6.4
Geologic activity that takes place within a plate rather than at plate boundaries is known as __________ activity.
intro plate
Which feature could form at a divergent plate boundary?
Rift Valley
A region where the phenomenon described in question 3 occurs often is called a(n) __________.
continental ark
result of divergent plate boundaries that occur within a continent
continental rifting
Seafloor spreading occurs because of
convection cells in the mantle.
edge where two plates move toward each other
convergent plate boundary
A large chunk of lithosphere that can move over Earth's surface is called a(n)
plate
The edge where two tectonic plates meet is called a(n)
plate boundary
The movement of plates over Earth's surface is called __________
plate tectonics
At a convergent plate boundary between oceanic and continental crust, the oceanic crust always plunges beneath the continental crust because oceanic crust is
denser.
edge where two plates move away from each other
divergent plate boundary
point on the Earth's surface directly above the place where an earthquake occurs
epicenter
Earthquakes occur only at transform plate boundaries.
false
Hotspot magma rarely penetrates oceanic crust.
false
Mid-ocean ridges occur at convergent plate boundaries.
false
The Atlantic Ocean currently is shrinking because of plate tectonics.
false
__________ occurs when an oceanic plate plunges beneath a continental plate at a convergent plate boundary.
subduction occurs
Some of the largest mountains in the world, including the Himalayas, occur where
two continental plates converge.
Earthquake epicenters outline the edges of tectonic plates.
True
Most geologic activity takes place
at plate boundaries.
large body of intrusive igneous rock at the edge of a subducting plate
batholith
Nearly all tectonic plates consist of
both oceanic and continental crust.
Each year, tectonic plates move a few
centimeters.
A line of volcanoes that forms where two oceanic plates converge is called a(n) __________.
island ark
line of coastal volcanic islands at the edge of a subducting plate
island ark
edge where two plates slip past each other
transform plate boundary
Convection cells in the mantle rise at deep-sea trenches.
true
Hotspot volcanoes form in a line as crust moves over a mantle plume.
true
Supercontinents form and break up in a cycle.
true
The Appalachian Mountains formed at a convergent plate boundary as Pangaea came together.
true
Volcanoes are unlikely where two continental plates converge.
true