<descriptor thcode="3"><thesaurus thcode="3" name="Alexandria Digital Library Feature Type Thesaurus" scope="Types of named geographic features.  Applicable also to many unnamed features but reflects the level of detail traditionally shown on maps, so some feature types specified in scientific studies may not be well represented here.  Not highly specific." creator="Alexandria Digital Library Project, University of California at Santa Barbara" rights="Copyright (c) 1999-2004 by the Regents of the University of California. All rights reserved.\r\n\r\nRedistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met:\r\n\r\n   1. Redistributions of source code or dataset must retain the above copyright notice, this list of conditions and the following disclaimer.\r\n   2. Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following disclaimer in the documentation and/or other materials provided with the distribution.\r\n   3. Neither the name of the University of California, Santa Barbara nor the names of its contributors may be used to endorse or promote products derived from this software or dataset without specific prior written permission.\r\n\r\nTHIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS &quot;AS IS&quot; AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDERS AND CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE OR DATASET, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.\r\n\r\n[This statement is derived from the BSD license template, http://www.opensource.org/licenses/bsd-license.php]" edition="2.0" date="2002-07-03" codetype="number" prefix="feature" uri="http://www.usgs.gov/science/ADLFeatureType" tblname="feature" nonpref="featnp" relterm="featrt" root_code="1" contact="pschweitzer"><category><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="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="16" name="hierarchical" parent="11" scope="Substantive broader-narrower relationships exist among the terms."/><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="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="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="16" name="hierarchical" parent="11" scope="Substantive broader-narrower relationships exist among the terms."/><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."/></category><altlabel><altlabel>ADLFTT</altlabel><altlabel>ADLFTT</altlabel><altlabel>ADLFeatureType</altlabel><altlabel>ADLFeatureType</altlabel></altlabel></thesaurus><term thcode="3" code="816" name="physiographic features" parent="1"/><uf><usefor name="aprons (geological)"/><usefor name="blowholes"/><usefor name="blowouts"/><usefor name="boulder fields"/><usefor name="cones (geological)"/><usefor name="crevasses"/><usefor name="fissures"/><usefor name="furrows"/><usefor name="geological features"/><usefor name="grades (physiographic)"/><usefor name="hammocks"/><usefor name="inclines"/><usefor name="landslides"/><usefor name="meander necks"/><usefor name="pitches (physiographic)"/><usefor name="polders"/><usefor name="potholes"/><usefor name="rockfalls"/><usefor name="sinkholes"/><usefor name="sinks"/><usefor name="siphon (physiographic)"/><usefor name="slides (natural)"/><usefor name="slopes"/><usefor name="talus slopes"/><usefor name="terraces (physiographic)"/><usefor name="uplands"/></uf><bt><term thcode="3" code="1" name="Categories"/></bt><nt><term thcode="3" code="28" name="alluvial fans" parent="816" scope="Fan-shaped deposits of alluvium (river or stream-bed  sediment)."/><term thcode="3" code="62" name="arroyos" parent="816" scope="Small deep flat-floored channels or gullies of an ephemeral stream or of an intermittent stream, usually with vertical or steeply cut banks. [Adapted from Glossary of Geology, 4th ed.]"/><term thcode="3" code="77" name="badlands" parent="816" scope="Areas characterized by a maze of very closely spaced, deep, narrow, steep-sided ravines, and sharp crests and pinnacles. [NIMA GEONet Designation ... Definitions &lt;http://164.214.2.59/gns/html/desig.html&gt; ]"/><term thcode="3" code="84" name="banks (hydrographic)" parent="816" scope="Sloping margins of, or the ground bordering, a stream, and serving to confine the water to the natural channel during the normal course of flow. [Glossary of Geology, 4th ed.]"/><term thcode="3" code="92" name="bars (physiographic)" parent="816" scope="Natural accumulations of sand, gravel, or other material forming an underwater or exposed embankment. [USGS Circ 1048]"/><term thcode="3" code="95" name="basins" parent="816" scope="Bowl-shaped, natural depressions in the surface of the land or ocean floor. [Adapted from USGS Circ 1048]"/><term thcode="3" code="102" name="beaches" parent="816" scope="Sloping shores along a body of water that is washed by waves or tides and is usually covered by sand or gravel. [USGS GNIS Feature Class Definitions &lt;http://geonames.usgs.gov/domestic/feature_class.htm&gt;]"/><term thcode="3" code="111" name="bights" parent="816" scope="Long gradual bends or gentle curves, or slight crescent-shaped indentations, in the shoreline of an open coast or of a bay. [Glossary of Geology, 4th ed.]"/><term thcode="3" code="168" name="capes" parent="816" scope="Projection of land extending into a body of water that prominently marks a change in or interrupts the coastal trend of that water body. [USGS Circ 1048]"/><term thcode="3" code="183" name="caves" parent="816" scope="Natural underground passageways or chambers, or hollowed out cavities in the side of a cliff. [USGS GNIS Feature Class Definitions &lt;http://geonames.usgs.gov/domestic/feature_class.htm&gt;]"/><term thcode="3" code="200" name="cirques" parent="816" scope="Bowl-like hollows partially surrounded by cliffs or steep slopes at the head of a glaciated valley. [NIMA GEONet Designation ... Definitions &lt;http://164.214.2.59/gns/html/desig.html&gt;]"/><term thcode="3" code="211" name="cliffs" parent="816" scope="High vertical, near-vertical, or overhanging faces of rock, earth, or ice. [USGS Circ. 1048]"/><term thcode="3" code="285" name="craters" parent="816" scope="Circular-shaped depressions at the summit of a volcanic core or on the surface of the land caused by the impact of a meteorite; man-made depressions caused by an explosion. [USGS GNIS Feature Class Definitions &lt;http://geonames.usgs.gov/domestic/feature_class.htm&gt;]"/><term thcode="3" code="305" name="deltas" parent="816" scope="Flat plains formed by alluvial deposits at the mouth of a stream. [NIMA GEONet Designation ... Definitions &lt;http://164.214.2.59/gns/html/desig.html&gt;]"/><term thcode="3" code="342" name="dunes" parent="816" scope="Low mounds, ridges, banks, or hills of loose, wind-blown granular material, either bare or covered with vegetation, capable of movement from place to place but always retaining their characteristic shape. [Adapted from Glossary of Geology, 4th ed.]"/><term thcode="3" code="399" name="flats" parent="816" scope="Relatively level areas within regions of greater relief. [USGS GNIS Feature Class Definitions &lt;http://geonames.usgs.gov/domestic/feature_class.htm&gt;]"/><term thcode="3" code="433" name="gaps" parent="816" scope="Ravines or gorges cut deeply through mountain ridges, or between hills or mountains. [Glossary of Geology, 4th ed.]"/><term thcode="3" code="578" name="isthmuses" parent="816" scope="Narrow sections of land in a body of water connecting two larger land areas. [USGS Feature Class Definitions &lt;http://geonames.usgs.gov/domestic/feature_class.htm&gt;]"/><term thcode="3" code="584" name="karst areas" parent="816" scope="Areas of geologic formations of irregular limestone deposits with sinks, underground streams, and caverns.  [EPA Terms of Environment &lt; http://www.epa.gov/OCEPAterms/&gt;]"/><term thcode="3" code="614" name="ledges" parent="816" scope="Narrow shelves or projections of rock formed on a rock wall or cliff face. [Glossary of Geology, 4th ed.]"/><term thcode="3" code="658" name="massifs" parent="816" scope="Massive topographic and structural features, commonly formed of rocks more rigid than those of their surroundings. [Adapted from Glossary of Geology, 4th ed.]"/><term thcode="3" code="668" name="mesas" parent="816" scope="Very broad, flat-topped, usually isolated hills or mountains of moderate height bounded on at least one side by a steep cliff or slope and representing an erosion remnant. [Glossary of Geology, 4th ed.]"/><term thcode="3" code="686" name="mineral deposit areas" parent="816" scope="Areas where masses of naturally occurring mineral material are found, e.g. metal ores or nonmetallic minerals. [Adapted from Glossary of Geology, 4th ed.]"/><term thcode="3" code="703" name="moraines" parent="816" scope="Accumulations of earth and stones carried and deposited by a glacier. [USGS Circ 1048]"/><term thcode="3" code="710" name="mountains" parent="816" scope="Landmasses that project conspicuously above their surroundings. [USGS Circ 1048]"/><term thcode="3" code="732" name="natural rock formations" parent="816" scope="Naturally formed topographic features, commonly differing conspicuously from adjacent objects or material. [Adapted from Glossary of Geology, 4th ed.]"/><term thcode="3" code="827" name="plains" parent="816" scope="Regions of general uniform slope, comparatively level and of considerable extent. [USGS Circ 1048]"/><term thcode="3" code="832" name="plateaus" parent="816" scope="Comparatively flat areas of great extent and elevation; specif. extensive land regions considerably above the adjacent country or above sea level; commonly limited on at least one side by an abrupt descent, have flat or nearly smooth surfaces but are often dissected by deep valleys and surmounted by high hills or mountains, and have a large part of their total surface at or near the summit level. [Glossary of Geology, 4th ed.]"/><term thcode="3" code="835" name="playas" parent="816" scope="Closed depressions in an arid or semi-arid region that are periodically inundated by surface runoff, or the salt flat within such a closed basin.[Encyc. Dictionary of Physical Geography]"/><term thcode="3" code="921" name="reefs" parent="816" scope="Chains of rocks or coral at or near the surface of water. [USGS Circ 1048]"/><term thcode="3" code="1010" name="seafloor features" parent="816"/><term thcode="3" code="1135" name="tectonic features" parent="816" scope="Features resulting from structural deformation of the earth's crust through tectonic processes. [Adapted from American Heritage Dic. of the English Language, 4th ed.]"/><term thcode="3" code="1197" name="valleys" parent="816" scope="Low-lying land bordered by higher ground; especially elongate, relatively large gently sloping depressions of the Earth's surface, commonly situated between two mountains or between ranges of hills or mountains, and often containing a stream with an outlet. [Glossary of Geology, 4th ed.]"/><term thcode="3" code="1208" name="volcanic features" parent="816" scope="Features formed from those igneous rocks that have reached or nearly reached the Earth's surface before solidifying. [Adapted from Glossary of Geology, 4th ed.]"/></nt><rt><term thcode="3" code="112" name="biogeographic regions" parent="928" scope="Geographic regions characterized chiefly by the dominant forms of plant life and the prevailing climate. [Adapted from American Heritage Dic. of the English Language, 4th ed.]"/></rt></descriptor>