Earth/Space Science
convergent boundaries
a boundary in which two plates move together
transform fault boundary
a boundary in which two plates slide past each other without creating or destroying lithosphere
what is the ring of fire?
a chain of volcanoes circling the Pacific Basin
at divergent boundaries in the ocean, magma rises and melts because of ___
a decrease in pressure
at divergent plate boundaries in the ocean, magma rises and melts because of ____
a decrease in pressure
divergent boundaries
a region where the rigid plates are moving apart, typified by the oceanic ridges
In the theory of plate tectonics, what makes up a typical plate that moves across Earth's surface?
a section of both continental and oceanic lithosphere
what is the major type of stress that occurs at convergent plate boundaries?
compressional stress
the driving force behind plate movement is the process of ____ that occurs in the mantle.
convection
the motion of tectonic plates is part of a larger system that includes _____.
convection currents in the mantle
continental volcanic arcs are associated with the ____ plate boundary
convergent oceanic-continental
Volcanic island arcs are associated with which type of plate boundary?
convergent oceanic-oceanic
at divergent boundaries, hot mantle rock rises and ____ occurs
decompression melting
when pressure drops enough, _____ occurs.
decompression melting
the type of plate boundary where plates move apart, resulting in upwelling of material from the mantle to create new seafloor, is referred to as a _____ plate boundary
divergent
A rift valley forms at a ____.
divergent boundary
Unlike what happens to the lithosphere at a divergent or a convergent boundary, the lithosphere at a transform fault boundary _____.
does not transfer rocks to or from the mantle
the type of deformation in which the object permanently changes size and shape without fracturing is called ___
ductile deformation
which feature or event is common at a transform fault boundary?
earthquakes
which is not a form of rock deformation?
erosional deformation
what are the major types of mountains?
folded, fault-block, volcanic
most intraplate volcanic activity occurs where ____
hot mantle plumes rise toward the surface within a plate
descending into Earth's interior, temperature, as well as pressure on rock, ___
increases
which feature formed at a convergent boundary?
the Himalayas, a mountain range at the northern edge of the India plate
which is a geographic example of a transform fault boundary?
the San Andreas fault
Which is an example of a divergent boundary?
the crest of the mid-Atlantic ridge, where the new ocean floor is formed
if erosion stripped off the top of a dome, what would be found?
the oldest rocks are exposed in the center
most magma forms from ____
the partial melting of solid rock in the crust or upper mantle
which is not a type of stress seen in rocks?
transitional stress
Plate motion averages about ____
5 centimeters per year
plate tectonics
A theory stating that the earth's surface is broken into plates that move.
the thermal convection that drives plate motion is caused by _____
an unequal distribution of heat
in what two plate tectonic setting do most volcanoes occur?
at divergent plate boundaries (ocean ridges or rifts) and at convergent plate boundaries at subduction zones
in what two plate tectonic settings do most volcanoes occur?
at divergent plate boundaries (ocean ridges or rifts) and at convergent plate boundaries at subduction zones
volcanoes most often occur at plate boundaries and _____
at intraplate hot spots
why are divergent boundaries also called spreading centers?
because they are the areas where sea-floor spreading begins
according to the plate tectonic theory, a plate can be made up of _____.
both continental and oceanic litosphere
what type of volcano is built almost entirely from ejected lava fragments?
cinder cone
a volcano that is fairly symmetrical and has both layers of lava and pyroclastic deposits is a ____
composite cone volcano
an igneous intrusive feature that forms from a lens-shaped mass of magma that arches the overlying strata upward is called a ____
laccolith
if a deep-ocean trench is located adjacent to a continent, active volcanoes would likely be found ____
landward from the trench
what is not a major component of magma
lava
what is destroyed at a convergent boundary?
lithosphere at the edge of a plate
what factor plays a major part in determining the form of a volcano?
magma composition
what factor plays a major part in determining the form of a volcano?
magma compostion
both slap-pull and ridge-push are mechanisms that cause ____.
ocean plates to be subducted into the mantle
plate
one of the numerous rigid sections of the lithosphere that moves as a unit over the material of the asthenoshpere
structures that form from cooling and hardening of magma beneath Earth's surface are ____
plutons
the particles produced in volcanic eruptions are called ____
pyroclastic material
which list places the magma types in order of decreasing viscosity?
rhyolitic, andesitic, basaltic
brittle deformation is generally seen in ____
rocks with strong intermolecular bonds
the broad, slightly dome-shaped volcanoes of Hawaii are ____
shield volcanoes
magma viscosity is directly related to its ____
silica content
what commonly horizontal intrusive igneous body is formed when magma is injected parallel to sedimentary rocks?
sill
how explosively or quietly a volcano erupts is not affected by ____
size of the volcano cone
which process or processes are involved in the sinking of cold ocean plates into the mantle?
slab-pull and ridge-push acting together
what feature is similar to a batholith but has less than 100 square kilometers exposed?
stock
which type of landform develops at plate boundaries where one oceanic plate descends beneath another?
volcanic island arc
the volcanic landform that is formed when the more resistant volcanic pipe remains after the most of the cone has been eroded is called a _____
volcanic neck
the thickest part of the crust occurs in ___
young mountain ranges
