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.

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 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 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.

The results of the sediment size analysis performed by the U.S.Naval Oceanographic Office Geological Laboratory for six Phleger gravity cores are presented in this data layer. Some of the data in this set were originally released as part of the Deck 41 Database available from the National Geophysical Data Center. The attribute for sediment classification was added by the compilers to make these size data more useful for mapping the regional surficial sediment distribution.

The data in this layer are from a number of published and unpublished sets produced by the Bigelow Laboratory.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.

This data set contains lithologic information on bottom sediments 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 without complete size analyses and only those stations from the Gulf of Maine, Georges Bank, and southeastern New England shelf and slope are included in this data set. Other stations where detailed textural analyses are available or are from other areas have been excluded. Furthermore, dredges were used to collect most of the bottom samples, resulting in winnowing that has resulted in lithologic descriptions that are texturally coarser than actually present. Care should be taken when using this dataset.

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.

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 study was undertaken to provide information on the characteristics and distribution of surficial sediments off the eastern United States. Accordingly, long traverses were run across the continental shelf and in most case carrying over the shelf break. This data set includes data from those 9 traverses which were conducted north of Virginia. These data constitute the first systematic sampling of the U.S. Atlantic margin to show the effects of environmental factors (e.g. increasing distance from shore, water depth) on the sediment distribution. Sampling was performed with a primitive grab sampler; navigational methods were not discussed in this report.