Naturally Occuring in Rock, Soil and Water
in the Champlain Valley have been documented in primary sedimentary layers, plus as secondary coatings along fractures (McKeown, 1951 and Whitten, 1988). Bedrock mapping in the Colchester quadrangle (Kim and Thompson, 2002) focused in an area where domestic wells exceeded gross alpha standards. Detailed mapping, structural analysis, and geochemistry provided broad-based understanding of the radionuclide problem and serves as a prototype for future analysis throughout the State of Vermont.
A statewide compilation of radioactivity data (below) was completed by Kim (2002) and other references are listed at the bottom of this page.
Compilation and Assessment of
Geophysical and Geological Radioactivity Data in Vermont:
The map is a compilation of areas where ground-based
and airborne geophysical and geological surveys have indicated the presence
of elevated naturally occurring radioactivity relative to surrounding
areas. Public water supplies with gross alpha radioactivity equal to
or greater than 15 picocuries/liter and uranium occurrences are also
shown. Elevated radioactivity areas determined via these surveys in
the Milton and Colchester area coincide with many of the locations of
domestic groundwater wells with elevated radioactivity. Therefore, the
Vermont Geological Survey is showing the statewide distribution of elevated
radioactivity areas in Vermont based on an assessment and compilation
of data from older sources.
Radioactivity Map Fact Sheet
Alpha Radiation Fact Sheet
of Health Fact Sheet
Map of Elevated Radioactivity Relative to Surrounding Areas
To view images, please click in the boxes below. Two
images are given for each plate - small and larger .jpg files. The readme
files for each plate include information on data sources and production
of the digital data.
To order paper maps (11.5"x17") or to obtain digital
data (jpg and Arcinfo), please contact the
Vermont Geological Survey, 1 National Life Dr., Davis 2, Montpelier, VT 05602-3920. Please reference: Kim, Jonathan, Compiler,
2002, Compilation and Assessment of Radioactivity Data in Vermont: Vermont
Geological Survey General Interest Publication.
Radionuclides, Groundwater Chemistry, and Hydrogeology Above, Below, and Through the Hinesburg Thrust: Kim, et al, 2009,GSA Abstracts with Programs, v. 41, #3.
Radionuclide-enriched groundwater, Knox Mountain pluton, Vermont: occurrence and lithologic controls: Gleason et al, 2007,GSA Abstracts with Programs, v. 39 #1, p. 102.
Lithologic control on naturally occurring radioactivity and ground water chemistry across the Richardson Memorial Contact, central VT: Kim, et al, 2005, GSA Abs. with Prog., v. 37 #1.
Evaluation of Geologic Controls on Elevated Naturally-Occurring Radioactivity in Bedrock Ground Water Wells, NW Vermont: North, et al, 2005, GSA Abs with Prog, v. 37 #1, p. 78.
Walsh, G.J. and Satkoski, A.M., 2005, Surface gamma-ray survey of the Barre West quadrangle, Washington and Orange Counites, Vermont:
USGS Scientific Investigations Report 2005-5276, 19 p., only available on-line at http://pubs.usgs.gov/sir/2005/5276/
Bedrock and Radionuclide Mapping in the Colchester Quadrangle, Vermont: Kim and Thompson, 2002, GSA Abstracts with Programs, v. 34 #1, p. A17. Also see Plate 3 of the Colchester Open File report (VG01-1)
Geologic Context of Elevated Radionuclide Occurrences in NW Vermont: Kim & Becker, 2001, GSA Abstracts with Programs, v. 33, #1, p. A60.