High-resolution geologic mapping of the inner continental shelf: Nahant to Gloucester, Massachusetts
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Resource Abstract:
<p>This report presents high-resolution maps of the seafloor offshore of Massachusetts, from Nahant to Gloucester. Approximately
134 km² of the inner shelf were mapped with a focus on the nearshore region in water depths less than 40 m (fig. 1.1).
The maps were prepared as part of a cooperative mapping program between the U.S. Geological Survey (USGS) and the Massachusetts
Office of Coastal Zone Management (CZM). They are based on marine geophysical data, sediment sampling, and bottom photography
obtained on two research cruises carried out in 2003 and 2004. The primary objective of this program is to develop a suite
of seafloor maps that provide geologic information for management of coastal and marine resources. Accurate maps of seafloor
geology are important first steps toward protecting fish habitat, delineating marine reserves, and assessing environmental
changes due to natural or human impacts. The maps also provide a geologic framework for scientific research, industry and
the public.</p> <br /> <p>The organization of this report is outlined in the navigation bar along the left-hand margin of
the page. This is section 1, the introduction. Section 2 briefly describes the mapping products contained in this report and
has links to large-format map sheets, that can be viewed on line or downloaded. Section 3 is a description of the data collection,
processing, and analysis procedures used to create the map products. Section 4 examines the geologic framework and late Quaternary
evolution of the region, and presents two different strategies for mapping the complex seafloor. This report also contains
four appendices that include GIS layers of all data collected in this study, and copies of the sample and photographic data
used to validate the interpretations.</p>
Citation
Title High-resolution geologic mapping of the inner continental shelf: Nahant to Gloucester, Massachusetts