{"thcode":4,"term":{"code":"5.2.2","name":"Slate","parent":"5.2","scope":"A compact, fine-grained metamorphic rock that possesses slaty cleavage and hence can be split into slabs and thin plates"},"uf":[],"bt":[{"code":"5.2","name":"Metasedimentary rock","parent":"5","scope":"A sedimentary rock that shows evidence of having been subjected to metamorphism."},{"code":"5","name":"Metamorphic rock","parent":"0","scope":"A rock derived from pre-existing rocks by mineralogical, chemical, and\/or structural changes, essentially in the solid state, in response to marked changes in temperature, pressure, shearing stress, and chemical environment, generally at depth in the earth's crust."},{"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":[]}