<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="745" name="mineral resources" parent="777" scope="Natural occurrences of useful inorganic elements or compounds."/><bt><term thcode="2" code="777" name="natural resources" parent="1174" scope="Stocks of anything naturally occurring that have a beneficial use for man including economic, nutritional, recreational, aesthetic, and other benefits."/><term thcode="2" code="1174" name="topics" parent="1" scope="Themes, subjects, and concerns for which USGS information resources are relevant."/><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><nt><term thcode="2" code="2094" name="critical minerals" parent="745" scope="A non-fuel mineral or mineral material essential to the economic and national security of the US, the supply chain of which is vulnerable to disruption, and that serves an essential function in the manufacturing of a product, the absence of which would have significant consequences for our economy or our national security."/><term thcode="2" code="724" name="metallic mineral resources" parent="745" scope="Resources from which ductile, malleable, opaque,and reflective metals that are also good heat and electricity conductors can be extracted."/><term thcode="2" code="798" name="nonmetallic mineral resources" parent="745" scope="Useful mineral deposits that are not metals.  Includes materials used for construction, decoration, fuel, and industrial purposes."/></nt><rt><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."/><term thcode="2" code="312" name="economic geology" parent="464" scope="Scientific study of the formation, location, and use of marketable geologic materials including fuels, metals, minerals, and water."/><term thcode="2" code="2043" name="mineral deposits" parent="1005" scope="Deposits in which particular minerals are concentrated, typically noticed and studied if the minerals have economic value."/><term thcode="2" code="747" name="mineralogy" parent="464" scope="Branch of earth sciences concerned with the study of naturally occurring inorganic elements or compounds."/><term thcode="2" code="1703" name="ore formation" parent="435" scope="Geochemical processes resulting in concentration of useful chemical elements and compounds, in earth materials.  Typically refers to metal ores."/></rt></descriptor>