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Ch 1A: Plate Tectonics Study Guide
Name ______________________
Date _____________ Block______
Please use the following ??? ALONG w/all other notes and quizzes to study for test!
1) German scientist, _____________ _________________ proposed the hypothesis of
________________ _____________. 3 things that provided evidence for this are 1)
2)
3)
2) The mapping of the sea-floor helped develop the theory of ____________ ______________, which
states that along spreading centers in the sea floor, ____________rises through cracks, then
____________, and forms new crust that builds up ________ - ___________ _______________,
where the oceanic plates sink into the _____________________. The 3 motions that move Earth’s
huge tectonic plates are 1)
2)
3)
3) A plate boundary is where ____ plates move together. A __________________ boundary occurs
where plates MOVE APART. Most of these boundaries are found in the ____________. A
_______________boundary occurs where plates push together. A ___________ boundary occurs
where 2 plates scrape past each other.
4) Sea-floor spreads apart at ___________________ boundaries. _______-___________ ___________
& ___________ valleys occur at divergent boundaries. Mid-ocean ridges are the longest _________
chains on Earth. The largest mid-ocean ridge is the _______-________________ _______ which runs
about _________ miles through the _________________ Ocean. Most mid-ocean ridges contain a
_________ ____________ along their center.
5) Magma rising through cracked, thinned curst forms ______________. If the ___________
_____________ continues to widen, the thinned valley floor sinks _________ _____________ &
water from nearby oceans or rivers may fill the valley and form a _____________ or ____________.
6) A ______ ____________ can provide a fixed point for measuring the speed & direction of plate
movements because it generally stays in one place where the magma rises in a plume from the
mantle.
7) Tectonic plates push together at _______________ boundaries. There are 3 types of these
boundaries. A) _____________ --____________ ____________ occur where 2 continental plates
collide, crumpling & _________ rock between them. If rocks push high enough, they form
_______________. B) _______________ -- ______________ _______________ occur when 2
oceanic plates collide & the older, more ___________ plate SINKS beneath the top plate, forming
___________ -__________ trenches & ___________________ ________. C) _______________ -_____________ _______________ occur where an oceanic plate SINKS beneath a continental plate,
forming a ____________ - ___________ trench & volcanic _______________ _______________.
8) 2 plates move past each other in opposite directions at __________________ boundaries. NO crust
is _______________ or _______________ at this boundary. These occur on the sea floor & land.