Geology of the United States' Seafloor presents new, definitive studies of the seafloor adjacent to various regions of the United States--the West Coast, East Coast, Alaskan margin, Gulf of Mexico and the Caribbean--from the GLORIA long-range sidescan sonar images, complementary seismic profiling, and magnetic surveys. This spectacular dataset provides a new insight into the structural evolution of the seafloor, and the sedimentary processes that have modified it. Such a comprehensive interpretation of the images, in the context of the geology and geological processes of the seafloor, is presented here for the first time. New concepts have emerged and scientists have garnered much new knowledge as a result of this surveying. Geology of the United States' Seafloor will be useful to the broad range of advanced students and scientists studying the continental margins and the seafloors of the world.

This report presents high-resolution geophysical data, interpretive maps, and a preliminary discussion about the oyster habitat and estuary-floor geology within Apalachicola Bay, Florida (fig. 1). During two research cruises, conducted in 2005 and 2006, approximately 230 km? of the bay floor were surveyed using interferometric-bathymetry, sidescan-sonar, and chirp seismic-reflection techniques. The research was conducted as part of a cooperative program between the U.S. Geological Survey (USGS), the National Oceanic and Atmospheric Administration Coastal Services Center (CSC), and the Apalachicola Bay National Estuarine Research Reserve. The Apalachicola Bay National Estuarine Research Reserve was established in 1979 to provide opportunities for long-term monitoring and research to provide a basis for more informed coastal management decisions for this estuary. Apalachicola Bay is the largest oyster fishery in Florida (Whitfield and Beaumariage, 1977), and the primary objective of this program is to develop a suite of maps that define oyster habitat distribution and estuary-floor geology within the bay. The resulting maps will assist in effective management of oyster resources and provide a reference geologic framework for future scientific and applied research.