Name: ____________________________________________________________________________________ Date __________________________ Hour ____________ Study Guide - Plate Tectonics ______ 1. The youngest part of the ocean floor is found ______ a. along deep sea trenches c. near ocean ridges b. where ocean sediments are thickest d. where Earth’s magnetic field changes polarity ______ 2. At oceanic-oceanic convergent boundary, ______ a. new crust is created c. old crust is recycled by subduction b. old crust is deformed or fractured d. plates side past one another ______ 3. Convection currents transfer thermal energy _____ a. between continents c. from warmer regions to cooler regions b. from cooler regions to warmer regions d. as a result of buoyancy ______ 4. The downward part of a convection current causes a sinking force that _____ a. pulls tectonic plates toward one another b. moves plates apart from one another c. lifts and splits the lithosphere d. creates a divergent boundary ______ 5. What happens to ocean floor as is moves farther away from a rift valley? a. it gets older b. it gets wider c. it gets younger d. it gets thinner ______ 6. Compared to ocean crust near deep-sea trenches, crust near ocean ridges is _____ a. younger b. older c. the same age d. magnetically reversed ______ 7. Divergent boundaries __________________ happen at oceanic-oceanic boundaries. a. always b. sometimes c. never d. mostly ______ 8. Convergent boundaries move_______________________________________________________ a. past each other b. towards each other c. away from each other d. next to each other ______ 9. Each cycle of spreading and intrusion of magma during seafloor spreading results in _____ a. magnetic reversals b. new ocean crust c. subduction d. plates colliding ______ 10. Features found at divergent boundaries include _____ a. ocean ridges b. deep-sea trenches c. crumpled mountains d. island arc volcanoes ______ 11. Continental-continental plate collisions produce _____ a. island arcs b. rift valleys c. deep-sea trenches d. very tall mountain ranges ______ 12. Crust is neither destroyed nor formed by which of the following boundaries? a. convergent b. divergent c. transform d. magnetic ______ 13. The driving forces of tectonic plates are related to convection currents in Earth’s _____ a. crust b. mantle c. inner core d. outer core ______ 14. A vast, underwater mountain chain is called a(n) _____ a. deep-sea trench b. ocean ridge c. oceanic crust d. ocean floor sediments ______ 15. A narrow, elongated depression in the seafloor is called a(n) _____ a. deep-sea trenches b. oceanic crust c. ocean ridge d. ocean floor sediment 16. Listed below are the steps involved in the process of seafloor spreading. Sequence the steps in the correct order. The seafloor contracts and sinks Crust spreads along an ocean ridge and magma fills the gap that is created New seafloor moves away from the ridge, cools, and becomes more dense than the material beneath it Hot magma which is less dense than surrounding material, is forced toward the crust New ocean floor forms as the magma hardens 17. Complete the table below. Type of Boundary 1 Plates Involved Direction of Movement Resulting Feature or Phenomena Ocean Ridges Moving apart Rift valley Toward one another Deep-sea trench Toward one another Volcanic mountain range Divergent 2 3 Convergent 4 5 Convergent 6 Uplifted mountain range Oceanic-oceanic and continental-continental Slide past one another Match the letter that appears in the diagram with the appropriate feature listed below.(A-G) 18. ____________trench 19. ____________ mountain range 20. __________mid-ocean ridge 21. ____________ volcanic island arc 22. __________ volcanic mountain range 24. ____________subduction zone 2 Match the boundary with its name. (1-5) 25. _________divergent boundary 27. _________convergent: oceanic-oceanic 23. ____________ rift valley 26. _________transform boundary 28. _________ convergent: oceanic-continental 29. _________convergent: continental-continental 1 A F 5 A B E 3 D D C 4 G G