{"thcode":4,"term":{"code":"2.1.1.4","name":"Siltstone","parent":"2.1.1","scope":"An indurated silt having the texture and composition of shale but lacking its fine lamination or fissility; a massive mudstone in which silt-sized particles predominate over clay-sized particles."},"uf":[],"bt":[{"code":"2.1.1","name":"Mudstone","parent":"2.1","scope":"A general term that includes claystone, siltstone, shale, and argillite, and that should be used only when the amounts of clay-sized and silt-sized particles are not known or specified, or cannot be precisely identified..."},{"code":"2.1","name":"Clastic rock","parent":"2","scope":"A composed principally of broken fragments that are derived from preexisting rocks or minerals and that have been transported some distance from their place of origin."},{"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":[]}