Linking Tectonic and Sedimentary Events in the Northern Caribbean and Southern Gulf of Mexico

Alejandro Escalona¹, Nordfjord, Sylvia², Paul Mann², William Galloway² (1)Jackson School of Geosciences, The University of Texas at Austin, Austin, TX  (2) University of Texas at Austin, Austin, TX

We review the tectonostratigraphic evolution of the early Cenozoic collisional and strike-slip suture zone between the exotic Caribbean plate and the southeastern Gulf of Mexico (GOM) using ~1000 km of regional seismic profiles acquired by The University of Texas at Austin in the 1970's. The study area includes the Straits of Florida and the continental margins of Cuba, Florida, and the Yucatan Peninsula. Correlations between the seismic lines and one well drilled by DSDP Leg 77 in 1980 constrain the character and timing of three main tectonic phases: 1) Middle Jurassic to Early Cretaceous rifting of the Yucatan, Florida and Cuban blocks is related to the breakup of western Pangea; rifts are half-grabens trending to the east and northwest and contain continental syn-rift deposits up to ~500 m in thickness; 2) the formation of the Paleogene Cuban fold-thrust belt is linked to the development of a 100-1000-m-thick foreland basin beneath the Straits of Florida and a NW-trending peripheral bulge separating the Straits of Florida from the deep GOM; this shortening event also inverted several Mesozoic rifts some as far as >100 km from the thrust front; the Paleogene Cuban clastic wedge is an ~1600 km2 feature extending from Cuba to the central GOM; this fan appears to be derived from a Cuban point source; and 3) large deepsea erosional features and constructional sediment drifts are related to the formation of the Oligocene-recent Loop Current-Gulf Stream that flows from the northern Caribbean into the Straits of Florida.