1. ROCKS ROCK Classified on the basis of FORMATION 3 Types Sedimentary
Igneous
Metamorphic
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2. Rocks Composed of Minerals 2 Types
Mixtures
2 Types
Monomineralic
Polymineralic
Of the 4000 minerals, only 8 of them make up 90% of the crust.
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Sedimentary Rocks
Rocks that form from the accumulation of sediments, organic material or chemical precipitates.
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4. Three main types Clastic Chemical/non-clastic Organic
Made from fragments of other rocks
Chemical/non-clastic
Organic
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5. Clastic (also known as fragmental)
Classified on the basis of grain size
Formation-
Compaction (Pressure)
Cementation (glued)
Examples
calcite
silicate
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6. Layers of sediments accumulate Pressure squeezes lower layers
Sediment becomes compacted and cemented into rock
Pressure = Sandstone
Pressure = shale
Pressure = Limestone
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9. Non-clastic (chemical) sedimentary rocks
Formed from evaporation of water
Examples
limestone
Halite
Also known as evaporites
Precipitates also occur
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10. Organic Sedimentary Rocks
Formed from the remains of former living things
Example: coal
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13. Sedimentary Rocks  Why?
Chemical and organic sedimentary rocks identified primarily by composition and texture (grain size)
Sedimentary rocks form relatively close to the Earth’s surface
 Why?
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14. Sedimentary Rocks Why do you think this is so?
All clastic sedimentary rocks are formed in horizontal layers
Why do you think this is so?
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16. Bedding in Sandstone and Shale, Utah

17. Crossbedded Sandstone, Zion Natl. Park, Utah
Crossbedded Sandstone, Zion Natl. Park, Utah. Formed by Sand dunes deposited by wind

18. Graded Bedding

20. Sedimentary Rocks Why not?
Sedimentary rocks sometimes contain fossils
Igneous and metamorphic rocks almost never do
Why not?
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21. Sedimentary Rocks
Lake and ocean environments produce different sedimentary rocks
Examples:
Limestone
Forms in oceans
Sandstone
Forms in water near land
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23.  Use your ESRT to answer the following questions.
What is the composition of rock salt?
What is the size range of the grains in sandstone?
Draw the map symbol of shale
Which is made of rounded fragments, conglomerate or breccia?
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