Chapter 2 Rocks
Rock- Naturally occurring solid mixture made of minerals and organic matter. Rock type is determined by how it is formed
Three types of Rock
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________________________- formed from magma
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_____________________________________ formed as a by-product of weathering, erosion, decomposition
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__________________________________- formed from changes in temperature and/or pressure
Rock Cycle
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The continual process by which ____________ ______________ forms from _______________ ___________________
Ways to tell which rocks are which:
Igneous:
Intrusive igneous rocks
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_________________ ___________________________ cemented together.
Crystallize below Earth's surface
___________________ ____________________ that occurs there allows large crystals to form.
Extrusive igneous rocks
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_______________ ___________________ some are not visible
________________________ surface
May have ___________________ _______________________
May look like _____________________________
erupt onto the surface where they cool quickly
Sedimentary:
Clastic sedimentary rocks
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Fragments of rocks _________________________________ together
Can be course grained like “conglomerate” or fine grained like shale
Chemical
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_______________________________ ___________________________ leaving cemented crystals behind
Organic
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May contain _______________________________
Metamorphic:
Foliated
____________________________________-
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crystals seem to go in the same direction
Non-foliated
No bands
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Can have a _____________________________ appearance
Texture and composition give clues as to how rocks are formed, and are used to classify rocks
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__________________________ – the type of material a rock contains
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______________________ – the size, shape and arrangement of the minerals/particles that make up a rock.
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Cooling rate affects texture:
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Rocks that ____________________ ________________ have very ___________________
____________________________, air pockets, and can be glassy
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Rocks that ____________________ ________________ have _______________ crystals
Igneous Rocks2 types depending on how formed
1) Extrusive
2) Intrusive
Extrusive rocks- formed by cooling ______________________________ so cools quickly
Texture:
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_________________________ (obsidian)
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______________________________(pumice)
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_____________ - ________________ (basalt)
Intrusive rocks- formed by cooling magma so cools slowly
Texture:
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____________________ - ____________________ (granite)
Sedimentary Rocks
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Formed from the ______________________, _______________________, ________________________ and
_____________________________ of minerals and other materials
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Occurs at or ____________________ the earth’s _____________________________
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Three types:
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_______________(rock fragments): made from fragments of rocks cemented together
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___________________________: formed from dissolved minerals that have crystallized out of solution
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_________________________: made from previously living organisms
Five Agents of Erosion
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Gravity (Mass wasting)
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______________________
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Running water
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_________________________
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Waves
Deposition, compaction, cementation:
Metamorphic Rocks
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Formed by tremendous ___________________ & ________________________, and chemical reactions inside
the crust.
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Formed from all three rock types.
Types of Metamorphic Rock
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Foliated (bands or layers)
Ex: schist, slate, gneiss
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Non-Foliated (no bands or layers)
Ex: marble and quartzite
Pressure determines if metamorphic rocks will be foliated or non-foliated
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If there is ____________________ __________________________, rocks will be _______________________
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If there is ______________________ _____________________________, rocks will be non-foliated