Plate Tectonics Assignments
Across
- 2. Long, narrow depression that forms when continental crust begins to separate at a divergent boundary.
- 10. Place where two of Earth’s tectonic plates are moving toward each other; is associated with trenches, inlands arcs, and folded mountains.
- 11. Hess’s theory that new ocean crust is formed at mid-ocean ridges and destroyed at deep-sea trenches; occurs in a continuous cycle of magma intrusion and spreading.
- 13. Changes in Earth’s magnetic field over geologic time, recorded in ocean-floor rocks and continental basalt flows.
- 15. Ancient landmass made up of all the continents that began to break apart about 200 million years ago.
Down
- 1. Tectonic process associated with convection currents in Earth’s mantle that occurs as the weight of the subducting plate pulls the trailing lithosphere into a subduction zone.
- 3. States that Earth’s crust and upper mantle are broken into plates, which are huge rock slabs that move in different directions and at different rates over Earth’s surface.
- 4. Process by which one tectonic plate slips beneath another tectonic plate.
- 5. Tectonic process associated with convection currents in Earth’s mantle that occurs when the weight of an elevated ridge pushes an oceanic plate toward a subduction zone.
- 6. Place where two of Earth’s tectonic plates are moving apart; is associated with volcanism, earthquakes, and high heat flow, and is found primarily on the seafloor.
- 7. Study of Earth’s magnetic record using data gathered from iron-bearing minerals in rocks that have recorded the orientation of Earth’s magnetic field at the time of their formation.
- 8. Wegener’s hypothesis that Earth’s continents were joined as a single landmass, called Pangaea, that broke apart about 200 million years ago and slowly moved to their present situations.
- 9. Place where two tectonic plates slide horizontally past each another that is characterized by long faults and shallow earthquakes.
- 12. Device used to map the ocean floor that detects small changes in magnetic fields.
- 14. Line on a map that connects points of the same age.