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 Estuary, New Hampshire. 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.

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.

This data set contains sediment grain size and textural information from the Continental Margin Program. The program was a joint collaboration between the U.S. Geological Survey and the Woods Hole Oceanographic Institution during the 1960s to conduct a geological reconnaissance investigation of the continental shelf and slope off the Atlantic coast of the United States. Only those records with complete size analyses are included in this data set. Other stations where only lithologic descriptions are available have been excluded.

The data in this layer are from a study that evaluated and documented the historic and projected future dredging and dredged material disposal needs of the coastal rivers and harbors of the states of Maine and New Hampshire. Documentation of historic dredging and disposal activities was accomplished through the collection of data primarily from the files of the ACOE, New England Division, in Waltham, Massachusetts, supplemented by information from the states of Maine and New Hampshire and previously published reports. This historic dredging occurred between 1950-1993 and involved 499 dredging events.

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 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.

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 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.