Cenozoic seismic stratigraphy of the SW Bermuda Rise
The seismic Horizon A-Complex (Tucholke, 1979) readily explains reflector patterns observed along the western third of the Bermuda Rise; farther east, basement is much more rugged and gravity flows shed from local topographic highs complicate the stratigraphy. Distal turbidites on the southwestern Bermuda Rise onlap reflector A* from the west, suggesting early Paleocene mass wasting of the North American margin. Locally erosive bottom currents cut into the middle Eocene section of the SW Bermuda Rise; these northward flowing currents preceded those that formed reflector Au along the North American margin near the Eocene-Oligocene boundary. Southward flowing currents swift enough to erode the sea floor and to form reflector Au did not reach as far east as the SW Bermuda Rise. Instead, the main effect of these Au currents was to pirate sediment into contour-following geostrophic flows along the North American margin and to deprive the deep basin and the Bermuda Rise of sediment transported down-slope. Consequently, post-Eocene sediments away from the margin are fine-grained muds. Deposition of these muds on the SW Bermuda Rise was controlled by northward flowing bottom currents. The modern Hatteras Abyssal Plain developed in the late Neogene as turbidites once again onlapped the SW Bermuda Rise. Today, these deposits extend farthest east in fracture zone valleys and in the swales between sediment waves. Northward flowing currents continue at present to affect sediment distribution patterns along the western edge of the Bermuda Rise.
- Research Organization:
- Columbia Univ., Palisades, NY (USA)
- OSTI ID:
- 6456638
- 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
Similar Records
Late Quarternary evolution of the northern Hatteras Abyssal Plain. [LLW Ocean Disposal Program]
Sedimentation in the Kane fracture zone, western North Atlantic
Related Subjects
BERMUDA
CONTINENTAL MARGIN
SEISMIC SURVEYS
STRATIGRAPHY
TOPOGRAPHY
CENOZOIC ERA
EROSION
SEA BED
SEDIMENTS
SUBMARINE CANYONS
EUROPE
GEOLOGIC AGES
GEOLOGY
GEOPHYSICAL SURVEYS
ISLANDS
SURVEYS
UNITED KINGDOM
WESTERN EUROPE
580100* - Geology & Hydrology- (-1989)
580500 - Oceanography- (1980-1989)