{"thcode":2,"term":{"code":1804,"name":"petroleum","parent":1005,"scope":"Naturally occurring hydrocarbons, typically fluid or gas, often of economic use.  Includes oil, natural gas, and asphaltic compounds found in tar sands and oil shales."},"uf":[{"name":"oil spills","usewith":{"code":1723,"name":"industrial pollution","parent":769,"scope":"Introduction of harmful substances into the environment by manufacturing, power generation, mining, or material processing."}}],"bt":[{"code":1005,"name":"rocks and deposits","parent":287,"scope":"Solid masses that make up the earth's crust as well as accumulations of materials. Use for major rock types and unconsolidated deposits. For deposits of economic value, see related terms."},{"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":[],"rt":[{"code":770,"name":"natural gas resources","parent":799,"scope":"Stocks of naturally formed hydrocarbon gases which are usually associated with petroleum fields.  Useful for heating, they are principally methane, but can be ethane, butane, or propane."},{"code":829,"name":"oil resources","parent":799,"scope":"Deposits (pools) of highly valuable liquid hydrocarbons or fossil fuels."}]}