{"thcode":4,"term":{"code":"2.6.4","name":"Iron formation","parent":"2.6","scope":"A chemical sedimentary rock, typically thin-bedded and\/or finely laminated, containing at least 15% iron of sedimentary origin, and commonly but not necessarily containing layers of chert"},"uf":[],"bt":[{"code":"2.6","name":"Chemical sedimentary rock","parent":"2","scope":"A sedimentary rock composed primarily of material formed directly by precipitation from solution or colloidal suspension or by the deposition of insoluble precipitates."},{"code":"2","name":"Sedimentary rock","parent":"0","scope":"A rock resulting from the consolidation of loose sediment that has accumulated in layers..."},{"code":"0","name":"Earth material","parent":null,"scope":"Geologic map unit classification (Bruce R. Johnson) version 6.2: A hierarchical classification of earth materials for digital geologic maps."}],"nt":[],"rt":[]}