PAN-AFRICAN EVENT AND FORMATION OF GONDWANA

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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.