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(Article of periodic en Anglais - 1979)

Document title

Evidence for late Precambrian plate tectonics in West Africa

Abstract

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.

Source

Article of periodic

published at : Nature London

Editor :

Millesime : 1979, vol. 278, no5701 [pp. 223-227]

Bibliographic references : 33 réf.

Language

Anglais

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