Open-File Report 2014-1220
Shallow Geology, Sea-Floor Texture, and Physiographic Zones of Buzzards Bay, Massachusetts
The USGS, in cooperation with CZM, compiled high-resolution geophysical datasets with full sea-floor coverage, which were supplemented with sediment samples and bottom photographs. Additional single-beam and lead-line bathymetric data from NOAA, as well as legacy geophysical and sample data, also provided subordinate information. The composite maps and GIS resulted in detailed interpretations and mapping of the shallow and surficial geology of Buzzards Bay.
The interpretations presented here represent a unique geologic dataset. Each of the interpretive maps contributes new insight into the geologic framework and sedimentary environments of Buzzards Bay at a resolution that was previously impossible because of a lack of high-resolution geophysical data. Interpretations of high-resolution geophysical data and sediment samples show that the shallow geologic framework and surficial geology of Buzzards Bay is a complex and variable distribution of sediments and geomorphic features that can be primarily attributed to the advances, occupations, and retreats of Wisconsinan glaciation and to deposition and reworking and deposition during the Holocene transgression. Glacial, marine, and terrestrial processes have acted on this region since the late Pleistocene, resulting in a complex geologic history and a heterogeneous sea-floor character. Glacial sediments within the entire region are locally overlain by fluvial, estuarine, and nearshore sand and mud.