{"thcode":2,"term":{"code":86,"name":"beryllium isotope analysis","parent":654,"scope":"Method of age determination based on measurement of the activity of beryllium-10, used in dating deep-sea sediments, and in determining sedimentation rates."},"uf":[],"bt":[{"code":654,"name":"light stable isotope analysis","parent":609,"scope":"Analytical technique using mass spectrometry to measure the different isotopic forms of low mass (light) elements such as oxygen, hydrogen, carbon, nitrogen and sulfur that occur in samples."},{"code":609,"name":"isotopic analysis","parent":619,"scope":"Experimental determination of the proportion of a given isotope (or isotopes) in a sample."},{"code":619,"name":"laboratory methods","parent":734,"scope":"Techniques to analyze and test samples in a place equipped and designed for the work."},{"code":734,"name":"methods","parent":1,"scope":"Techniques, methods, procedures, or strategies for research, management, collection, or analysis of scientific information in USGS."},{"code":1,"name":"Categories","parent":null,"scope":"Thematic terms for categorizing information resources.  This thesaurus is intended to support finding and understanding scientific information."}],"nt":[],"rt":[]}