ROCK GROUP
DESCRIPTION: Broad classification of geological units based on rock type.
Valid entries:
agglomerate alkali feldspar granite alternating sandstone/mudstone alternating sandstone/siltstone amphibolite andesite argillite ash basalt breccia broken formation cataclasite chert conglomerate dacite diorite dolerite fill gabbro gabbronorite gneiss granite granodiorite granulite gravel greenschist greywacke hornfels ignimbrite limestone loess marble melange metaplutonic metasediment metavolcanic migmatite monzodiorite monzonite mud mudstone mylonite orthogneiss paragneiss peat peridotite pyroxenite quartzite rhyolite sand sandstone schist scoria semischist serpentinite silt siltstone shale syenite tonalite tuff unknownAddition of ? (e.g. ?tonalite) indicates uncertainty of value