Abstract:
The deepwater area of the southeastern Gulf of Mexico (SEGOM) has basinal water depths ranging from 500 to 2000 meters and is subdivided into the maritime zones of the United States, Mexico and Cuba. This presentation reviews evidence from offshore, subsurface data for a latest Cretaceous-Paleogene forebulge and terminal collision between the Cuban arc at the leading edge of the Caribbean plate and thinned continental crust in the SEGOM maritime zones. During the late Jurassic, the SEGOM was a broad zone of rifting between North and South America that included deposition of Kimmeridgian-Tithonian marine shale and carbonate that forms excellent, widespread source rocks in this and other parts of the circum-Atlantic. Potential reservoirs overlying these source rocks include upper Jurassic to Cretaceous Cretaceous, deepwater clastic and carbonate rocks deposited in the passive margin phase that followed the earlier Jurassic rift and continental separation phase. Interpretations of seismic lines and well subsidence historys of DSDP wells drilled in the southeastern Gulf of Mexico show an abrupt shallowing of these passive margin rocks during the latest Cretaceous associated with the formation of a prominent, east-west trending arch north of Cuba. We interpret this feature as a tectonically-controlled forebulge in thinned continental crust of North America that culminated in the formation of an extensive, late Paleocene unconformity seen in offshore wells and the creation of a variety of potential structural and stratigraphic traps. Bending of the southern edge of North America created a foreland basin filled with Paleogene clastic sediments derived from the uplifted area of Cuba and onlapping the forebulge north of the collision zone. A major point is that this forebulge is a major regional feature that extends as far west at the Yucatan Peninsula and as far east as the Florida Keys. Following collision, the forebulge and foreland basin subsided rapidly and was eroded during the later Cenozoic by the Gulf Stream passing eastward from the SEGOM into the Atlantic.