Evolution of Veatch, Washington, and Norfolk Submarine Canyons: Inferences from strata and morphology

Abstract

Investigations of Veatch, Washington, and Norfolk Submarine Canyons, on the eastern continental margin of the United States, resulted in a detailed assessment of their past and present geologic processes. Norfolk and Washington Canyons share such characteristics as similar levee geometry, stratigraphy, and mineralogy; Veatch Canyon differs from Norfolk and Washington Canyons in these respects. Seismic reflection profiles of all three submarine canyon heads indicate an erosional origin. Seismic profiles of Veatch Canyon's lower continental slope indicate a formation by depositional processes; in contrast, the continental-slope profiles of Washington and Norfolk Canyons reveal a history of alternating episodes of deposition and erosion. Cored sediments from Washington and Norfolk Canyons disclose recent, intermittent, down-canyon transport of sand to the continental rise. Bathymetric and seismic profiles suggest Veatch, Washington, and Norfolk Canyons have all been subjected to a minimum of two periods of development. Similar axial trends of Washington and Norfolk Canyons imply a common structural influence.