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.

The sediment data presented in this data layer were from a geochemical study sited in Great Bay estuarine system of New Hampshire. Textural data were used to support interpretations of trace metal distributions. The analog data were originally converted into digital form for inclusion in a Gulf of Maine Contaminated Sediments Database.

The sediment data presented in this data layer were from an ecological study sited near the Portsmouth Naval Shipyard, Kittery, Maine. The analog data were originally converted into digital form for inclusion in a Gulf of Maine Contaminated Sediments Database.

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.

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.

The data in this layer are from a number of published and unpublished sets produced by the Bigelow Laboratory. The source projects were conducted primarily to examine contaminant (e.g. trace metals, PAHs) distributions, but also produced sediment textural data. The data were originally converted into digital format for inclusion in the Gulf of Maine Contaminated Sediments Database.

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.

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 data in this layer were generated as part of an environmental impact statement evaluating the construction of a proposed 250,000 barrel per day oil refinery and marine terminal. Permits for this facility, which would serve the Eastport, Maine area, were requested by the Pittston Company of New York.

Cape Cod Bay, lying on the Massachusetts coast partly enclosed by Cape Cod, is in a glaciated region of low relief. Coarse sediments generally occur in areas exposed to wave and current action as in shallow water near shore or on shoals, and in the deep channel north of the tip of Cape Cod, which is swept by tidal currents. Fine sediments are restricted to the deeper water in the central portion of the Bay, and to the small well-protected embayments of the shore. Although Hough (1942) is available as part of the NGDC Deck 41 Database, additional data from the original report were manually entered and, therefore, this file is unque.