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5 criteria to be classified as minerals
- Naturally occurring
- Solid substance
- Orderly crystalline structure
- Generally Inorganic
-Well defined chemical composition
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Physical properties
-Luster
- Ability to transmit light
-Color
- Streak
- Tenacity
-Hardness
- Cleavage
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Silicates
- they all contain oxygen and silicon atoms.
--carry silicon-oxygen tetrahedron
-some form from molten rock as it cools, others formed at earths surfaces as weather erodes.
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non-silicates
- only make 8 percent of earths crust.
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magma
-is melting that occurs primarily within earth's crust and upper mantle
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Lava
- its magma tha reaches earth's surface.
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(Igneous) Felsic- Granitic
Quartz, potassium feldspar
- Coarsed grained: granite
- Fine grained: Rhyolite
- Glassy: Obsidian and Pumice
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(igneous) Intermediate- Andesitic
Amphibole, sodium and calcium rich
- Coarsed grained: Diorite
- Fine-grained: Andesite
- Glassy: Obsidian and Pumice
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(igneous) Mafic- Basaltic
Pyroxene, Calcium-rich
- Coarse-grained: Gabbro
- Fine grained: Basalt
- Glassy- Obsidian
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(igneous) Ultramafic
Olivine and pyroxene
- Coarse-grained: Peridotite
- Fine grained: Komatiite
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Chemical weathering
- water is the most important agent of chemical weathering
- Carbon dioxide is another chemical weathering.
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Mechanical weathering
this process breaks down small pieces of the object but retains its properties.
- Frost wedging
-Sheeting
- Biological activity
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Detrital sedimentary rocks
- they form from solid products of weathering
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Chemical sedimentary rocks
- derived from solutions that are carried to the lakes and seas.
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Lithification
refers to processes by which sediments are transformed into solid sedimentary rocks.
Compaction: most common process, overlying material compresses the deeper sediments.
Cementation: the cementing materials are carried in solution by water percolating through its pores.
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Sedimentary rock features
- some may contain fossils
- Strata and beds are the most common trait
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(metamorphic triggers) Heat
- It results in recrystallization of existing minerals and formation of new mineral.
- Rocks can increase their tempertaure by having magma touching them, calling them baked rock.
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(metamorphic triggers) Pressure
- temperature increases the further one goes down as pressure as well.
- confining pressure causes the spaces between minerals grains to close.
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(metamorphic triggers) Chemical
- they aid in recrystallization
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Common foliated texture
Slate, schist, and gneiss
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common non-foliated texture
Marble and quartzite
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Divergent boundaries
is a boundary where 2 plates are moving away from one another
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Convergent boundary
two plates in which they come together
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Transform fault boundary
two plates rub against one another in a sideways motion
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calculate rate of plate motion
cm/ year
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