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

Jorge R. Sanchez1, Fabrice Gaumet2, Jean Letouzey3, Isabelle Moretti4, Jean-Claude Lecomte2, Caroline Magnier2, S. Zimine5, José O. Lopez6, and Juan G. Lopez7. (1) Centro de Investigaciones del Petroleo (CEINPET), Washington #169, Cerro, Havana, 12000, Cuba, phone: 53 7 577309, jsanchez@ceinpet.cupet.cu, (2) Geology-Geochemistry Department, Institut Français du Pétrole, 1 & 4, Avenue de Bois-Préau, 92852 Rueil Malmaison Cedex, France, (3) Geology-Geochemistry, Institut Français du Pétrole, 1-4 avenue de Bois Préau, Rueil Malmaison, 92852, France, (4) Géologie-Géochimie, Institut Français du Pétrole, 1-4 avenue du Bois Préau, Rueil Malmaison, 92852, France, (5) Compagnie Générale de Géophysique, Massy, France, (6) CEINPET, Wasington No. 169, Cerro, Ciudad de la Habana, CP.12000, Cuba, (7) Centro de Investigaciones del Petroleo, Washington #169, Cerro, Havana, 12000, Cuba

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.