Section 13-1 Review. Page #324:1-8. #1. Describe three conditions that affect whether magma forms. Magma forms when. the temperature of the rock rises above the melting point of the minerals that compose it,. the pressure of the rock decreases faster than its temperature does,.
Describe three conditions that affect
whether magma forms.
Magma forms when . . .
Explain how magma reaches Earth’s surface.
Magma reaches Earth’s surface because the rising magma is less dense than the surrounding rock of the crust.
Compare magma with lava.
Magma is melted rock beneath Earth’s surface; lava is magma that erupts onto Earth’s surface
Describe how subduction produces magma.
The denser, subducted plate releases fluids to the surrounding crust and mantle materials, thus lowering their melting points and causing magma to form.
Identify three tectonic settings
where volcanoes commonly
Summarize the formation of hot
The hot spot lies above a column of solid, hot material from the mantle. When the mantle material spreads out at the top of the plume, its pressure drops and the rock melts. The resulting magma forms volcanoes at the hot spot.
Describe how the presence of ocean water in crustal rocks might affect formation of magma.
Ocean water in ocean rock can lower the melting point of the rock and aid the formation of magma.
Yellowstone National Park in
Wyoming is far from any plate boundary.
How would you explain the volcanic
activity in the park?
The volcanic activity in Yellowstone National Park would be due to mantle plume that cause a hot spot within the continental crust.