--> Abstract: Petroleum Potential of Blake Plateau-Bahama Region of Atlantic Margin of North America, by Robert E. Sheridan; #90968 (1977).

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Abstract: Petroleum Potential of Blake Plateau-Bahama Region of Atlantic Margin of North America

Robert E. Sheridan

Great thicknesses of Triassic and younger sediments are observed seismically in the Blake Plateau-Bahama area. Basement is thought to be from 7 to 14 km deep below high-velocity carbonate rocks. Drilling data show ridgelike reflectors along the Blake Escarpment are Cretaceous reef-rim complexes. Deep wells indicate that this rim facies extends southeast along the Bahama platform margin. The Gulf Stream apparently has swept the continually subsiding Blake Plateau during much of the Cenozoic, creating this deeper water area while contour currents eroded the Blake-Bahama Escarpment and deposited muds to form the Blake-Bahama Outer Ridge. Deep-water Bahamian channels developed in the Cretaceous and Cenozoic between the accreting carbonate banks; while Jurassic salt apparently has domed in Exuma Sound.

The crustal type, oceanic versus continental, beneath the Blake Plateau-Bahamas is still problematic. Other geophysical data indicate that the igneous basement is about 10 km deep and that the crust is of intermediate seismic velocity and density. Red Sea-Afar Triangle crustal types might be the modern analog, agreeing with plate-tectonic reconstructions and the Atlantic-margin rifting in the Triassic-Jurassic.

The Blake-Bahama area has great petroleum potential. Fault structures, regional tilting over reef complexes, and possible salt domes offer possible traps. Porous-dolomite zones and cavernous limestones have been drilled, but flushing of these excellent reservoirs is unfavorable for Cretaceous and younger rocks being petroleum reservoirs. Jurassic carbonate targets offer potential reserves with carbonate sources being likely. Mexican Golden Lane-Poza Rica fields and Smackover analogies are possible.

AAPG Search and Discovery Article #90968©1977 AAPG-SEPM Annual Convention and Exhibition, Washington, DC