Vermont

Source of radionuclides in drinking water  Gregory Walsh is mapping the Barre West 7.5-minute quadrangle in cooperation with the Vermont Geological Survey (VGS), in order to determine possible bedrock geologic sources of radionuclides found in local drinking-water supplies.  The 1:24,000-scale bedrock geologic mapping will be done in conjunction with ground-based gamma ray spectrometer readings on outcrops.

State geologic map  Work is underway to publish a 1:100,000-scale bedrock geologic map of Vermont. The new map will be published jointly by the State of Vermont Agency of Natural Resources (VTANR), Vermont Geological Survey (VGS) and the U.S. Geological Survey (USGS) as the result of a cooperative Federal and State project in the USGS National Cooperative Geologic Mapping Program.  Nicholas Ratcliffe and VGS geologists are compiling the geologic data for the 1:100,000-scale state map, which will be in two large sheets.  Publication is scheduled for 2004-2005.  A digital version of the 1:100,000 compilation will also be published.

Recent geologic mapping, conducted over the past 15 years by the USGS, VGS, and University cooperators at scales of 1:24,000 or larger, will cover approximately 65 percent of the State. Since the inception of the Vermont-USGS Cooperative Geologic Mapping Project the USGS has published a number of 7.5 minute quadrangle-scale (1:24,000) bedrock geologic maps in Vermont. An index map and list of the published quadrangles shows quadrangles where current work is in progress.

An integral part of the project has been the development of a digital bedrock geologic map database of recently completed mapping. The initial development of the database established the ground rules and procedures for development of a statewide database that is compatible with Vermont's existing GIS structure. The database development and compilation of geologic information is a cooperative effort conducted by the USGS, VGS, and the Office of Information Management Services at the Vermont Agency of Natural Resources. The database contains information on the distribution and location of bedrock geologic units, outcrops, faults, foliations, cleavages, joints, and mines and quarries. To date, the USGS and the VGS have published more than 30 7.5 minute quadrangles as digital bedrock geologic maps in an Open-File Report format. The database is maintained by the Vermont Geological Survey. The reports are available as colored paper maps and Arc/Info digital files. Contact the Vermont Geological Survey for more information.

Recent geologic mapping in Vermont, conducted over the past 15 years by the USGS, VGS, and University cooperators has resulted in a number of 1:24,000-scale (7.5-minute quadrangle) published USGS bedrock geologic maps and USGS and VGS digital bedrock geologic maps.  This 15-year mapping effort has resulted in great advances in our knowledge of the tectonic history of the northern Appalachians. 

Recent Papers:

Ratcliffe, N.M., and Armstrong, T.R., 2001, Bedrock geologic map of the Saxtons River 7.5´ x 15´ quadrangle, Windham and Windsor Counties, Vermont: U.S. Geological Survey Miscellaneous Investigations Series Map I-2636, scale 1:24,000.

Walsh, G.J., and Falta, C.K., 2001, Bedrock geologic map of the Rochester quadrangle, Rutland, Windsor, and Addison Counties, Vermont: U.S. Geological Survey Miscellaneous Investigations Series Map I-2626, scale 1:24,000.

Ratcliffe, N.M., 2000, Bedrock geologic map of the Chester quadrangle, Windsor County, Vermont: U.S. Geological Survey Miscellaneous Investigations Series Map I-2598, scale 1:24,000.

Ratcliffe, N.M., 2000, Bedrock geologic map of the Cavendish quadrangle, Windsor County, Vermont: U.S. Geological Survey Geologic Quadrangle Map GQ-1773, scale 1:24,000.

Walsh, G.J. and Aleinikoff, J.N., 1999, U-Pb zircon age of metafelsite from the Pinney Hollow Formation: Implications for the development of the Vermont Appalachians: American Journal of Science , v. 299, p. 157-170.

Ratcliffe, N.M., Harris, A.G., and Walsh, G.J., 1999, Tectonic and regional metamorphic implications of the discovery of Middle Ordovician conodonts in cover rocks east of the Green Mountain massif, Vermont: Canadian Journal of Earth Sciences , v. 36, no. 3, p. 371-382.

Ratcliffe, N.M., and Armstrong, T.R., 1999, Bedrock geologic map of the West Dover and Jacksonville quadrangles, Windham County, Vermont: U.S. Geological Survey Miscellaneous Investigations Series Map I-2552, scale 1:24,000.

Publications:

Map Publications

Surface Gamma-Ray Survey of the Barre West Quadrangle

Walsh, G.J., and Satkoski, A.M., 2005, Surface gamma-ray survey of the Barre West quadrangle, Washington and Orange Counties, Vermont: U.S. Geological Survey Scientific Investigations Report 2005-5276, 19 p

Related links:

USGS-WRD NH-VT District
Vermont Geological Survey
Vermont Agency of Natural Resources