Section 13-1 ReviewSection 13-1 Review

Page #324:1-8Page #324:1-8

#1#1Describe three conditions that affect Describe three conditions that affect

whether magma forms.whether magma forms.

Magma forms when . . . Magma forms when . . . • the temperature of the rock rises above the the temperature of the rock rises above the

melting point of the minerals that compose it, melting point of the minerals that compose it,

• the pressure of the rock decreases faster than its the pressure of the rock decreases faster than its temperature does, temperature does,

• when it is mixed with fluids that decrease its when it is mixed with fluids that decrease its melting point.melting point.

#2#2

Explain how magma reaches Explain how magma reaches Earth’s surface.Earth’s surface.

Magma reaches Earth’s surface by Magma reaches Earth’s surface by rising through less dense rock in the rising through less dense rock in the crust.crust.

#3#3

Compare magma with lava.Compare magma with lava.

Magma is melted rock beneath Earth’s Magma is melted rock beneath Earth’s surface; lava is magma that erupts surface; lava is magma that erupts onto Earth’s surfaceonto Earth’s surface

MagmaMagma LavaLava

#4#4

Describe how subduction produces Describe how subduction produces magma.magma.

The denser, subducted plate releases The denser, subducted plate releases fluids to the surrounding crust and fluids to the surrounding crust and mantle materials, thus lowering their mantle materials, thus lowering their melting points and causing magma melting points and causing magma to form.to form.

Subduction creating MagmaSubduction creating Magma

#5#5

Identify three tectonic settings Identify three tectonic settings

where volcanoes commonly where volcanoes commonly

occur.occur.

subduction zonessubduction zones

mid-ocean ridgesmid-ocean ridges

hot spotshot spots

Subduction ZoneSubduction Zone

Mid-Ocean RidgeMid-Ocean Ridge

#6#6

Summarize the formation of hot Summarize the formation of hot

spots.spots.

The hot spot lies above a column of The hot spot lies above a column of solid, hot material from the mantle. solid, hot material from the mantle. When the mantle material spreads When the mantle material spreads out at the top of the plume, its out at the top of the plume, its pressure drops and the rock melts. pressure drops and the rock melts. The resulting magma forms The resulting magma forms volcanoes at the hot spot.volcanoes at the hot spot.

Hot SpotHot Spot

#7#7

Describe how the presence of ocean water in Describe how the presence of ocean water in crustal rocks might affect formation of crustal rocks might affect formation of magmamagma ..

Ocean water in ocean rock can lower the melting Ocean water in ocean rock can lower the melting point of the rock and aid the formation of point of the rock and aid the formation of magma. magma.

#8#8Yellowstone National Park in Yellowstone National Park in Wyoming is far from any plate boundary. Wyoming is far from any plate boundary. How would you explain the volcanic How would you explain the volcanic activity in the park?activity in the park?

The volcanic activity in Yellowstone The volcanic activity in Yellowstone National Park would be due to mantle National Park would be due to mantle plume that cause a hot spot within plume that cause a hot spot within the continental crust.the continental crust.

Yellowstone Magma ChamberYellowstone Magma Chamber

Yellowstone Volcano HistoryYellowstone Volcano History

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