Plate Boundaries Flashcards
what are the three types of plate boundaries
- divergent
- convergent
- transform
what is the lithosphere
- the crust and the uppermost mantle which is solid
what can lithospheric plates be
continental crust, oceanic crust or a combination
what does the crust at the boundary define
used to define the boundary sub-type
what are divergent plate boundaries 4
- plates that move apart
- they form new basaltic crust
- create shallow earthquakes
- minor volcanism
what are the two sub-classes of divergent plate boundaries
- oceanic-oceanic divergent
- continental-continental divergent
oceanic-oceanic divergent plate boundaries have created…
rifting and spreading along a narrow zone have created the Mid-Atlantic ridge
what is the mid-atlantic ridge
mountain chain where volcanos and earthquakes are concentrated
example of two plates that represent the oceanic-oceanic divergent plate boundary
north-american plate Eurasian plate
continental-continental divergent plate boundary has created…
in east africa, an earlier stage of rifting and spreading has created parallel valleys ina. zone with volcanos and earthquakes
continental-continental divergent plate boundary example of two plates
african plate somali subplate
define convergent plate boundaries 5
- plates colliding together
- shallow and deep earthquakes
- mountains created
- trenches and volcanos sometimes
- continental arcs and island arcs
what are the three sub-classes of convergent plate boundaries
- oceanic-oceanic convergent
- continental- continental convergent
- continental-oceanic convergent
oceanic-oceanic convergent plate boundaries create… & the two examples
they form a deep-sea trench and a volcanic arc
mariana islands, marianas trench
the two plates colliding forming oceanic-oceanic convergent boundary
philippine plate ->
what are island arcs
- cerated by a subduction of. an oceanic plate
- the islands will form on the overriding plate
- oceanic trenches
example off island arcs
pacific ring of fire
oceanic-continental convergent causes…
the oceanic plate will subduct and a volcanic belt of mountains form at the continental plate margin
two plates forming a continental-oceanic plate boundary
nazca plate ->
wadati- benioff zone run down
- zone of earthquakes that extend away from the plate boundary
- earthquakes show depth zones (shallow near the boundary line and deeper the further awaY)
- depth also shows the descending oceanic plate
how is the wadati-benioff zone created
created by subduction of an oceanic plate
accreted terranes def
small crustal mass transported from afar
- fused on the continent through collision
continental- continental convergent plate boundary causes
the crust crumples and thickens, creating high mountains and a wide platea
two paltes colliding forming a continental-continental convergent palte boundary
indian-australian plate ->
transform plate boundaries def
- plates that slide past each-other
- create shallow earthquakes
- valleys and mountains are possible
what are the two subclasses of transform plate boundaries
- oceanic-oceanic transform
- continental- continental transform
continental-continental transform plate boundaries creates…
faults. the san andreas fault line is an example of two continental crusts sliding past eachother.
two plates that slide past eachother creating a transform boundary line
pacific plate and the north american plate
oceanic-oceanic transform plate boundary creates…
spreading centers are often offset by mid-oceanic ridge transform faults, where two oceanic plates slide horizontally past eachother
what are two plates that are sliding past each other creating an oceanic-oceanic transform plate boundary
north american plate and eurasian plate
how are hot spots created
- created by mantle plume = stationary heat source
- not a plate boundary
- shallow earthquakes
- volcanos
mantle plume def
stationary heat source
what are plate boundaries
occur at the contact of one or more lithospheric plates
wha can boundaries create
different landforms, and tectonic activity including volcanos and earthquakes
