Phanerozoic geological evolution of the Equatorial Atlantic domain

Christophe Basile (1) , Jean Mascle (2) , René Guiraud (3)

1 LGCA - Laboratoire de Géodynamique des Chaines Alpines
2 GEOAZUR 6526 - Géoazur
3 LDL - Laboratoire Dynamique de la Lithosphère

The Phanerozoic geological evolution of the Equatorial Atlantic domain has been controlled since the end of Early Cretaceous by the Romanche and Saint Paul transform faults. These faults did not follow the PanAfrican shear zones, but were surimposed on Palaeozoic basins. From Neocomian to Barremian, the Central Atlantic rift propagated southward in Cassiporé and Marajó basins, and the South Atlantic rift propagated northward in Potiguar and Benue basins. During Aptian times, the Equatorial Atlantic transform domain appeared as a transfer zone between the northward propagating tip of South Atlantic and the Central Atlantic. Between the transform faults, oceanic accretion started during Late Aptian in small divergent segments, from south to north: Benin-Mundaú, deep Ivorian basin-Barreirinhas, Liberia-Cassiporé. From Late Aptian to Late Albian, the Togo-Ghana-Ceará basins appeared along the Romanche transform fault, and Côte dÍvoire-Parà-Maranhão basins along Saint Paul transform fault. They were rapidly subsiding in intra-continental settings. During Late Cretaceous, these basins became active transform continental margins, and passive margins since Santonian times. In the same time, the continental edge uplifted leading either to important erosion on the shelf or to marginal ridges parallel to the transform faults in deeper settings.

Mots clés: Equatorial Atlantic; Rifting; Transform margin

Domaines: Tectonique

Christophe Basile, Jean Mascle, René Guiraud. Phanerozoic geological evolution of the Equatorial Atlantic domain. Journal of African Earth Sciences, 2005, 43, pp.275-282. ⟨10.1016/j.jafrearsci.2005.07.011⟩. ⟨hal-00015514⟩