mantle
Which layer of Earth possesses the greatest thickness
basalt
Which of the following rocks best represents the typical composition of oceanic crust?
continental crust
Which region of Earth is composed of abundant amounts of granite?
thermal energy from within earth
What is the major source of energy that drives the movements of the lithospheric plates on Earth?
outer core
The magnetic field of Earth is thought to originate in which of the following layers?
Because the asthenosphere is composed of weak, hot, and dense rock, the cold, rigid, less dense lithospheric plates are capable of moving on it.
Which of the following responses best describes why the lithospheric plates are able to move around on the surface of Earth?
A shadow zone exists where S waves do not arrive on the side of Earth opposite the focus of an earthquake.
How do we know that the outer core of Earth is liquid?
the Philippine plate
Which of the following lithospheric plates is not included among the seven largest?
the outermost portion of the mantle
Earth's lithospheric plates are composed of crust and which of the following layers?
faulting, earthquakes, volcanoes, mountain building
Which of the following processes can be observed at the margins of lithospheric plates?
Due to tectonic activity, rocks on the ocean floor are continually recycled.
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?
a convergent plate boundary
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?
The plates move toward each other.
At a convergent boundary, what is the relative motion of plates on each side of the boundary?
1) the age of the plate being subducted
2) the density of the plate being subducted
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?
water
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?
The magma is less dense than the surrounding solid rock
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?
A piece of oceanic crust is subducted below continental crust.
A continental volcanic arc is formed when which of the following conditions exists?
An equal volume of crust is being consumed at convergent boundaries.
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?
The silica content of the magma increases.
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?
There was a collision of two pieces of continental crust at a subduction zone.
The formation of the Himalaya and the Tibetan Plateau was caused by which of the following events?
The plates move away from each other.
at a divergent boundary, what is the relative motion of the plates on each side of the boundary?
New ocean crust is created at a divergent boundary
Which of the following statements about divergent boundaries is true?
+Lithospheric plates move closer to each other at divergent boundaries.
+New ocean crust is created at a divergent boundary.
+Ocean crust is consumed at a divergent boundary.
+New conti
5 cm per year
Movement of plates away from each other at divergent boundaries typically shows which of the following average velocities?
The rocks increase in age.
When moving away from a divergent boundary in either direction, which of the following statements is true?
+The rocks increase in age.
+The rocks become more felsic in composition.
+The rocks are rapidly converted to sediments.
+Oceanic crustal rocks are
New oceanic crust is formed at transform plate boundaries
Which of the following statements regarding transform plate boundaries is not correct?
+Transform plate boundaries can occur within continental crust.
+New oceanic crust is formed at transform plate boundaries.
+At transform plate boundaries, adjacent lit
an island
Continued movement of the continental crust on the west side of the San Andreas fault could result in which of the following features?
opposite sides of the fault have shifted horizontally
The occurrence of stream channels that have been offset along a transform fault are indicative of which of the following conditions?
shear stress
What type of stress is most directly associated with transform faults?
volcanoes
Which of the following geologic processes and/or phenomena is not found at transform plate boundaries?
Ocean-Continent Convergence
Can create very large mountains like the Cascade Range, WA, as a result of partial melting of molten rock
Ocean-Continent Convergence
Creates abundant volcanic activity on the overriding continental plate
Ocean-Ocean
Japan is an example
Ocean-Ocean
Creates volcanic activities resulting in volcanoes growing up from the ocean floor
Continent - Continent convergence
Doesn't create volcanic activity
seafloor spreading
The slowly increasing distance between South America and Africa is due to
a hot spot
Old Faithful Geyser at Yellowstone National Park in the United States acquires its energy from
sedimentary rock
Layered _________exposed by erosion can be seen when looking at the Grand Canyon in the United States
continental crust
Australia is composed of relatively old and thick
subduction
The extremely deep ocean Marianas Trench is a result of
Seafloor crust
________found in the Atlantic Ocean between North America and Europe is composed of dense and relatively young rock.
fault
The earthquakes that occur in Southern California generally occur above a
lithosphere
Earth's outer layer is composed of seven dominant plates. What is the name of this rigid outer layer?
plates sliding past one another
What type of plate interaction produces the San Andreas Fault?
a fault creep along the Calaveras Fault
The bend in the stone walls in the town of Hollister, California are a result of __________.
right-lateral movement along the San Andreas strike-slip fault
The offset of Wallace Creek is caused by __________.
As plates move, stress builds up at the boundary. When the boundary eventually snaps, energy is released as an earthquake.
What causes an earthquake such as the one that occurred in San Francisco in 1906?