Test 2 (Lectures 4-8) Pt. 1 Flashcards
(51 cards)
Where is lava found?
Above/on the Earth’s surface
Where is magma found?
Beneath the Earth’s surface
What do extrusive magma create?
Lava flows and pyroclastic deposits
Where do intrusive rocks form?
They form below the ground
The extrusive realm is __ the ground
Above
The intrusive realm is ___ the ground
Below
Many volcanoes are part of the ___ zone volcanism
Subduction
Where do igneous rocks come from?
They come from lava or magma
Where do most igneous activities occur in?
They occur along the mid-ocean ridge. And most occur below the sea level.
Magma is a mixture of…?
Melts
How is magma formed?
When water melts the mantle it forms magma
What does rift-related lithospheric thinning cause?
It causes decompressional melting of the asthenosphere
When heat transfer melts the crust what does the process create?
It creates felsic magmas
What kind of activity does mantle plume hot spots generate?
They generate igneous activity
What can hot-spot volcanoes do?
They can track igneous activity
What does the acronym LIPs stand for?
Large Igneous Provinces
What are LIPs?
Large areas of mafic melt that appear periodically over geologic time
What can LIPs result from?
They can result from mantle plumes at the base of the lithosphere that create huge volumes of low-viscosity mafic magma
What are some ways to melt the Earth (or the mantle)?
- Get it hot (add heat)
- Decrease pressure
- Add fluids or volatiles
In slide 12 of lecture 5, what is the green line called?
Solidus
In slide 12 of lecture 5, what is the red line called?
Liquidus
Where does decompression melting occur?
They occur at:
- Mantle plumes
- Continental rifts
- Divergent-plate boundaries
In a subduction zone, what volatiles are driven from the oceanic crust and into the asthenosphere?
H20 and CO2
What are the different types of melt?
- Mafic
- Ultramafic
- Felsic
- Intermediate
