Jack's Crossword Puzzle

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Across
  1. 8. A break or crack in the Earth’s lithosphere along which rocks move
  2. 11. Dense ball of solid material at the center of the Earth.
  3. 12. Theory that pieces of the Earth’s lithosphere are in motion, driven by convection currents in the mantle.
  4. 13. A deep valley where two plates move apart.
  5. 14. The layer of rock that forms the Earth’s outer surface.
  6. 15. A deep canyon on the ocean floor.
  7. 17. The process by which oceanic crust sinks beneath a deep-ocean trench and back into the mantle at a convergent plate boundary.
  8. 19. The undersea mountain chain where new ocean floor is produced; a divergent plate boundary.
  9. 20. German scientist who developed the theory of the continental drift in 1912.
Down
  1. 1. The name of the single landmass that broke apart about 225 million years ago.
  2. 2. A plate boundary where two plates move toward each other.
  3. 3. A layer of molten iron and nickel that surrounds the inner core of the Earth.
  4. 4. A plate boundary where two plates grind against each other, moving in different directions.
  5. 5. A soft layer of the mantle on which the lithosphere floats.
  6. 6. Thickest layer of the Earth; it consists of two layers - the lithosphere and the asthenosphere.
  7. 7. A rigid layer made up of the uppermost part of the mantle and the crust.
  8. 9. The process by which molten material adds new oceanic crust to the ocean floor.
  9. 10. Cause the plates to move; between the lithosphere and the asthenosphere.
  10. 16. A plate boundary where two plates move away from each other.
  11. 18. Alfred Wegener’s hypothesis that the continents were once one huge land mass but have since then drifted apart.