Term
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Definition
naturally occuring
inorganic
solid
specific composition (chemical formula)
crystalline
specific physical properties |
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Term
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Definition
cations & anions
oxides
silicates
alumino silicates
carbonates
sulfides
sulfates
chlorides |
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Term
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Definition
| precipitation from a saturated solution - add seed to saturated solution - acts as template for particles to arrange on to - CONCENTRIC GROWTH (growth in every direction in layers, making rings) |
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Term
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Definition
| cools too quickly for any crystalline structure to form (cooling from hot liquid magma) |
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Term
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Definition
| formed by crystallization of a liquid, produces interlocking grains and zoning |
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Term
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Definition
- form from COOLING MAGMA
- crystal size vs. cooling rates:
- SLOW COOLING: large grains - coarse
- FAST COOLING: small grains - fine
- VERY FAST COOLING: quenched, glass - orderless, non-crystalline |
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Term
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Definition
| subsurface, magma squeezes its way between other rocks to form igneous rocks very slowly |
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Term
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Definition
| surface, lava - pouring out of ground to form igneous rocks quickly, or ash solidifying in sky forming igneous glass |
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Term
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Definition
hardening of sediment in 3 ways:
- compaction (burial)
- dewatering
- cementation (chemical precipitation in pore spaces) |
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Term
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Definition
| sedimentary rocks composed of SOLID PARTICLES (clasts) ERODED from other rocks - NON-INTERLOCKING GRAINS |
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Term
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Definition
sedimentary rocks composed of chemically and/or organically precipitated or accumulated sediment
- LIMESTONE: organic remains - calcite from shells, coral etc.
- COAL: plant remains
- SALT: chemical precipitation in lake or ocean |
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Term
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Definition
the process by which HEAD, PRESSURE, and CHEMICAL REACTIONS deep within the Earth altar the MINERAL CONTENT and/or STRUCTURE of preexisting rock WITHOUT MELTING IT
- ANY type of rock can be metamorphosed (igneous, sedimentary, metamorphic) |
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Term
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Definition
(slate, schist, gneiss)
rocks altered by HEAT and PRESSURE
metamorphic grade - level of metamorphism
becoming stable again:
- recrystallization
- baking
- deformation (stretch, fold)
if GRADE TOO HIGH - melting, starting with minerals with the lowest melting temperature
- IF REALLY TOO HIGH - magma |
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Term
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Definition
1. formation of rock unit (deposition, extrusion, intrusion)
2. metamorphism
3. folding, tilting
4. faulting & fracturing
5. formation of an unconformity |
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Term
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Definition
a surface that:
1. represents significant missing time
2. and had a sedimentary unit, ash, or lava flow laid down on top of it
OR is the current eroded Earth's surface (implies: erosion or period of non-deposition) - river valley that got eroded and now has a new layer of rock on top |
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Term
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Definition
past events always obeyed the laws of math, chemistry and physics like processes today
things happened in the past just like they do today, same rules apply |
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Term
| Fundamental principles of layers |
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Definition
| Superposition, horizontality, continuity, intrusion, crosscutting, derivation, inclusions |
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Term
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Definition
| sediment is always deposited ON TOP of some other sediment or rock that is older - younger ON TOP of older |
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Term
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Definition
sediments are deposited (almost always) as horizontal layers, beds, or strata
if the layers appear inclined it happened after they formed |
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Term
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Definition
| strata found truncated (narrowing down towards the surface) originally extended in all directions until they thinned to nothing or reached the edges of their depositional basin |
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Term
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Definition
| an intrusive igneous rock unit must be younger than the rock it intrudes |
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Term
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Definition
| a fault, erosion surface, or intrusive igneous rock unit is younger than the rock that is cut |
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Term
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Definition
| If part of a rock unit is derived from another rock unit, it must be younger than the original rock |
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Term
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Definition
| parts of an older rock unit enclosed in an igneous rock body are inclusions |
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Term
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Definition
| parts of an older rock unit enclosed in an igneous rock body are inclusions |
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Term
| Geologic Time Scale Hierarchy |
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Definition
- eons
- eras
- periods
- epochs
- stages (ages) |
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