igneous rocks Flashcards
1
Q
Form from
A
Magma (molten rock) or lava
2
Q
How does magma form
A
Solid rock in crust / upper mantle partially melts
3
Q
Why does magma rise
A
Magma is less dense. Cools as it rises due to geothermal gradient
4
Q
Volcanic rocks are
A
Mafic and extrusive
5
Q
Hypabyssal rocks are
A
Intermediate and intrusive
6
Q
Plutonic rocks are
A
Felsic and intrusive
7
Q
Aphantic
A
Indistinguishable crystal
8
Q
Vesicular
A
Bubbly cavities
9
Q
Pyroclastic
A
Other minerals inside
10
Q
Porphyritic and phaneritic
A
Viable crystals
11
Q
Pegmatitic
A
Coarse grain, large interlocking crystals
