Cenozoic tectonostratigraphic evolution of the strike-slip Cauto-Guacanayabo Basin, Eastern Cuba

Abstract

An integrated study of Cauto-Guacanayabo strike-slip basin has allowed establishing its tectonostratigraphic evolution. This work uses subsurface data (wells, seismic and gravimetric) and surface data (digital terrain model and geological mapping) to investigate the relations between sedimentary infill and tectonic activity. In the sedimentary infill, four tectonosequences have been recognized, which are constituted by 19 lithostratigraphic units which range in age from middle Eocene to Holocene, and are delimited by regional unconformities at the basin scale. In seismic reflection profiles, the thickness of the sedimentary record can exceed 2600 ms of double time (TWT), while the thickness cut by the boreholes reaches 2500 m in the northeast part of the basin. Each tectonosequence shows different geometries, thickness and number of depocenters. The predominant geometries in a mapping view are rectangular and elongated in the northeast-southwest direction. This evidences the complexity and compartmentalization of the sedimentary infill in the Cauto-Guacanayabo Basin. The coexistence of extensive and compressive structures, close to each other in the Cauto-Guacanayabo Basin, is associated with local transtensive and transpressive regimes. These regimes have been controlled by the left lateral activity of the Cauto-Nipe strike-slip fault and the Guacanayabo-Nipe tectonic corridor. The compressive structures are mainly located in the southern part to the northeast – southwest and east-northeast – west-southwest directions. In the northeast part of the basin, extensive structures with north – south, northeast – southwest and possibly northwest – southeast directions are common, while in the Gulf of Guacanayabo, there is evidence of lesser deformation. The structural patterns indicate that the most intense activity of the Guacanayabo-Nipe tectonic corridor took place during the middle Eocene. The tectonic activity of the corridor begins to wane in the upper Oligocene, which coincides with the transfer of slip to the Orient Fault, the current boundary between the Caribbean and North American plates.