{"thcode":2,"term":{"code":1037,"name":"sedimentology","parent":464,"scope":"Branch of earth sciences concerned with the study of the origin, composition, transport, and changes of materials deposited by water, wind, or ice."},"uf":[],"bt":[{"code":464,"name":"geology","parent":291,"scope":"Study of the planet earth, its composition, structure, physical and chemical processes, and history since its origin."},{"code":291,"name":"earth sciences","parent":1019,"scope":"Broad term for all science related to the study of the earth."},{"code":1019,"name":"sciences","parent":1,"scope":"Major educational fields, fields of study, and professional groupings within 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":[{"code":83,"name":"bedforms","parent":1035,"scope":"Fluctuations from horizontal layers in sediments or sedimentary rocks made by flow on the beds of alluvial channels."},{"code":132,"name":"building stone resources","parent":798,"scope":"Deposits of rocks used in construction, including crushed stone and dimension stone. Dimension stone includes limestone and granite, quarried in large blocks, and shaped in cubes, panels and other forms."},{"code":164,"name":"clay deposits","parent":1199,"scope":"Fine-grained sedimentary soil deposits, containing hydrated silicas of aluminum, that are plastic and sticky when wet and harden when heated."},{"code":248,"name":"diagenesis","parent":451,"scope":"Chemical, physical, and biological changes in sediment during and after its conversion to rock (lithification)."},{"code":353,"name":"erosion","parent":451,"scope":"The process whereby materials of the earth's crust are loosened, dissolved, or worn away and simultaneously moved from one place to another."},{"code":493,"name":"grain-size analysis","parent":619,"scope":"Method of studying soils, sediments, sands, or rock by determining the size, distribution, and proportion of selected particles."},{"code":500,"name":"gravel deposits","parent":1199,"scope":"Alluvial accumulations of small unconsolidated rock fragments, such as pebbles and cobbles, used in construction as fill, ground cover, or aggregate for concrete."},{"code":1011,"name":"sand deposits","parent":1199,"scope":"Deposits of loose particles of rock or mineral (sediment) that range in size from 0.0625-2.0 millimeters in diameter."},{"code":1034,"name":"sediment transport","parent":451,"scope":"Transport of solid particles of unconsolidated rock and mineral fragments, chemical precipitates, or biological materials."},{"code":1035,"name":"sedimentary rocks","parent":1005,"scope":"Rocks formed by the consolidation of loose, uncemented pieces of sediments."},{"code":1036,"name":"sedimentation","parent":451,"scope":"Process of deposition of sediments (loose, uncemented pieces of rock, mineral fragments, or biological materials).  The sediments settle out of water or air into layers on a surface."},{"code":1062,"name":"sieve-size analysis","parent":493,"scope":"Analytic technique determining the distribution of the different sizes of particles in soil, sediment, or rock samples by measuring the percentage that will pass through mesh holes of known size."},{"code":1189,"name":"trenching","parent":379,"scope":"Field method used by earth scientists to study the underground structure of an area. A long narrow ditch is dug to locate geologic features, such as a fault."}]}