Explanation of how geologists date rocks (to determine the ages of the Earth, fossils, mineral deposits, and other geologic events) and processes using radiometric dating techniques based on radioactive isotopes of carbon and potassium/argon.
The area contributing recharge to this aquifer is undergoing rapid growth, generating more wastewater. We found that nitrate, a major component of wastewater and a nutrient that can degrade water quality, has increased in the creeks in this area.
Site on the Chlorofluorocarbon Laboratory and its analytical services for CFCs, sulfur hexafluoride, dissolved gases including nitrogen, argon, methane, carbon dioxide, oxygen, and helium, and tritium/helium-3 dating.
Instrument measures elemental abundance and isotopic ratios in samples as small as a few nanograms. Uses include geochronology, geological thermometry, and trace element geochemistry of geological and biological materials.
USGS operates a low-enriched uranium-fueled, pool-type reactor located at the Denver Federal Center. We use it for analyses of fissile and fissionable isotopes, geochemical analysis, and geochronology.