Detailed seismic stratigraphic studies document the development of Lower Cretaceous platforms and margins along the Florida Escarpment and Jordan Knoll in the eastern Gulf of Mexico. Four different areas are characterized by relating seismic facies to depositional models: (1) northwest of DeSoto Canyon a rimmed platform margin with low paleo-relief (about 1,500 m over a distance of 20 km) grew in a stationary manner and developed an accretionary slope, (2) a rimmed platform with high paleo-relief (about 2,500 m over a distance of 6 km) is exposed along the Florida Escarpment from DeSoto Canyon south to about 24°30′N (this part of the platform margin also grew in a stationary manner but developed a bypass slope), (3) a rimmed platform margin with moderate paleo-relief evolved from about 24°30′N south to the Straits of Florida, and (4) an isolated platform with steep paleo-relief formed on a basement high at Jordan Knoll west of the Florida Escarpment. This platform also grew in a stationary manner and developed bypass slopes. The evolution of the various types of platform margins is related to their overall tectonic setting. Two episodes of platform drowning have been identified: (1) middle to late Albian(?) with the development of intrashelf basins and (2) middle Cenomanian when the platforms were terminally drowned due to a rapid change in relative sea level.

Erosional truncation of reflections along the base of the Florida Escarpment suggests that parts of the platform margin have retreated up to 2-5 km since the middle Cenomanian.

This content is PDF only. Please click on the PDF icon to access.

First Page Preview

First page PDF preview
You do not currently have access to this article.