Syn-Rift Systems Evolution of the Cuban Northwest Offshore (Deep Waters)

Sanchez, Jorge R.¹, Fabrice Gaumet², Jean Letouzey², Isabelle Moretti², Jean-Claude Lecomte², Caroline Magnier², S. Zimine³, José O. Lopez¹, Juan G. Lopez¹ (1) Centro de Investigaciones del Petroleo (CEINPET), Havana, Cuba (2) Institut Français du Pétrole, Rueil Malmaison Cedex, France (3) Compagnie Générale de Géophysique, Massy, France

This contribution presents the syn-rift tectono-paleogeographic evolution of the south­eastern Gulf of Mexico (Cuban North-West offshore) by using seismic stratigraphy and the input of Cuban geology where is recorded in outcrops and wells.

The seismic stratigraphy interpretation is based on a detailed analysis of multifold seis­mic data of the CGG survey carried out in the year 2000.

Two tectono-stratigraphic phases are considered: a) Syn-rift system JI (Lower Jurassic to Middle Jurassic), in relation with the rifting stage between Laurentia (North American plate) and Gondwana (South American and African plates); it ended with late-rift Callovian salt deposits, mainly developed in the Gulf of Mexico and along the proto-Caribbean margin too. b) Syn-rift system JII (Oxfordian to Berriasian),which corresponded to the ocean spreading in the Gulf of Mexico and related rift propagation between Yucatan and Florida.

The sequence A was formed during the syn-rift system I, while the syn-rift system II started with the deposition of sequence C. The syn-rift character of sequence A (Upper Triassic?-Mid Jurassic?) is evidenced in the northern Central basin, as along the Yucatan and Florida margins. Clastics were deposited in grabens and half-grabens. Anhydrites and dolomites seem to be inter-bedded with clastics in southern domains.

The sequence B (Callovian) is thin to the north and only deposited in two restricted marine intra-continental basins. Hyper-saline conditions prevailed during the sequence B deposition. A thicker unit extends to the Florida domain.

There are evidences of the potential of a deep petroleum system in the silici-clastic rift sequence. The shales from the Middle Jurassic syn-rift section appear to have an initial good potential.