Chapter 7

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Across
  1. 2. ridge The mountain ranges in the middle of the oceans are called mid-ocean ridges.
  2. 4. spreading Seafloor spreading is the process by which new oceanic crust forms along a mid-ocean and older oceanic crust moves away from the ridge.
  3. 5. tectonics states that earths surface is made of rigid slabs of rock or plants that move with respect to each other.
  4. 7. polarity-a state in which magnetized objects would reverse direction and orient themselves to point south.
Down
  1. 1. drift Wegener proposed the hypothesis of continental drift, which suggested that continents are in constant motion on the surface of earth.
  2. 3. polarity normal polarity- a state in which magnetized objects, such as compass needles, will orient themselves to point north.
  3. 5. He proposed that all the continents were once part of a supercontinent called Pangaea.
  4. 6. reversal occurs and the magnetic field reverses direction