Structure and evolution of Baltimore Canyon Trough and Georges Bank Basin
The Baltimore Canyon Trough (BCT) and Georges Bank Basin (GBB) formed along the continental edge off the northeastern United States during early Mesozoic extensional rifting between Africa and North America and have continued to subside throughout the late Mesozoic and Cenozoic. The seaward edge of the marginal basins and the western edge of the oceanic crust are marked by the East Coast Magnetic Anomaly (ECMA), which lies between the present Outer Continental Shelf edge and the Upper Continental Rise. The landward edge of the basins is marked by a hinge zone of rotated fault blocks, where the depth to the basement increases abruptly. Sediment deposition within the two basins can be divided into synrift and postrift phases, the base of the relatively undisturbed postrift deposits being marked by a postrift unconformity (PRU). Prerift and synrift deposits (including evaporites) as much as 5 km thick can be seen below the PRU on some seismic profiles, but their base is difficult to resolve on seismic profiles, and their maximum thickness could be much greater. After sea floor spreading began, continued subsidence of the basins due to thermal cooling of the lithosphere and sediment loading resulted in the deposition of as much as 13 km of postrift sedimentary rocks in BCT and 7 km in GBB. Although the Jurassic carbonate shelf-edge system migrated 40 km seaward onto the oceanic crust off northern BCT, shelf edges have generally remained landward of the ECMA and have retreated about 10 to 20 km during the late Cenozoic.
- Research Organization:
- Geological Survey, Denver, CO (USA)
- OSTI ID:
- 6597215
- Report Number(s):
- CONF-8510489-
- Journal Information:
- Geol. Soc. Am., Abstr. Programs; (United States), Vol. 17; Conference: 98. annual meeting of the Geological Society of America, Orlando, FL, USA, 28 Oct 1985
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
CONTINENTAL MARGIN
SEDIMENTARY BASINS
SUBMARINE CANYONS
MASSACHUSETTS
GEOLOGIC HISTORY
ORIGIN
STRATIGRAPHY
ATLANTIC OCEAN
DEPOSITION
GEORGES BANK
OCEANIC CRUST
PALEOMAGNETISM
PLATE TECTONICS
RIFT ZONES
SEA BED
SEDIMENTS
SEISMIC SURVEYS
EARTH CRUST
FEDERAL REGION I
GEOLOGIC STRUCTURES
GEOLOGY
GEOPHYSICAL SURVEYS
MAGNETISM
NORTH AMERICA
SEAS
SURFACE WATERS
SURVEYS
TECTONICS
USA
580201* - Geophysics- Seismology & Tectonics- (1980-1989)
580100 - Geology & Hydrology- (-1989)