Plate Tectonics and Continental Drift Vocab

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Across
  1. 2. boundary that forms when two plates slide past each other; causes earthquakes
  2. 8. boundary that forms when two plates collide; causes subduction, trenches, mountains, volcanoes
  3. 10. an underwater mountain range that stretches along the center of much of Earth's ocean floor that forms when two oceanic plates diverge
  4. 13. sections of Earth’s crust and upper part of the mantle (the lithosphere)
  5. 14. feature formed where subduction occurs; island arcs and volcanic arcs can be created
  6. 16. proposed the theory of seafloor spreading in the 1960's
  7. 17. a sensing device used to detect magnetic fields on the rocks on the ocean floor
  8. 18. all of the crust and the upper solid portion of the mantle
  9. 19. the process by which the ocean floor sinks into the mantle where crust is melted and recycled
  10. 20. fossil plant found in Africa, Australia, India, South America, and Antarctica
  11. 21. Wegener’s hypothesis that continents have slowly moved to their present day locations.
Down
  1. 1. hot, less dense material below Earth's crust rises toward the surface at the mid- ocean ridges, flows sideways, carrying the seafloor away from the ridge in both directions leaving the youngest rocks at/near the ridge and the oldest farther away
  2. 3. the plasticlike layer of the mantle located below the lithosphere
  3. 4. when Earth's magnetic force runs the opposite way. Recorded in the rocks along the mid-ocean ridge. Occurs over thousands or millions of years
  4. 5. cycle of heating, rising, cooling, and sinking that occurs in the mantle that is the driving force of plate tectonics
  5. 6. reptile fossil found in South America and Africa
  6. 7. boundary that forms when two plates move apart; causes mid-ocean ridges, rift zones, earthquakes
  7. 9. valley that forms when two plates diverge
  8. 11. German scientist who proposed the hypothesis of continental drift; his ideas were initially rejected
  9. 12. the theory that Earth’s crust and part of the upper mantle are broken into sections called plates that move on a plasticlike layer of the mantle (asthenosphere)
  10. 15. mountains similar to those in Greenland and Europe