Publications

Unusually high abundances of sponges and gorgonian corals, covering as much as 25% of the bottom, occur at depths greater than 3.5 km on the Blake Spur, a rocky cliff-dominated feature on the western Atlantic continental margin. This is the first report of such high abundances of megafauna from a non-hydrothermal or otherwise chemosynthetically enriched site in abyssal depths. Animal...

This [summary of] U.S. Geological Survey Open-File Report 92-585 contains a listing of publications authored or co-authored by members of the Branch of Atlantic Marine Geology during 1991. Results of Branch investigations are distributed in a variety of ways, including maps, journal articles, abstracts and U.S.G.S. publications. Copies of U.S.G.S. Open File Reports may generally be...

No abstract available.

Continental shelves are typically covered by relatively shallow waters (

An analysis of 179 mass movements on the North American Atlantic continental slope and upper rise shows that slope failures have occurred throughout the geographic extent of the outer margin. Although the slope failures show no striking affinity for a particular depth as an origination level, there is a broad, primary mode centered at about 900 m. The resulting slides terminate at almost...

No abstract available.

As part of the expedition GANOVEX VI 1990/91, the Bundesanstalt für Geowissenschaften und Rohstoffe (BGR), the Alfred Wegener Institute for Polar and Marine Research (AWI), and the United States Geological Survey (USGS) carried out an airborne magnetic survey over the northwestern Ross Ice Shelf and McMurdo Sound between Ross Island, the Transantarctic Mountains, and Minna Bluff. The...

No abstract available.

Broad-range side-scan sonar (GLORIA) images and single- and multi-channel seismic reflection profiles demonstrate that the margin of north-western Hispaniola has experienced compression as a consequence of oblique North American-Caribbean plate convergence. Two principal morphological or structural types of accretionary wedges are observed along this margin. The first type is...

A 2,500-km2 area of sea floor on the south-eastern flank of the Greater Antilles Outer Ridge north of the Puerto Rico Trench displays anomalously high acoustic backscattering properties on GLORIA longrange sidescan-sonar data. Previously collected dredges, bottom photographs, and sediment cores indicate the presence of Fe-Mn nodules within the area of high backscatter. We were able to...

Gas bubble are present in sediments covering approximately 30% of the main stem of Chesapeake Bay, with bubbles occurring at the sediment-water interface in 18% of the main stem sediments. This biogenic gas is found either in the sediments in the lower salinity reaches of the Bay, or confined to sediments which overline infilled palaeodrainage channels formed during the Wisconsinan low...

The Mobil 312-1 hydrocarbon exploratory well, southeastern Georges Bank Basin penetrated a section entirely composed of sedimentary rocks that range from Middle to Pliocene age. Carbonates are the dominant lithologies in the intervals at 6096-3444 m, 2560-2096 m and 1067-887 m; siliciclastics make up most of the remaining section. Although inferred paleoenvironments range primarily from...