Download Plate Movement: ln, Out` and Sideways

Geology
Plate Movement: ln, Out' and Sideways
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The lithosphere, or solid parl of the Earth, is divided into plates. The places where
or hot,
these plates meet are called ptate boundaries.The plaies ride on the asthenosphere,
fluid, upper portion of the mantle. There are three types of movement that seem to occur
at the plate boundaries or zones.
The first type of zone is called lhe spreading zone. As the name indicates, this is an
on the ocean
area where plates would spread away f rom each other. Most spreading occurs
crust is
ocean
floor, along ihe mid-ocean ridges. Where this ocean spreading occurs, new
formed.
The second type of zone isafractureor fault zone. Atthis meeting place, plates slide
past each other. No new Earth matter is created, nor is any lost. Shallow earthquakes may
occur at a fracture or fault zone.
The third type of zone is a converging zone,where two plates come together. There
plates meet,
are two different types of convergence that occur. ln the first instance, as the
This
one plate slides overthe other plate. The lower plate is forced down towards the mantle'
of
the
formation
typeof convergence may result in the occurrence of deep earthquakes or
volcanoes. ln the s"cond type of convergence, the two plates meet, collide, and fold,
creating folded mountain ranges'
Which Way Do You Go?
Look carefully at the four drawings below. With the information you have learned
about plate movements, identify each of the plate zones pictured: convergent (type 1)'
convergent (type 2), spreading, and fracture (fautt)'
c.
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Mark Twain Media, lnc., Publishers
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