Constructed farm ponds represent significant breeding, rearing, and overwintering habitat for amphibians in the Driftless Area Ecoregion of Minnesota, Wisconsin, and Iowa. Links to fact sheet, brochure, annual reports, field manual, and final report.
Brief review of some of the fundamentals of stable isotope geochemistry including definitions, basic principles, standards, and guidelines on reporting data.
Describes the value of molecular biology genetic tools in enhancing the delineation of the genetic diversity and the effects of environmental degradation on living species. Links to research, which differentiated two species of sage-grouse.
Site to obtain currently available geochemical reference materials, certificates for reference materials no longer available, reference materials in production, and order and processing information. Some documents in PDF format.
Manual of chemical sediment analysis using Coulometer and CHN Analyzers to measure carbon content, spectrometric analysis for biogenic silica, and radiochemistry to measure isotopes. Includes techniques,sample preparation, and safety procedures.
Overview of chemical analyses, tracer studies, gas geochemistry, stable isotopes analyses, organic chemistry, and thermometry capabilities at major USGS laboratories with links to technique, equipment, and contacts for each procedure.
Description of the methods of geochronology used to estimate the dating of rocks and sediments with links to technique, equipment and contacts for a variety of methods.
Booklet giving general explanations of geologic time, major divisions of geologic time, relative and radiometric time scales, index fossils, and the age of the earth.
Services available at the Geological Survey TRIGA Reactor (GSTR) site in Denver with information on irradiation, neutron activation analysis, fission track radiography, and geochronology and tours of the facility.
U.S. Department of the Interior |
U.S. Geological Survey