Evidence for late Precambrian plate tectonics in West Africa
Auteurs :BLACK, R.
CABY, R.
MOUSSINE-POUCHKINE, A.
BAYER, R.
BERTRAND, J. M.
BOULLIER, A. M.
FABRE, J.
LESQUER, A.
Description :
In the Gourma and Iforas regions (Mali) rifting occured around 800-850 Myr ago along the eastern margin of the West African craton with a triple point in Mali, the Gourma being interpreted as an aulacogen-Oceanic closure around 600Myr led to a collision between the passive continental margin of the West African craton and an active continental margin to the east displaying island arc and marginal trough volcano-clastic assemblages bordering a deformed continental mass intruded by a high-level batholith. The suture is marked by a string of positive gravity anomalies corresponding to the emplacement of ultrabasic and basic rocks including perhaps ophiolites. East-West shortening was accompanied by the translation onto the West African craton foreland of nappes including internal nappes displaying high pressure-low temperature metamorphism assemblages.
Type de document :
Article de périodique
Source :
Nature London, 1979, vol. 278, n°. 5701, p. 223-227, Références bibliographiques : 33 réf.
Date :
1979
Langue :
Anglais
Anglais
Droits :
Tous droits réservés © Prodig - Bibliographie Géographique Internationale (BGI)
Tous droits réservés © Prodig - Bibliographie Géographique Internationale (BGI)