{"thcode":61,"term":{"code":504,"name":"radiometric dating","parent":502,"scope":"used for all absolute dating techniques based on analyzing the abundance of a radioactive isotope and its decay products in a given geologic (or archaeologic) sample."},"uf":[],"bt":[{"code":502,"name":"absolute dating (geologic)","parent":501,"scope":"used for all geologic dating methods yielding numerical ages"},{"code":501,"name":"geologic dating","parent":486,"scope":"used for all methods of dating geologic (or archaeologic) materials, including both absolute dating methods (yielding numerical ages) relative dating methods (for determining the relative order of geologic events)."},{"code":486,"name":"laboratory methods","parent":398,"scope":"used for all laboratory procedures in support of scientific investigations."},{"code":398,"name":"research method","parent":1,"scope":null},{"code":1,"name":"Marine Realms Information Bank (MRIB) keyword categories","parent":null,"scope":null}],"nt":[{"code":505,"name":"beryllium-7 dating","parent":504,"scope":"absolute dating technique based on the decay of beryllium-7 to lithium-7; a short-range method for dating sediment samples."},{"code":506,"name":"carbon-14 dating","parent":504,"scope":"absolute dating technique based on the decay of carbon-14 to nitrogen-14; a short-range method for dating organic samples."},{"code":507,"name":"cesium-137 dating","parent":504,"scope":"absolute dating technique based on the decay of cesium-137 to barium-137; a short-range method for dating sediment samples that postdate atmospheric nuclear testing."},{"code":509,"name":"potassium-argon dating","parent":504,"scope":"absolute dating technique based on the decay of potassium-40 to argon-40; a long-range method for dating rock samples."},{"code":510,"name":"tritium-helium dating","parent":504,"scope":"absolute dating technique based on the decay of tritium (hydrogen-3) to helium-3; a short-range method for dating water samples."},{"code":508,"name":"uranium-series dating","parent":504,"scope":"a family of absolute dating techniques based on the decay of uranium isotopes through a series of steps to stable end products; includes long-range methods for dating rock samples (uranium-lead dating) and short-range methods for dating sediment samples (uranium-thorium dating and lead-210 dating)."}],"rt":[]}