Geologic Time

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Across
  1. 3. a rupture in the crust of a planetary-mass object, such as Earth, that allows hot lava, volcanic ash, and gases to escape from a magma chamber below the surface.
  2. 5. a type of excavation or depression in the ground that is generally deeper than it is wide.
  3. 7. the relatively thin part of the earth's crust which underlies the ocean basins. It is geologically young compared with the continental crust and consists of basaltic rock overlain by sediments.
  4. 9. a fracture or zone of fractures between two blocks of rock.
Down
  1. 1. a scientific theory that explains how major landforms are created as a result of Earth's subterranean movements.
  2. 2. the molten or semi-molten natural material from which all igneous rocks are formed.
  3. 4. the outermost layer of Earth's lithosphere that makes up the planet's continents and continental shelves and is formed near subduction zones at plate boundaries.
  4. 6. the formation of new areas of oceanic crust, which occurs through the upwelling of magma at midocean ridges and its subsequent outward movement on either side.
  5. 8. an elevated portion of the Earth's crust, generally with steep sides that show significant exposed bedrock.