ABSTRACT
Textural and radiocarbon analyses of vibracore sediments show that the outer continental shelf within the Baltimore Canyon Trough area is mantled by shelly, poorly sorted, medium to coarse sand of Holocene age. This sand sheet is underlain by muddy Pleistocene sediments, the top of which can be traced laterally in high-resolution seismic-reflection profiles. Detailed acoustic surveys within two relatively large subareas show that the thickness of the potentially mobile sand cover on this part of the shelf ranges from less than 1 to 20 m, averages between 5 and 7 m, and is related closely to the bottom morphology. Estimates of the volume of sand at the seafloor vary between 8 × 106 and 11 × 106 MT/sq km. This study shows that the irregular distribution of sand in the Baltimore Canyon Trough area reflects relict fluvial and nearshore processes, the configuration of the Pleistocene substrate, as well as modern sediment movement.
