Plate tectonics

What forms at divergent plate boundaries? new oceanic lithosphere new continental lithosphere

new oceanic lithosphere

Movement of plates away from each other at divergent boundaries typically shows which of the following average velocities? 5 cm per year 50 cm per year 5 m per year 5 km per year 50 km per year

5 cm per year

A continental volcanic arc is formed when which of the following conditions exists? Two slabs of continental crust collide. A piece of oceanic crust is subducted beneath another piece of oceanic crust. Two pieces of continental crust slide past each other at a transform boundary. A piece of continental crust is subducted beneath oceanic crust. A piece of oceanic crust is subducted below continental crust.

A piece of oceanic crust is subducted below continental crust.

Which of the following processes can be observed at the margins of lithospheric plates? faulting earthquakes volcanoes mountain building All of the responses are correct.

All of the responses are correct.

Australia is composed of old and thick

Continental crust

In studies of rock obtained from ocean basins all over Earth, the oldest ages obtained are approximately 200 million years before the present. Why have no older oceanic rocks been discovered? Scientists haven't sampled enough sites to find older rocks. Ocean floor is dispersed by volcanic eruptions. The age of Earth is 200 million years. As the lithospheric plates move around, most of the ocean floor rocks are pushed up to form mountains. Due to tectonic activity, rocks on the ocean floor are continually recycled.

Due to tectonic activity, rocks on the ocean floor are continually recycled.

Which of the following locations is a modern-day example of an active continental rift? Hawaiian Island chain west coast of South America East Africa and the Red Sea Aleutian Island arc Alpine Fault in New Zealand

East Africa and the Red Sea

How do plates move at divergent plate boundaries? Plates move toward one another. Plates do not move. Plates slide past one another. Plates move apart.

Plates move apart.

How do plates move at convergent plate boundaries? Plates move toward one another. Plates move apart. Plates slide past one another. Plates do not move.

Plates move toward one another.

How do plates move at transform plate boundaries? Plates move toward one another. Plates do not move. Plates slide past one another. Plates move apart.

Plates slide past one another.

found in the Atlantic Ocean between North America and Europe is composed of dense and relatively young rock

Seafloor crust

The slowly increasing distance between South America and Africa is due to

Seafloor spreading

Layered exposed by erosion can be seen when looking at the Grand Canyon in the United States

Sedimentary rock

At a divergent boundary, what is the relative motion of the plates on each side of the boundary? One plate is pushed over the other. One plate is pushed under the other. The plates move toward each other. The plates move away from each other. The plates slide past each other.

The plates move away from each other.

Which of the following processes drive plate tectonics? mantle plumes paleomagnetism transform faults convection subduction

convection subduction

Which of the following geologic processes and/or phenomena is not found at transform plate boundaries? earthquakes crustal thinning weathering offset stream channels volcanoes

volcanoes

As oceanic crust is subducted below continental crust, which of the following factors most directly drives the melting that will fuel volcanoes at the surface? density silica content composition temperature water

water

Which of the following statements is part of the continental drift hypothesis? Convective flow in the mantle is the underlying driving force of continental drift. Deep-sea drilling indicates that sediments increase in age with increasing distance from spreading ridges. A chain of volcanoes known as hot spot tracks can determine the direction of continental drift. A single supercontinent consisting of all Earth's landmasses once existed. The continents of South America and Africa fit together like pieces of a jigsaw puzzle.

A single supercontinent consisting of all Earth's landmasses once existed. The continents of South America and Africa fit together like pieces of a jigsaw puzzle.

Although new crust is being formed at divergent boundaries, Earth remains the same size. Which of the following statements provides the best reason for this? Magma continues to upwell at convergent boundaries. Lava is extruded via volcanoes at convergent boundaries. Earthquakes happen at divergent boundaries. An equal volume of crust is being consumed at convergent boundaries. Earth's gravitational field prevents it.

An equal volume of crust is being consumed at convergent boundaries.

Old Faithful Geyser at Yellowstone National Park in the United States acquires its energy from a

Hot spot

Since the breakup of Pangaea approximately 165 million years ago, a new supercontinent cycle has begun with the collision of which of the following continents? North America and Europe India and Asia North America and South America Africa and North America Europe and Siberia

India and Asia

What happens to the lithosphere at transform plate boundaries? Lithosphere moves down. Lithosphere is neither destroyed nor created, simply maintained or conserved. Lithosphere is destroyed. Lithosphere moves up. Lithosphere is created.

Lithosphere is neither destroyed nor created, simply maintained or conserved.

Which of the following statements about divergent boundaries is true? New continental crust is created at divergent boundaries. Ocean crust is consumed at a divergent boundary. New ocean crust is created at a divergent boundary. Mountains are created at divergent boundaries. Lithospheric plates move closer to each other at divergent boundaries.

New ocean crust is created at a divergent boundary.

Which of the following statements regarding transform plate boundaries is not correct? Transform plate boundaries connect two segments of the oceanic ridge system. Earthquakes are a common occurrence along transform plate boundaries. At transform plate boundaries, adjacent lithospheric plates slide past each other horizontally. New oceanic crust is formed at transform plate boundaries. Transform plate boundaries can occur within continental crust.

New oceanic crust is formed at transform plate boundaries.

Which of the following regions was not part of the large Southern Hemisphere continent of Gondwana? Antarctica South America North America India Africa

North America

The extremely deep ocean Marianas Trench is a result of

Subduction

When oceanic crust is subducted beneath continental crust, partial melting can occur. Which of the following best explains why the resultant magma rises through the crust toward the surface? The magma is continually being extruded at a trench between the converging plates. The magma is denser than the surrounding solid rock. The magma is less dense than the surrounding solid rock. The magma takes up less volume than the surrounding solid rock. The magma undergoes a decrease in silica content.

The magma is less dense than the surrounding solid rock

At a convergent boundary, what is the relative motion of plates on each side of the boundary? The plates slide past each other. The plates move toward each other. The plates move away from each other.

The plates move toward each other.

When moving away from a divergent boundary in either direction, which of the following statements is true? The rocks are rapidly converted to sediments. Oceanic crustal rocks are being consumed at the divergent plate boundary. The rocks become more felsic in composition. The rocks increase in age. The rocks decrease in age.

The rocks increase in age.

As oceanic crust is subducted, it melts, forming a body of magma. When this magma rises and interacts with the overlying continental crust, what change occurs in the composition of the magma? The silica content of the magma decreases. The composition of the magma causes it to produce mostly dark-colored minerals. The composition of the magma causes it to produce only light-colored minerals. The composition of the magma causes the density to increase. The silica content of the magma increases.

The silica content of the magma increases.

The formation of the Himalaya and the Tibetan Plateau was caused by which of the following events? There was a collision of two pieces of continental crust at a subduction zone. A slab of continental crust was subducted beneath a piece of oceanic crust. Oceanic crust was subducted beneath continental crust. Two slabs of continental crust slid past each other at a transform boundary. Oceanic crust was subducted beneath a second slab of oceanic crust.

There was a collision of two pieces of continental crust at a subduction zone

During the breakup of Pangaea, volcanic island arc systems may have formed that no longer exist. What likely happened to these arcs? After subduction, the rocks were melted to form new continental crust. They may have collapsed into trenches. They may have been subducted along continental margins. They may have been accreted onto continents after their formation. They may have been broken up along divergent boundaries.

They may have been accreted onto continents after their formation.

Why are volcanoes NOT found at transform boundaries? Transform boundaries do not cause changes to the pressure, temperature, or composition of the mantle. Transform boundaries cause decreases in temperature that exactly offset increases in pressure of the mantle. Transform boundaries cause increases in temperature that exactly offset decreases in pressure of the mantle. Transform boundaries cause changes to the pressure, temperature, or composition of the mantle.

Transform boundaries do not cause changes to the pressure, temperature, or composition of the mantle.

Currently the Juan de Fuca plate is interacting with the North American plate where inland volcanoes and deep focus earthquakes are occurring. What type of plate boundary is this? a transform boundary a mantle plume a continental rift zone a convergent plate boundary a divergent plate boundary

a convergent plate boundary

Continued movement of the continental crust on the west side of the San Andreas fault could result in which of the following features? an island an oceanic island arc a continental volcanic arc new oceanic crust a coastal mountain range

an island

The East African rift is a divergent plate boundary that is splitting the continent of Africa into two pieces. What will eventually form around this divergent boundary? a hurricane a convergent boundary a transform boundary a continent an ocean

an ocean

Which of the following techniques can be used to recreate the configuration of supercontinents that existed before Pangaea? age of the sea floor ages of igneous and metamorphic rocks changes in the position of Earth's magnetic field apparently wandering polar paths marine fossils

apparently wandering polar paths

What geologic process initiated the breakup of Pangaea approximately 165 million years ago? continental rifting formation of continental volcanic arcs sea floor spreading formation of volcanic island arcs formation of mountain ranges

continental rifting

What are the three categories of plate boundaries? reverse convergent strike-slip divergent transform

convergent divergent transform

In general, where do earthquakes AND volcanic eruptions occur? convergent plate boundaries divergent plate boundaries away from plate boundaries transform plate boundaries

convergent plate boundaries divergent plate boundaries

The earthquakes that occur in Southern California generally occur above a

fault

In general, where do volcanoes form in subduction zones? on the subducting plate, at the convergent boundary on the overriding plate, at the convergent boundary on the subducting plate, away form the convergent boundary on the overriding plate, away form the convergent boundary

on the overriding plate, away form the convergent boundary

The occurrence of stream channels that have been offset along a transform fault are indicative of which of the following conditions? stretching of the rocks has occurred opposite sides of the fault have shifted horizontally streams can't flow across the boundary opposite sides of the fault have shifted vertically stream flow has been diverted by volcanic eruptions

opposite sides of the fault have shifted horizontally

What type of stress is most directly associated with transform faults? tensional stress bending stress torsional stress shear stress compressional stress

shear stress

Which of the following features is considered a destructive plate margin? continental rift Hawaiian Islands San Andreas fault oceanic ridge subduction zone

subduction zone

Which of the following lithospheric plates is not included among the seven largest? the South American plate the Philippine plate the Australian-Indian plate the Antarctic plate the African plate

the Philippine plate

When oceanic and continental crust collide at a subduction zone, one plate is forced under the other. The angle at which the subducting plate descends is due to which of the following factors? the composition of the plate being subducted the age of the plate being subducted the depth of the water over the plate being subducted the amount of water in the plate being subducted the density of the plate being subducted

the age of the plate being subducted the density of the plate being subducted

Earth's lithospheric plates are composed of crust and which of the following layers? the middle portion of the mantle the outermost portion of the core the innermost portion of the mantle the core the outermost portion of the mantle

the outermost portion of the mantle