Buried fluvial channels off New Jersey; did sea-level lowstands expose the entire shelf during the Miocene?
Buried fluvial channels off New Jersey; did sea-level lowstands expose the entire shelf during the Miocene?
Geology (Boulder) (March 1999) 27 (3): 203-206
- Atlantic Ocean
- buried features
- Cenozoic
- channels
- continental margin sedimentation
- continental shelf
- geophysical methods
- geophysical profiles
- geophysical surveys
- high-resolution methods
- Leg 174A
- Miocene
- multichannel methods
- Neogene
- New Jersey
- North Atlantic
- Northwest Atlantic
- Ocean Drilling Program
- ODP Site 1071
- ODP Site 1072
- ODP Site 1073
- paleogeography
- progradation
- sea-level changes
- sedimentation
- seismic methods
- seismic profiles
- sequence stratigraphy
- STRATAFORM
- surveys
- Tertiary
- United States
High-resolution multichannel seismic profiles from the New Jersey continental margin reveal that some middle to late Miocene sea-level falls exposed the entire continental shelf. At several sequence boundaries, fluvial channels occur landward of the clinoform breakpoints that mark paleo-shelf edges. The seismically observed progradation therefore resulted from sediment delivery to the shelf edge by rivers during lowstands. Suspended sediment crossing the relatively shallow water (30-40 m) shelf also fostered progradation during highstands. River systems reaching the outermost shelf were small and closely spaced; they approximated a line source of sediment. This finding helps to explain the observed linearity of Miocene shelf edges. Although these systems discharged near clinoform tops, they did not form canyons incising the clinoforms; such canyons were rare in this active depositional setting, in contrast to their prevalence on the modern continental slope.