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The AAPG/Datapages Combined Publications Database

AAPG Bulletin


Volume: 65 (1981)

Issue: 5. (May)

First Page: 941

Last Page: 941

Title: Mesozoic Carbonate Platforms and Banks of Eastern North American Margin: ABSTRACT

Author(s): Lubomir F. Jansa

Article Type: Meeting abstract


The Jurassic-Lower Cretaceous carbonate platforms and banks form a discontinuous belt extending from the Grand Banks to the Bahamas, a distance of over 6,000 km. Six types of carbonate buildups are recognized that document the variability of depositional, paleo-oceanographic, and tectonic processes on the eastern North American margin. The texture of the carbonates closely resembles recent deposits of the western Great Bahama Bank in that oolitic grainstones were present near the shelf edge, and skeletal, peloid wackestones and mudstones (biomicrites) were deposited in the inner part of the platform. Coral-stromatoporoid and sponge bioherms were rare constituents of the carbonate banks.

The thickness of carbonate buildups progressively increases southward along the margin attaining a thickness of more than 5 km in the Bahamas. The platforms also become younger southward, which is thought to reflect the northward movement of less than 1.5 cm/year of the North American plate. The carbonate platforms were seeded over the continental basement following the taphrogenic period of plate tectonics.

The building of carbonate ramps characteristic of the Early Jurassic began during a transitional period between continental rifting and early drift of the continental plates in the North Atlantic. The second stage in construction of the carbonate platforms and offshore banks proceeded mainly after separation of the continental plates.

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Copyright 1997 American Association of Petroleum Geologists