Geology 3
Terms
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- Magma crystallization
- -less dense than solid rock so materials rise -higher levels are cooler so crystallization tends to occur as magma body rises. -pressure decreases also though and tends to slow or delay crystallization. -Form and melt )Ferro first then non-ferro) Rock type is determined by cooling history and magma composition.
- Plutonic
- (Intrusive) Crystallize slowly at depths and are visible to the naked eye.
- Volcanic
- (Extrusive) Quickly cooled magma on the Earth\'s surface. Minerals cannot be seen by the eye.
- Silica content (Igneous rocks)
- Felsic igneous rock (highest content)--> intermediate--> mafic--> ultramafic (mantle rocks).
- Sedimentary Rocks
- -cover 75% of crust but 7% of content -tells use the composition of ancient topographies, climate, ocean condition and life forms.
- Sedimentary formations:
- Sediment: Loose (rock particles) or dissolved ions in solution (water) reforming. OR Lithification: process by which loose sediment particles are transformed into solid rock. Compact versus cementation (Precipitation of \"glues\")
- 3 Classes of Sedimentary Rocks
- Clastic: formed from weathered bits of pre-existing rocks. ⬢ Chemical: formed by chemical reaction ⬢ Biochemical: formed by biologically-mediated precipitation of minerals from solution.