Quaternary uplift on the southeastern coast of Cuba

Abstract

The southeastern coast of Cuba is bounded on the south by the Oriente Fault Zone that corresponds to the northern Caribbean plate boundary. By analyzing the coastal terraces of this region, we decipher the Quaternary uplift along the transform plate boundary over a ∼ 380 km long coastal stretch. We present a detailed mapping of uplifted coastal terraces and 18 new U/Th ages of corals. Late Quaternary uplift rates range from −0.02 ± 0.02 to 0.23 ± 0.07 mm.yr⁻¹. From west to east, the coastal sequences exhibit a maximum of 18 terraces culminating at 270 m on Cabo Cruz, 11 terraces reaching 250 m near Santiago de Cuba and 29 terraces up to 520 m on Punta Maísi. Coastal sequences reveal distinct tectonic regimes. In the west at Cabo Cruz, uplift results from the tilting of tectonic blocks separated by NE-SW-trending normal faults, to the north of an extensional step-over of the Oriente Fault Zone. In the central part, the uplift is associated with NW-SE folding linked to a transpressional relay zone of the Oriente Fault Zone and to the offshore E-W Santiago Deformation Belt. In the east, at Punta Maísi, uplift results from a north-dipping thrust close to the coast linked with the oblique collision of the Bahamas platform against Cuba. The intensity of coastal uplift and locations of relay zones seems related to lateral variations in rheology and thickness of the tectonic plates. The uplift of the coast of SE Cuba is controlled by the oblique collision of the Bahamas platform of the North America continental plate against the continental crust of the Caribbean plate to the east and the oceanic/continental transition of the Caribbean plate to the West.