Vocabulary - Plate Tectonics - Part 1

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Across
  1. 3. The arrangement of the natural and artificial physical features of an area.
  2. 4. Contain characteristic pillow-shaped structures that are attributed to the extrusion of the lava underwater, or subaqueous extrusion.
  3. 5. The rigid outer part of the earth, consisting of the crust and upper mantle.
  4. 9. Relating to or denoting the depths or bed of the ocean, especially between about 10,000 and 20,000 feet (3,000 and 6,000 m) down.
  5. 11. The widest layer of the Earth, and it lies between the thin outer layer, the crust, and the super-heated outer core. It’s made of a semi-molten rock called magma.
  6. 13. A device for determining the depth of the seabed or detecting objects in water by measuring the time taken for sound echoes to return to the listener.
  7. 15. Extremely hot liquid and semi-liquid rock located under Earth's surface. When it flows onto Earth's surface, it is called lava.
  8. 17. A supercontinent that formed during the late Neoproterozoic and began to break up, involving the separation of Antarctica from South America and Australia.
  9. 19. The relatively thick part of the earth's crust that forms the large landmasses. It is generally older and more complex than the oceanic crust.
  10. 21. A massive, irregularly shaped slab of solid rock, generally composed of both continental and oceanic lithosphere.
  11. 22. The hypothetical landmass that existed when all continents were joined, from about 300 to 200 million years ago.
  12. 23. Great flat sediment-covered areas of ocean floor.
  13. 24. 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.
  14. 25. Typically form along the mid-ocean ridges, such as the East Pacific Rise and the Mid-Atlantic Ridge. These are locations where two tectonic plates are diverging, and new crust is being formed.
Down
  1. 1. The hypothesis that the Earth's continents have moved over geologic time relative to each other, thus appearing to have "drifted" across the ocean bed.
  2. 2. The ancient remains or impression of a prehistoric organism preserved in petrified form or as a mold or cast in rock.
  3. 6. 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. 7. Extrusive igneous (volcanic) rock that is low in silica content, dark in color, and comparatively rich in iron and magnesium.
  5. 8. A hypothetical landmass in the Northern Hemisphere near the end of the Paleozoic Era: split apart to form North America and Eurasia.
  6. 10. Magma, molten rock, emerging as a liquid onto Earth's surface.
  7. 12. Where the magnetic north points (roughly) towards the geographic north pole. This is how the magnetic field is aligned today.
  8. 14. Where the magnetic north points in the opposite direction, and the north end of the magnetic field is close to the present-day south pole.
  9. 16. An instrument used for measuring magnetic forces, especially the earth's magnetism.
  10. 18. Zone of Earth's mantle lying beneath the lithosphere and believed to be much hotter and more fluid than the lithosphere.
  11. 20. A long, seismically active submarine ridge system situated in the middle of an ocean basin and marking the site of the upwelling of magma associated with seafloor spreading.