Structure and evolution of Baltimore Canyon Trough and Georges Bank Basin

Conference · Tue Jan 01 04:00:00 EST 1985 · Geol. Soc. Am., Abstr. Programs; (United States)

OSTI ID:6597215

Grow, J A; Schlee, J S; Klitgord, K D; Hutchinson, D R

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-
• Conference Information: Journal Name: Geol. Soc. Am., Abstr. Programs; (United States) Journal Volume: 17
• Country of Publication: United States
• Language: English

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ATLANTIC OCEAN
CONTINENTAL MARGIN
DEPOSITION
EARTH CRUST
FEDERAL REGION I
GEOLOGIC HISTORY
GEOLOGIC STRUCTURES
GEOLOGY
GEOPHYSICAL SURVEYS
GEORGES BANK
MAGNETISM
MASSACHUSETTS
NORTH AMERICA
OCEANIC CRUST
ORIGIN
PALEOMAGNETISM
PLATE TECTONICS
RIFT ZONES
SEA BED
SEAS
SEDIMENTARY BASINS
SEDIMENTS
SEISMIC SURVEYS
STRATIGRAPHY
SUBMARINE CANYONS
SURFACE WATERS
SURVEYS
TECTONICS
USA