Kibaran Metamorphic Belt in Pan-African Domain of West Africa?

Abstract

THE Kibarides, characterized by radiometric ages in the range 1,300–800 m.y., were first recognized in the Congo Craton^1,2 of central and eastern Africa where the shield has not been overprinted by the 600 ± 150 m.y. Pan-African thermotectonic event. They comprise the Kibara and Karagwe-Ankolean metasedimentary cover and older reacted crystalline basement rocks, and major events in the Kibaran orogeny have been shown to have occurred between 1,300 and 1,180 m.y. ago^3,4. In southern Africa, within the Kalahari Craton^1,2, a second cratonic block with respect to the Pan-African event, similar age patterns have been found in the Namaqualand and Natal belts, and although these belts are dominantly granitic and gneissic in character, and lack metasedimentary sequences equivalent to the Kibara and Karagwe-Ankolean Groups, they have long been considered to be synchronous with the Kibarides⁵.