CSS - PMS - CCE - PCS - Geography
Plate Tectonics
Continental crust is generally:
A. Thicker and less dense than oceanic crust
B. Thinner and denser
C. Made only of basalt
D. Continuously recycled every 10 Ma
Correct Answer: A
Continental crust is compositionally more felsic and typically thicker.
CSS - PMS - CCE - PCS - Geography
Plate Tectonics
The Hawaiian island chain records:
A. Pacific Plate motion over a hotspot
B. Atlantic spreading
C. Himalayan collision
D. Transform motion in California
Correct Answer: A
Age progression along the chain reflects plate movement over a long-lived volcanic source.
CSS - PMS - CCE - PCS - Geography
Plate Tectonics
Hotspots are commonly interpreted as:
A. Localized mantle upwelling relatively independent of plate boundaries
B. Only transform faults
C. Only trenches
D. River sources
Correct Answer: A
Hotspot volcanism can occur within plates, as in Hawaii.
CSS - PMS - CCE - PCS - Geography
Plate Tectonics
The Pacific Ring of Fire is characterized by abundant:
A. Earthquakes and volcanoes
B. Deserts and dunes only
C. Coral reefs only
D. Passive margins
Correct Answer: A
Subduction zones around much of the Pacific produce intense seismicity and volcanism.
CSS - PMS - CCE - PCS - Geography
Plate Tectonics
Most tectonic earthquakes occur:
A. Near plate boundaries
B. Only at the Equator
C. Only in continental interiors
D. Only at volcano summits
Correct Answer: A
Plate margins concentrate deformation and fault slip.
CSS - PMS - CCE - PCS - Geography
Plate Tectonics
The Wadati-Benioff zone is a zone of:
A. Earthquakes along a subducting slab
B. Volcanoes at a ridge only
C. River erosion
D. Glacial deposition
Correct Answer: A
Earthquake foci define the descending slab in subduction zones.
CSS - PMS - CCE - PCS - Geography
Plate Tectonics
A deep-ocean trench marks many:
A. Subduction zones
B. Divergent ridges
C. Passive margins
D. Hotspot tracks only
Correct Answer: A
Trenches form where an oceanic plate bends into a subduction zone.
CSS - PMS - CCE - PCS - Geography
Plate Tectonics
The East African Rift is an example of:
A. Continental rifting
B. Oceanic-oceanic collision
C. Transform boundary only
D. Stable shield with no extension
Correct Answer: A
East Africa is undergoing active continental extension.
CSS - PMS - CCE - PCS - Geography
Plate Tectonics
A rift valley is commonly associated with:
A. Continental divergence
B. Continental collision
C. Transform motion only
D. Subduction only
Correct Answer: A
Extension and normal faulting create elongated rift depressions.
CSS - PMS - CCE - PCS - Geography
Plate Tectonics
Continental-continental convergence commonly produces:
A. Large fold mountains
B. Deep sea-floor spreading ridge
C. Oceanic island arc only
D. Passive margin
Correct Answer: A
Buoyant continents resist deep subduction and crust thickens during collision.
CSS - PMS - CCE - PCS - Geography
Plate Tectonics
Oceanic-continental convergence commonly produces:
A. A continental volcanic arc and trench
B. Only a rift valley
C. A mid-ocean ridge
D. No earthquakes
Correct Answer: A
Oceanic lithosphere subducts beneath more buoyant continental lithosphere.
CSS - PMS - CCE - PCS - Geography
Plate Tectonics
Oceanic-oceanic convergence commonly produces:
A. Island arcs and trenches
B. Rift valleys
C. Passive margins
D. Shield areas
Correct Answer: A
One oceanic plate subducts, forming a trench and volcanic island arc.
CSS - PMS - CCE - PCS - Geography
Plate Tectonics
The Japan island arc is mainly associated with:
A. Subduction
B. Continental rifting only
C. A passive margin
D. No plate boundary
Correct Answer: A
Subduction around Japan drives arc volcanism and earthquakes.
CSS - PMS - CCE - PCS - Geography
Plate Tectonics
The Andes are mainly related to subduction of the:
A. Nazca Plate beneath South America
B. South American Plate beneath Nazca
C. Pacific Plate beneath Africa
D. Indian Plate beneath Australia
Correct Answer: A
Oceanic Nazca lithosphere subducts beneath the South American Plate.
CSS - PMS - CCE - PCS - Geography
Plate Tectonics
The Himalayas formed primarily by collision between the:
A. Indian and Eurasian plates
B. Pacific and Nazca plates
C. African and South American plates
D. Arabian and African plates only
Correct Answer: A
Continental collision after closure of Tethyan oceanic domains built the Himalaya.
CSS - PMS - CCE - PCS - Geography
Plate Tectonics
The Mid-Atlantic Ridge is a:
A. Divergent boundary
B. Transform boundary only
C. Subduction trench
D. Collision mountain belt
Correct Answer: A
Atlantic seafloor spreads from this ridge system.
CSS - PMS - CCE - PCS - Geography
Plate Tectonics
The San Andreas Fault is a classic:
A. Transform boundary
B. Divergent ridge
C. Oceanic trench
D. Continental collision zone
Correct Answer: A
The Pacific and North American plates slide past one another there.
CSS - PMS - CCE - PCS - Geography
Plate Tectonics
At a transform boundary, plates move mainly:
A. Horizontally past each other
B. Directly apart
C. Directly together
D. Upward only
Correct Answer: A
Transform faults accommodate lateral plate motion.
CSS - PMS - CCE - PCS - Geography
Plate Tectonics
A divergent boundary involves plates moving:
A. Apart
B. Toward each other
C. Only clockwise
D. Without relative motion
Correct Answer: A
Extension separates plates and may create new lithosphere.
CSS - PMS - CCE - PCS - Geography
Plate Tectonics
A convergent plate boundary involves plates moving:
A. Toward each other
B. Apart
C. Parallel without relative motion
D. Vertically only
Correct Answer: A
Convergence causes collision or subduction.