Plate Tectonics - Part C
- Volcanoes and Plate tectonics
Part C Assessment
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Copy and Complete Section Assessment p. 501 of text
• Writing in Science Travel Brochure
– Is to be completed with a partner
– Use your answers to the assessment above
– and turned in for a Quiz grade on _______________________________________
Volcanoes and Plate Tectonics
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A _________________________________ is a weak spot in Earth’s crust where molten material or
magma comes to the surface.
Volcanoes and Plate Tectonics
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___________________________ is a molten mixture of rock-forming substances, gases, and water from
the mantle.
Volcanoes and Plate Tectonics (cont.)
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When magma comes to the surface, it is called ___________________________.
After lava has cooled, it forms solid rock.
Lava released during volcanic activity builds up on ________________________________.
Volcanoes and Plate Boundaries (cont.)
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There are more than ____________________volcanoes on land and many more beneath the sea.
Volcanoes and Plate Boundaries (cont.)
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Most volcanoes occur in ___________________ that extend across continents and oceans.
(see p. 499)
Volcanoes and Plate Boundaries (cont.)
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One major volcanic belt is the ______________________________________, formed by the many
volcanoes that rim the Pacific Ocean.
Volcanoes and Plate Boundaries (cont.)
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Volcanic belts form along the ______________________________________of Earth’s plates.
At plate boundaries, huge pieces of crust _______________________________ (pull apart) or
________________________________ (push together).
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As a result, the crust often _________________________, allowing magma to reach the surface.
Volcanoes and Plate Boundaries (cont.)
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Most volcanoes form along diverging plate boundaries such as _______________________ –orAlong converging plate boundaries where ________________________________ takes place.
Volcanoes and Plate Boundaries -Divergent boundaries
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Volcanoes form along mid-ocean ridges, which mark diverging plate boundaries.
Ridges are ________________________________________________________________ .
Along the rift valley lava pours out of cracks in the ocean floor, gradually building ___________________
__________________________.
Volcanoes and Plate Boundaries -Divergent boundaries (cont.)
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Volcanoes also form along diverging plate boundaries ________________________.
For example, there are several large volcanoes along the ____________________________________in
East Africa.
Volcanoes and Plate Boundaries -Convergent boundaries
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Many volcanoes form near converging plate boundaries where _________________________________
__________________________________
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Volcanoes may form where ________________________________________________ collide –orWhere an oceanic plate collides with a _______________________________ plate.
(see p. 500)
-Convergent boundaries -When Two Oceanic Plates collide
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Many volcanoes occur where _________________________________________________
Through __________________________________, the older, denser plate sinks beneath a deep ocean
trench into the mantle.
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Some of the rock above the subducting plate melts and forms __________________________
-Convergent boundaries -When Two Oceanic Plates collide (cont.)
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Because the magma is ___________________ than the surrounding rock, it ____________________
toward the surface.
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Eventually, the magma breaks through the ocean floor, creating volcanoes
The resulting volcanoes create a string of islands called an ______________________________.
-Convergent boundaries -When Two Oceanic Plates collide (cont.)
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The curve of an island arc echoes the curve of its __________________________________________.
Major island arcs include Japan, New Zealand, Indonesia, the Philippines, the Aleutians and the
Caribbean islands
-Convergent boundaries -When Oceanic Plates Collide into Continental Plates
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Volcanoes also occur where an _______________________________________________________
______________________________________________________.
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Collisions of this type produced the volcanoes of the Andes and Peruvian Mountains in South America
and the volcanoes of the Pacific Northwest in the United States
Hot Spot Volcanoes
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Some volcanoes result from ‘hot spots’ in Earth’s mantle.
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A _________________________________ is an area where material from deep within the mantle rises
and then melts forming magma
Hot Spot Volcanoes (cont.)
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A volcano forms above a hot spot when magma _________________ through the crust and reaches the
surface.
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Some hot spot volcanoes lie in the _______________________________ far from any plate boundaries
Others can occur on or near plate ___________________________________
Hot Spot Volcanoes (cont.)
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A Hot Spot in the ocean floor can gradually form a ____________________of volcanic mountains
For example the Hawaiian Islands formed one by one over millions of years as the pacific plate drifted over a
hot spot.
Hot Spot Volcanoes (cont.)
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Hot spots can also form under ________________________________.
Yellowstone National Park in Wyoming marks a hot spot under the north American plate
Can you describe all the features found in this diagram?