15 Questions
What is the main reason that magma tends to rise from within the Earth?
The liquid rock is less dense than the surrounding solid rock
Why can magma vary in composition?
Because it forms when rocks melt and rocks are made of different minerals with different melting points
What term is used to refer to magma when it reaches the surface of the Earth?
Lava
What is a common misconception when people refer to magma?
That it means liquid rock in general
How is magma formed?
When rocks melt as they are made of different minerals with different melting points
What is the relationship between magma and solid materials according to the text?
Magma is a combination of liquid, solid, and semi-liquid materials.
Where is magma typically located within the Earth?
In the upper mantle and lithosphere
What are some regions where magma accumulates according to the text?
At the boundaries of lithosphere and asthenosphere
What processes allow solid rock to melt within the upper mantle and crust?
Decompression of rising heat and material from mantle plumes or convection currents
What happens as material rising from convection currents experiences a decrease in pressure?
The particles spread out and cause the material to melt due to decompression.
What contributes to the melting of crust material at subduction zones?
Rising temperatures due to the sinking of one tectonic plate beneath another
What is a characteristic of felsic magma compared to mafic magma?
More viscous and resistant to flow
What happens when magma reaches the Earth's surface?
It solidifies back into rock
What makes magmas formed from mantle plumes different from those formed from melting crust material?
They have higher silica content
What is the role of water in the formation of magma at subduction zones?
It acts as a catalyst for the breakdown of minerals into magma
This quiz explores the formation and characteristics of magma, the molten rock found beneath the Earth's surface. It covers the sources of heat that lead to magma formation and how it behaves when it reaches the Earth's surface.
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