EarthSci_PlateTectonics_reviewquest

Plate Tectonics Key Concepts Important terms Continental drift Deep-ocean trench Magnetic reversal Lithosphere Continental volcanic arc Mantle Convection Pangaea Island arc Convergent boundary Aesthenosphere Fracture zone Divergent boundary Rift valley Mantle plume Transform boundary Benioff zone Hot spot Wadati-Benioff Zone Seafloor spreading Paleomagnetism A Partial List of Review Questions o Briefly describe the view held by most geologists prior to the 1960s regarding the ocean basins and continents. o What group of geologists were the least receptive to the continental drift hypothesis, and why? o List and explain the sequence of evidence Wegener presented to support the continental drift hypothesis. What was the first line of evidence that led early investigators to suspect that the continents were once connected? o Explain why the discovery of the fossil remains of Mesosaurus in both South America and Africa, but nowhere else, supports the continental drift hypothesis. o Early in the twentieth century, what was the prevailing view of how land animals apparently migrated across vast expanses of open ocean? o How did Wegener account for evidence of glaciers in portions of South America, Africa, and India, when areas in North America, Europe, and Asia supported lush tropical swamps? o Describe two aspects of Wegener’s continental drift hypothesis that were objectionable to most Earth scientists. o What new findings about the ocean floor did oceanographers discover after World War II? o Describe the internal structure and layering of the earth o Compare and contrast Earth’s lithosphere and asthenosphere. o List the seven largest lithospheric plates. o Sketch, define, and describe the different plate boundaries and their movements? How do these processes result in either the formation of new oceanic crust, the destruction of ocean or continental crust, or neither? o What is the average rate of seafloor spreading in modern oceans? o What is the difference between seafloor spreading and continental rifting? What are the steps involved in process of continental rifting? o List four features that characterize the oceanic ridge system. o Why is the surface area of the earth not continually increasing? o Explain why the rate of lithosphere production is roughly equal to the rate of lithosphere destruction. o Why does oceanic lithosphere subduct while continental lithosphere does not? o How are island volcanic arcs different from continental volcanic arcs? o Briefly describe how mountain belts such as the Himalayas form. o Sketch or describe how two plates move in relation to each other along a transform plate boundary. o List two characteristics that differentiate transform faults from the two other types of plate boundaries. o Name two plates that are growing in size. Name a plate that is shrinking in size.