Originator: Robert P. Kucks
Terrestrial Radioactivity and Gamma-ray Exposure in the
United States and Canada: Gridded geographic images
Originator: Duval, Joseph S.
Originator: Carson, John M.
Originator: Holman, Peter B.
Originator: Darnley, Arthur G.
Terrestrial radioactivity and gamma-ray exposure in the United States and Canada
Series_Name: U.S. Geological Survey Open-File Report
Aerial gamma-ray surveys measure the gamma-ray flux produced
by the radioactive decay of the naturally occurring elements
K-40, U-238, and Th-232 in the top few centimeters of rock or
soil. If the gamma-ray system is properly calibrated the data
can be expressed in terms of the estimated concentrations of
the radioactive elements. A ternary color-composite image was
generated by commercial software Geosoft Oasismontaj to map the
combination of all three elements.
During the period 1975-83, the U.S. Department of Energy carried
out the National Uranium Resource Evaluation (NURE) Program,
which included aerial gamma-ray surveys of most of the United
States. These data were reprocessed to generate this product.
Digital Data Series DDS-9 (CD-ROM) contains gridded radiometric geophysical
data images that were created for the Decade of North American
Geology (DNAG) but only available for the U.S.
Because uranium, thorium, and potassium concentration data are
useful in geologic studies and because the NURE data are the only
nationwide database on the natural radiation environment, the
U.S. Geological Survey reprocessed the aerial gamma-ray data
to produce maps showing surface concentrations of potassium,
uranium, and thorium for the conterminous United States.
Currentness_Reference: all available NURE data for the U.S. has been processed
Maintenance_and_Update_Frequency: None planned
Contact_Person: Robert P. Kucks
Contact_Organization: U.S. Geological Survey
Address_Type: mailing address
Contact_Voice_Telephone: (303) 236-1405
Box 25046, MS 964
Denver Federal Center
The U.S Geological Survey reprocessed the aerial gamma-ray (NURE)
data to produce maps showing surface concentrations of potassium,
uranium, and thorium for the conterminous United States. These
maps have been released as USGS Open-File Reports. Some of the
reprocessed data have also been released in profile form. The
Canadian Geological Survey data were processed by the Radiation
Geophysics Section of the CGS. See Open-File Report 2005-1413 for
USGS employees: Duval, Riggle, and Snyder
Canadian GS employees: Carson, Holman, and Darnley
The NURE data were originaly stored in ASCII format on 9-track
magnetic tapes. They are currently available on the report DVD
as Geosoft Oasismontaj databases (.gdb) but can be converted to
Theme_Keyword: ternary, gamma-ray, radiometric
Theme_Keyword_Thesaurus: ISO 19115 Topic Category
Place_Keyword: United States, Canada