Stratigraphy and structure of southern Blake Plateau, northern Florida Straits, and northern Bahama Platform from multichannel seismic reflection data

Journal Article · Tue Dec 01 00:00:00 EST 1981 · Am. Assoc. Pet. Geol., Bull.; (United States)

OSTI ID:5792654

Sheridan, R E ^[1]; Crosby, J T; Bryan, G M; Stoffa, P L

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1. Univ. of Delaware, Newark

Approximately 2,100 km of 24-fold multichannel seismic reflection data reveal much about the subsurface geology for a large part of the continental margin east of Florida. Discordance between the westward-dipping pre-breakup sediments and the eastward-sloping basement along the edge of the Blake Plateau is interpreted as an effect of a splinter of continental margin derived from the African plate by a spreading-center jump in the Middle Jurassic. Early rifting centered under the main part of the Blake Plateau became inactive, as a spreading-center jump shifted the active rift to east of the present Blake Escarpment along the Blake Spur magnetic anomaly. In the northern Florida Straits the data reveal that the breakup unconformity, underlain by Triassic-Lower Jurassic arkosic volcaniclastics, extends from southern Florida to the western Bahama Banks Back-reef platform deposits of limestones, dolomites, and evaporites of Late Jurassic to Albian age extend from the Blake-Bahama Escarpment westward beneath Florida. These deposits formed what once was a megabank extending over a wider area than the present smaller isolated Bahama Banks. Evidence of recurring scour by current erosion is found in the Florida Straits. Erosional events apparently occurred in the middle Cenomanian, middle Paleocene, early-middle Eocene, and Eocene-Oligocene, which coincidentally are times of lower eustatic sea level according to Vail et al (1977a). This evidence of Florida current scour indicates that the current was present as far back as the Cenomanian. Major faulting appears to have dropped the Northeast Providence Channel relative to the western Bahamas after the Albian. Submarine erosion and bank buildup created the channels and smaller relief features like Great Abaco Knoll beginning in about the Cenomanian. A carbonate bank margin and reef complex was present along the Bahama Escarpment since the Middle Jurassic. 22 figures.

• OSTI ID: 5792654
• Journal Information: Am. Assoc. Pet. Geol., Bull.; (United States), Vol. 65:12
• Country of Publication: United States
• Language: English

Related Subjects

58 GEOSCIENCES
BAHAMA ISLANDS
SEISMIC SURVEYS
STRATIGRAPHY
FLORIDA
CRETACEOUS PERIOD
DOLOMITE
EROSION
GEOLOGIC FAULTS
LIMESTONE
PLATE TECTONICS
REEFS
TECTONICS
TERTIARY PERIOD
ALKALINE EARTH METAL COMPOUNDS
CARBON COMPOUNDS
CARBONATE ROCKS
CARBONATES
CENOZOIC ERA
DEVELOPING COUNTRIES
GEOLOGIC AGES
GEOLOGIC STRUCTURES
GEOLOGY
GEOPHYSICAL SURVEYS
ISLANDS
MAGNESIUM CARBONATES
MAGNESIUM COMPOUNDS
MESOZOIC ERA
MINERALS
NORTH AMERICA
OXYGEN COMPOUNDS
ROCKS
SEDIMENTARY ROCKS
SOUTHEAST REGION
SURVEYS
USA
WEST INDIES
580201* - Geophysics- Seismology & Tectonics- (1980-1989)