<descriptor thcode="62"><thesaurus thcode="62" name="Coastal and Marine Ecological Classification Standard" scope="Categories of ecosystems for coastal, estuarine, and marine environments." creator="FGDC" rights="public domain" date="2017-05-10" codetype="alpha" prefix="cmecs" uri="https://www2.usgs.gov/science/CMECS" tblname="cmecs" root_code="root" contact="pschweitzer"><category><term thcode="25" code="16" name="hierarchical" parent="11" scope="Substantive broader-narrower relationships exist among the terms."/><term thcode="25" code="16" name="hierarchical" parent="11" scope="Substantive broader-narrower relationships exist among the terms."/></category><altlabel><altlabel>CMECS</altlabel><altlabel>CMECS</altlabel><altlabel>Coastal and Marine Ecological Classification Standard (CMECS)</altlabel><altlabel>Coastal and Marine Ecological Classification Standard (CMECS)</altlabel></altlabel></thesaurus><term thcode="62" code="SC-279" name="Sand" parent="SC-277" scope="Substrate Group: Geologic Substrate surface layer contains no trace of Gravel and is composed of &gt; 90% Sand (particles 0.0625 millimeters to &lt; 2 millimeters in diameter)."/><bt><term thcode="62" code="SC-277" name="Fine Unconsolidated Substrate" parent="SC-029" scope="Substrate Subclass: Geologic Substrate surface layer contains less than 5% gravel (particles 2 millimeters to &lt; 4,096 millimeters in diameter). ..."/><term thcode="62" code="SC-029" name="Unconsolidated Mineral Substrate" parent="SC-025" scope="Substrate Class: Geologic Substrates with less than 50% cover of Rock Substrate. ..."/><term thcode="62" code="SC-025" name="Geologic Substrate" parent="SC-C003" scope="Substrate Origin: Benthic substrates where percent cover of Rock and Unconsolidated Mineral Substrate exceeds percent cover of both Biogenic and Anthropogenic Substrates, considered separately. ..."/><term thcode="62" code="SC-C003" name="Substrate" parent="root"/><term thcode="62" code="root" name="CMECS" scope="Coastal and Marine Ecological Classification Standard: Category terms encompassing waters from the head of tide or inland incursion of ocean salinity to the splash zone of the coasts to the deepest portions of the oceans and the deep waters of the Great Lakes."/></bt><nt><term thcode="62" code="SC-288" name="Coarse Sand" parent="SC-279" scope="Substrate Subgroup: Geologic Substrate surface layer contains no trace of Gravel and is composed of &gt; 90% Sand, with a median grain size of 0.5 millimeters to &lt; 1 millimeter."/><term thcode="62" code="SC-290" name="Fine Sand" parent="SC-279" scope="Substrate Subgroup: Geologic Substrate surface layer contains no trace of Gravel and is composed of &gt; 90% Sand with a median grain size of 0.125 millimeters to &lt; 0.25 millimeters."/><term thcode="62" code="SC-289" name="Medium Sand" parent="SC-279" scope="Substrate Subgroup: Geologic Substrate surface layer contains no trace of Gravel and is composed of &gt; 90% Sand, with a median grain size of 0.25 millimeters to &lt; 0.5 millimeters."/><term thcode="62" code="SC-287" name="Very Coarse Sand" parent="SC-279" scope="Substrate Subgroup: Geologic Substrate surface layer contains no trace of Gravel and is composed of &gt; 90% Sand, with a median grain size of 1 millimeter to &lt; 2 millimeters."/><term thcode="62" code="SC-291" name="Very Fine Sand" parent="SC-279" scope="Substrate Subgroup: Geologic Substrate surface layer contains no trace of Gravel and is composed of &gt; 90% Sand with a median grain size of 0.0625 millimeters to &lt; 0.125 millimeters."/></nt></descriptor>