{"thcode":2,"term":{"code":455,"name":"geologic history","parent":287,"scope":"Record (and inferred reconstruction) of the origin and development of the earth since its formation."},"uf":[{"name":"chronostratigraphy","usewith":false},{"name":"geohistory","usewith":false}],"bt":[{"code":287,"name":"earth characteristics","parent":1174,"scope":"The measurable, definable properties and features of the earth."},{"code":1174,"name":"topics","parent":1,"scope":"Themes, subjects, and concerns for which USGS information resources are relevant."},{"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":[{"code":288,"name":"earth history","parent":455,"scope":"The structural and compositional changes that the earth has undergone from its formation. Use for discussions of the whole earth (or large sections of it) instead of regional studies."}],"rt":[{"code":115,"name":"biostratigraphy","parent":1104,"scope":"Branch of geology concerned with the separation and differentiation of rock units based on the fossils they contain."},{"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":668,"name":"lithostratigraphy","parent":1104,"scope":"Branch of stratigraphy dealing with the study of units of rock. Each unit is composed of a body of rock which is dominated by a certain lithology or similar color, mineralogic composition, and grain size."},{"code":861,"name":"paleontology","parent":291,"scope":"Study of life in past geologic time based on fossil plants and animals."},{"code":862,"name":"paleoseismology","parent":1050,"scope":"Branch of seismology concerned with ancient earthquakes.  Clues which indicate seismic activities in the geologic past are used  to date and determine the effects of those earthquakes."},{"code":1104,"name":"stratigraphy","parent":464,"scope":"Branch of geology concerned with the study of the formation, composition, ordering in time, and arrangement in space of stratified rocks."}]}