Basic Geology/Glossary

This is an incomplete list of geological terminology with brief explanations of each concept.

  • Andesite: Viscous lava erupted from a volcano above a subduction zone.
  • Igneous Rock: A rock produced by the crystallization of magma.
  • Geology: The study of Earth's physical structure and the processes that act on it.
  • Lahar: River of mud, ash, and water.
  • Metamorphic Rock: A rock that has experienced intense temperature and/or pressure after its formation and has changed its composition and/or texture.
  • Mineral: A naturally occurring solid inorganic substance with a distinct crystal structure.
  • Pahoehoe: Lava with an undulating surface, may have a ropey appearance.
  • Rift Valley: A gap between the continental crust marked by volcanism; rift valleys may eventually develop into oceans, seas, etc.
  • Rock: A natural material composed of minerals.
  • Sedimentary Rock: A rock that has been formed by the lithification of sediment but has not been metamorphosed.
  • Subduction zone: Area where plates meet, and one slides beneath the other.
  • Texture: The physical appearance of a rock.