘延伸的Grenvillian Natal-Namaqualand皮带延伸。这个省与南极洲和北美格伦维尔省的莫德土地建立联系。 SR和ND同位素研究获得了来自纳马夸兰地区的花岗岩和变质岩石的各种形成年龄和模型年龄。同位素少年的tugela Terrane是纳塔尔带的一部分，由区域变质的镁铁质和鳞状岩的异质组成。 Tugela Terrane在从东到西的岩性和结构风格的基础上可以分开，分为四个主要的推力纸。在岩性和地球化学上不同的推力板上，包括海洋图格拉地层，均来自不同的构造环境。 The Kotongweni tonalite and its wall rocks, preserved in the Tugela sheet, provide a record of middle Proterozoic magmatic arc development prior to the obduction of the Natal belt onto the Kaapvaal craton at about 1.1 Ga. In addition, we have obtained some "new" mineralogical and petrological data in the metamorphic rocks from the Proterozoic Natal-Namaqualand Mobile Belt和Archean Limpopo移动带。通过这项研究获得的综合结果将于2001年在美国国家POAL研究所的回忆录中发表。