<descriptor thcode="2"><thesaurus thcode="2" name="USGS Thesaurus" scope="Topics and methods of scientific study carried out by USGS, with product types, scientific disciplines, geologic time, and types of institutional structure and activities.  Broad and shallow, used to help people find scientific information." creator="U.S. Geological Survey" rights="Public domain" edition="2.0" date="2020-01-09" codetype="number" prefix="topic" uri="https://www2.usgs.gov/science/USGSThesaurus" tblname="term" nonpref="nonpref" relterm="relterm" root_code="1" contact="pschweitzer"><category><term thcode="25" code="29" name="distinct labels" parent="26" scope="Preferred labels (descriptor texts) are distinct within the thesaurus. A concept can be specified either by its unique identifier (code) or by the text of its descriptor."/><term thcode="25" code="16" name="hierarchical" parent="11" scope="Substantive broader-narrower relationships exist among the terms."/><term thcode="25" code="13" name="transitive" parent="12" scope="Narrower terms have an &quot;is a&quot; relationship with their broader terms, and generally can be described as part-of, type-of, or instance-of the broader term."/><term thcode="25" code="21" name="disciplines" parent="2" scope="Broad categories of human inquiry or activity, such as scientific disciplines."/><term thcode="25" code="20" name="methods" parent="2" scope="Actions taken to obtain or analyze information"/><term thcode="25" code="19" name="organizational functions" parent="2" scope="Things that organizations do, typically including various types of programs, projects, and services."/><term thcode="25" code="7" name="temporal" parent="2" scope="Terms indicate periods of time, such as chronostratigraphic units, named historical periods or intervals surrounding known historical events, or seasons."/><term thcode="25" code="5" name="theme" parent="2" scope="Terms indicate domains of human concern, such as scientific discipline, societal problems, or characteristics of earth, space, oceans, and living things."/><term thcode="25" code="29" name="distinct labels" parent="26" scope="Preferred labels (descriptor texts) are distinct within the thesaurus. A concept can be specified either by its unique identifier (code) or by the text of its descriptor."/><term thcode="25" code="16" name="hierarchical" parent="11" scope="Substantive broader-narrower relationships exist among the terms."/><term thcode="25" code="13" name="transitive" parent="12" scope="Narrower terms have an &quot;is a&quot; relationship with their broader terms, and generally can be described as part-of, type-of, or instance-of the broader term."/><term thcode="25" code="21" name="disciplines" parent="2" scope="Broad categories of human inquiry or activity, such as scientific disciplines."/><term thcode="25" code="20" name="methods" parent="2" scope="Actions taken to obtain or analyze information"/><term thcode="25" code="19" name="organizational functions" parent="2" scope="Things that organizations do, typically including various types of programs, projects, and services."/><term thcode="25" code="7" name="temporal" parent="2" scope="Terms indicate periods of time, such as chronostratigraphic units, named historical periods or intervals surrounding known historical events, or seasons."/><term thcode="25" code="5" name="theme" parent="2" scope="Terms indicate domains of human concern, such as scientific discipline, societal problems, or characteristics of earth, space, oceans, and living things."/></category><altlabel><altlabel>USGSThesaurus</altlabel><altlabel>USGSThesaurus</altlabel></altlabel></thesaurus><term thcode="2" code="2297" name="assessment units" parent="2093" scope="Geographic areas for which a valuable resource is estimated.  Frequently defined in two or more dimensions, for example specifying underground formations in a given geographic area.  Functions or services may be estimated in addition to material resources."/><uf><usefor name="permissive tracts"/></uf><bt><term thcode="2" code="2093" name="study areas" parent="474" scope="Geospatial data describing the areas from which samples were taken or observations were made, typically polygonal.  May be approximate, as in bounding coordinates, or precise."/><term thcode="2" code="474" name="geospatial datasets" parent="235" scope="Collections of related digital information that are geographically referenced."/><term thcode="2" code="235" name="datasets" parent="808" scope="Digital information in a format suitable for direct input to software that can analyze its meaning in the scientific, engineering, or business context for which the data were collected."/><term thcode="2" code="808" name="product types" parent="1" scope="General representation of the information in a resource, such as a map or data set."/><term thcode="2" code="1" name="Categories" scope="Thematic terms for categorizing information resources.  This thesaurus is intended to support finding and understanding scientific information."/></bt><rt><term thcode="2" code="2294" name="carbon dioxide storage assessment" parent="773" scope="Estimates of the storage capacity of carbon dioxide in geologic units at depths of 3,000 to 13,000 feet that are capable of maintaining carbon dioxide in a supercritical state."/><term thcode="2" code="799" name="energy resources" parent="777" scope="Natural resources that are used for heat and power generation, including oil, natural gas, coal, and geothermal energy."/><term thcode="2" code="745" name="mineral resources" parent="777" scope="Natural occurrences of useful inorganic elements or compounds."/><term thcode="2" code="773" name="natural resource assessment" parent="776" scope="Estimation of the actual or potential value of natural materials and processes."/></rt></descriptor>