Presentation on theme: "Ch9 Wegener’s continental drift hypothesis stated that all the continents once joined together to form ____. a.two major supercontinents b.two major supercontinents."— Presentation transcript:
1Ch9Wegener’s continental drift hypothesis stated that all the continents once joined together to form ____.a.two major supercontinentsb.two major supercontinents and three smaller continentsc.one major supercontinentd.three major supercontinents
2Ch9The supercontinent in the continental drift hypothesis was called ____.a.Panthalassab.Pangaeac.Mesosaurusd.Africa
3Ch9What hypothesis states that the continents were once joined to form a single supercontinent?a.plate tectonicsc.continental driftb.seafloor spreadingd.paleomagnetism
4Ch9In the plate tectonics theory, the lithosphere is divided into ____.a.100 major platesb.7 major plates and many smaller platesc.many small plates, but no large platesd.50 major plates and many smaller plates
5Ch9 The lithospheric plates move an average of ____. a.5 inches per yearb.50 inches per yearc.5 centimeters per yeard.50 centimeters per year
6Ch9 A tectonic plate consists of ____. a.the crust and uppermost mantleb.the oceanic and continental crust onlyc.the crust and entire mantled.the asthenosphere only
7Ch9Which of the following is a geographic example of a transform fault boundary?a.the East African Rift valleyb.the San Andreas Faultc.the Mid-Atlantic Ridged.the Andes Mountains
8Ch9 New ocean crust is formed at ____. a.divergent boundaries c.continental volcanic arcsb.convergent boundariesd.transform fault boundaries
9Ch9Which of the following results when divergence occurs between two oceanic plates?a.seafloor spreadingb.a subduction zonec.an ocean trenchd.a volcanic island arc
10Ch9 What forms when one oceanic plate is forced beneath another plate? a.an ocean basinb.an ocean ridgec.a subduction zoned.a rift valley
11Ch9 Deep ocean trenches are associated with ____. a.ocean ridge systemsb.subduction zonesc.transform fault boundariesd.rift zones
12Ch9 What type of plate boundary is illustrated in Figure 9-1? a.transform fault boundaryb.divergent boundaryc.convergent oceanic-oceanic boundaryd.convergent oceanic-continental boundary
13Ch9Volcanic island arcs are associated with what type of plate boundary?a.divergent boundaryb.convergent continental-continental boundaryc.convergent oceanic-continental boundaryd.convergent oceanic-oceanic boundary
14Ch9Continental volcanic arcs are associated with what type of plate boundary?a.convergent continental-continental boundaryb.convergent oceanic-continental boundaryc.transform fault boundaryd.convergent oceanic-oceanic boundary
15Ch9If a deep ocean trench is located adjacent to a continent, active volcanoes would likely be found ____.a.seaward from the trenchb.along the axis of the trenchc.at the ends of the trenchd.landward from the trench
16Ch9Why are subduction zones not commonly found at convergent continental-continental boundaries?a.Continental lithosphere is too buoyant to be forced down into the mantle.b.Subduction zones are never found at convergent boundaries.c.Oceanic lithosphere is too buoyant to be forced down into the mantle.d.Continental lithosphere is too dense to be forced down into the mantle.
17Ch9Strips of alternating magnetic polarities found in rocks in the ocean basins ____.a.conflict with the theory of plate tectonicsb.provide evidence that Earth’s magnetic field has never reversed polarityc.indicate changes in Earth’s gravitation fieldd.provide evidence for seafloor spreading.
18Ch9What do the strips of low-intensity magnetism represent on the ocean floor?a.areas where there is no magnetismb.areas where the rocks have a normal polarityc.areas where the rocks have a reversed polarityd.areas of different types of rock.
19Ch9 What feature is labeled A in Figure 9-2? a.subduction zone b.trenchc.volcanic island arcd.continental volcanic arc
20Ch9According to Figure 9-2, if the plate labeled H descends into Earth’s interior, what will occur between the positions labeled Y and X?a.The rock at X will be cooler than the rock at Y.b.Earthquake foci will be shallower at Y and increase in depth at X.c.Earthquake foci will be deeper at Y and decrease in depth at X.d.Rifting will begin to occur between Y and X.
21Ch9According to Figure 9-2, if the plate labeled H descends into Earth’s interior, what will occur between the positions labeled Y and X?a.The rock at X will be cooler than the rock at Y.b.Earthquake foci will be shallower at Y and increase in depth at X.c.Earthquake foci will be deeper at Y and decrease in depth at X.d.Rifting will begin to occur between Y and X.