A reconnaissance survey of that part of the Scotian Shelf extending from Halifax to Digby Nook was conducted during October, 1961, in order to determine the nature, distribution, and source areas of the bottom sediments. In general, the fine grained deposits of silt and clay (pelite) are found in the basins on the shelf as well as in the deeper water at the upper edge of the continental slope. Coarse grained deposits characterize topologically high areas and along the shelf margin.

Short cores were collected on the continental rise off Georges Bank. The character of the sediments and measured bottom currents show that the Western Boundary Undercurrent is a significant factor in sediment transport and deposition along the east coast continental rise. Size data for the sand and mud fractions were estimated by the compilers by subtracting the percent carbonate (composed largely of sand-sized planktonic foraminifera) from the coarse fraction. Silt and clay were not differentiated; the fine fraction is reported as mud.

The sediments and geomorphology of a portion of the northeastern continental shelf between Hudson Canyon and Georges Bank have been investigated. Wave-cut terraces at 13, 45, 65, and 80 fathoms indicate four former low sea levels, while concentrations of beach ridges around 35 fathoms reveal a fifth. The pre-Holocene drainage pattern, still exposed over part of the area, shows that Block Channel was the main stream system which drained most of southern New England. The surface sediments on the western part of the study area are Late Pleistocene fluvial deposits. Overlying these coarse deposits in the central part of the outer shelf is a sandy silt facies that is also relict. The youngest facies and the only area of present deposition, is in the northeastern part where sand eroded from Nantucket Shoals is being deposited on the shelf.

Surficial geologic maps play and important role in understanding the present sea floor and the processes that shape it. Between 1984 and 1991, over 1,700 bottom sample stations were occupied in the northwestern Gulf of Maine. Although the data were originally collected for a variety of research projects, contracts, and graduate student theses, they were eventually compiled as part of a Maine Geological Survey and University of Maine program to map the inner continental shelf of this region.

Gravel, sand, silt, and clay contents were determined for samples from Narragansett Bay and the adjacent Rhode Island Shelf. In the Narragansett Bay system, clayey silt and sand-silt-clay are the most abundant sediments. Sand is abundant locally and on the inner shelf. In general, toward the lower passages of the Bay the sediments show a progressive change to coarser textures.

The sediment data contained in this set were produced as part of the site description and monitoring phases of an aquaculture demonstration project. The site is located off the coast of New Hampshire in the Gulf of Maine.

A seismic reflection survey with concurrent bottom sampling was conducted in western Massachusetts Bay to obtain information on bottom topography and sediments, subbottom structure and composition, and the location of sand deposits potentially usable for restoration and nourishment of nearby beaches. Primary sediment data was derived from 43 cores. The predominant sediments of the surface and shallow subsurface deposits in the study area are fine sand, sand and gravel, and clayey silt. Sand suitable for beach restoration and nourishment on the contiguous coast occurs only locally and in generally small quantity relative to other sediments of the study area.

Two 21-day field operations were conducted in 1997 and 1998 in the estuaries and on the inner continental shelf off the northern Oregon and southern Washington coast. These cruises aboard the R/V Corliss were run in order to generate reconnaissance maps of the seafloor geology and the shallow subsurface stratigraphy using sidescan-sonar and seismic-reflection mapping techniques. The 1998 cruise also collected sediment grab samples, bottom photographs, and video images to verify the sidescan-sonar imagery and to document the seafloor geology. The combination of these data with previously collected sediment sample data (Robert, 1974; Nittrouer, 1978; and Smith et. al., 1980) has been used to define the extent and lithology of shelf sediments associated with the Columbia River littoral cell. This work is one component of a larger project studying the erosion of the Washington Oregon coasts and is being coordinated by the U.S. Geological Survey and the Washington State Department of Ecology. The reasons for collecting these data are to provide a regional synthesis of the offshore geology for this project and to support a wide variety of management decisions and to provide a basis for further process-oriented investigations.

The data in this set are part of the "Ocean Pulse" benthic studies that were conducted on the U.S. northeast shelf by the National Marine Fisheries Service. This data set represents only those data collected as part of this program during 1981-1982 and off New England. Those stations occupied in the New York Bight are not included. Although chemical analyses (organic carbon and total Kjeldahl nitrogen) were also conducted, only textural descriptions are included here.