Sources and distribution of surficial silt, eastern US Atlantic continental shelf

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

OSTI ID:6457223

Leschak, P; Prusak, D; Mazzullo, J

A study of the source and distribution of the surficial sediment on the eastern US Atlantic continental shelf between Cape Hatteras and Nova Scotia reveals that there are three major sources of silt on this shelf. One source is the unconsolidated Cretaceous and Tertiary coastal plain strata, represented by well-rounded and equant quartz grains which have been smoothed and rounded by chemical processes. A second source is the late Pleistocene glacial deposits, represented by highly angular and elongate quartz grains produced by mechanical fracture and breakage. A third source is the Paleozoic and Mesozoic lithified sedimentary and crystalline rocks of the Appalachians, represented by moderately angular and irregular quartz grains with crystalline and pseudocrystalline nodes. The distributional patterns of the three silt types relative to those from coarser sediments from the same sources shows evidence for the extensive reworking of fine-grained sediments on the shelf since the Holocene transgression. In general, coastal plain-derived silt dominates the shelf sediments from Cape Cod southward to Cape Hatteras; glacially-transported silt dominates the shelf sediments north of Cape Cod; and sedimentary/crystalline-derived silt is found in variable quantities throughout the entire study area. These three silt types were presumably redistributed by late Pleistocene as well as modern processes of sedimentation on the shelf.

• Research Organization: Texas A and M Univ., College Station (USA)
• OSTI ID: 6457223
• 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

Related Subjects

58 GEOSCIENCES
580100* -- Geology & Hydrology-- (-1989)
580300 -- Mineralogy
Petrology
& Rock Mechanics-- (-1989)
ATLANTIC OCEAN
CONTINENTAL MARGIN
CONTINENTAL SHELF
DEPOSITION
EROSION
GEOLOGIC HISTORY
GEOLOGY
NORTH AMERICA
ORIGIN
PETROLOGY
SEAS
SEDIMENTATION
SEDIMENTS
SILT
SURFACE WATERS
USA