Concept Review

Name Class Date Skills Worksheet Concept Review

In the space provided, write the letter of the definition that best matches the term or phrase.

______1. Pangaea a. region along a plate boundary where one plate moves under another ______2. lithosphere b. piece of lithosphere with a unique ______3. rift valley geologic history c. crack in the center of a mid-ocean ridge ______4. sea-floor spreading d. supercontinent formed about 300 million ______5. paleomagnetism years ago residual magnetism of rock ______6. terrane e. f. process by which new sea floor forms ______7. mid-ocean ridge g. layer that forms the thin outer shell of Earth ______8. subduction zone h. cycle in which heated material rises and cooler material sinks ______9. continental drift i. undersea mountain range ______10. convection cell j. hypothesis that the continents once formed a single landmass

In the space provided, write the letter of the answer choice that best completes each statement or best answers each question.

______11. What kind of fossil evidence supported Wegener’s hypothesis? a. fossils hinting at a land bridge between South America and Africa b. fossils proving Mesosaurus never lived in Africa c. plant fossils showing that cold areas used to be tropical d. sea fossils proving the continents had plowed through the ocean floor

______12. Sea-floor spreading was a key discovery because it showed a. that mid-ocean ridges exist. b. how continents move. c. why some rocks have reversed polarity. d. that mid-ocean ridges have rifts at the center.

______13. Tectonic plates ride on the layer of Earth’s mantle called the a. lithosphere. b. oceanic crust. c. continental crust. d. asthenosphere.

______14. Scientists identify tectonic plate boundaries primarily by studying a. the outlines of the continents. b. earthquake data. c. the Pacific Ring of Fire. d. active volcanoes.

______15. A plate boundary at which two plates slide past each other horizontally is a a. divergent boundary. b. convergent boundary. c. transform boundary. d. subduction zone.

______16. Convection currents cause movement of tectonic plates by a. making water in Earth’s core boil. b. creating ridge push and slab pull. c. making hot mantle material sink. d. turning lithosphere to asthenosphere.

______17. New, smaller continents may form from larger continents through a. rifting. b. accretion. c. paleomagnetism. d. subduction.

______18. What often forms when large terranes and continents collide? a. mid-ocean ridges b. atolls c. seamounts d. major mountain chains

______19. The movements of the continents a. discourage the development of unique species. b. keep climates constant. c. create fewer mountain ranges. d. isolate some populations of organisms.

______20. One likely result of the supercontinent cycle is that a. the continents will continue to get further apart. b. California will move closer to the equator. c. the Mediterranean Sea will close. d. the Atlantic Ocean will disappear.