Plate Boundaries (1) Flashcards
a long, underwater rift valley winding through the ocean floor
mid-ocean ridge
Divergent boundaries occur on the seafloor resulting in _________
seafloor spreading
a divergent boundary between the South
American and African plates
Mid-Atlantic Ridge
The longest chain of mountains is located ___________
underwater
a large portion of the ridge
exposed above sea level can be found in ____________ – one of the very few
places where one can stand on the ridge between two diverging tectonic
plates on dry land
Iceland
Another example of diverging plates, which will result in the formation
of a new ocean can be found in ________
East Africa
New crust is usually formed at a ___________
mid-oceanic ridge
A type of boundary that is characterized by
plates grinding or sliding past one another horizontally along a long,
vertical fault.
transform fault boundary
____________ are made of hot
rocks that originate way below the asthenosphere,
deep within Earth
mantle plumes
a concentration of heat in the mantle
producing magma, which extrudes onto
the surface of Earth
hot spot
An example of a hot mantle plume is __________
Hawaii
the hypothesis which suggested that new
oceanic crust is formed at the crests of
mid-oceanic ridges, where divergence
occurs
seafloor spreading
process by which an oceanic plate sinks
into the mantle along a convergent
boundary
subduction
where tectonic plates interact
plate boundary
the hypothesis which suggested that new
oceanic crust is formed at the crests of
mid-oceanic ridges, where divergence
occurs
seafloor spreading
a chain of volcanic islands found near
a trench where active subduction of
one oceanic plate beneath another is
occurring
island arc
mountains formed associated with
the subduction of oceanic lithosphere
beneath a continent
volcanic arc
where neighboring tectonic plates move
toward each other
convergent boundary
where neighboring tectonic plates move
away from each other
divergent boundary
a theory that proposes that the outer surface of Earth is composed of individual
plates interact in various ways, and thereby produce earthquakes,
volcanoes, mountains, and the crust itself.
plate tectonics theory
__________ boundaries produce geologic features depending on the materials on which the
converging plates are made of
convergent boundaries
__________ and _____________ account for oceanic
trench, volcanic and seismic activity, and mountain along the coast
Converging continental and oceanic plates
__________________ account for oceanic trench, seismic activity, and volcanic arc above the subducted plate
Converging oceanic
plates
_____________ account for thick and elevated plateaus and mountain ranges
Converging continental plates
TRUE/FALSE:
Most of the world’s volcanoes form along or near convergent and “transform-fault” boundaries.
FALSE; divergent
TRUE/FALSE:
According to the Plate Tectonics theory, seafloor spreading takes place at a
“convergent” boundary.
FALSE; divergent
TRU/FALSE:
An oceanic trench, seismic activity, and volcanic mountains along the edge of
a continent are characteristics of “oceanic-oceanic” plate convergence
oceanic continental
TRUE/FALSE:
The formation of the Philippine archipelago is characterized by the processes
that occur due to continental to continental convergence.
oceanic-oceanic plate convergence
TRUE/FALSE:
The Mid-Atlantic Ridge is a geologic feature produced by divergent boundaries.
TRUE
