Types of Rock

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Types of Rock
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What are Rocks?

• A rock is a naturally occurring solid mixture of
  one or more minerals, or organic matter
• Rocks are classified by how they are formed,
  their composition, texture and color
• Rocks change over time through the rock cycle

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Igneous Rocks

• Igneous rock begins as magma or lava.
• Magma can form
• When rock is heated
• When pressure is released
• When rock changes composition
• Magma/lava cools igneous rock

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Igneous Rocks

• Coarse-grained takes longer to cool, giving
  mineral crystals more time to grow
• Fine-grained cools quickly with little to no
  crystals

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Igneous Rocks
Coarse-Grained
Fine-Grained
Granite
Rhyolite
Gabbro
Basalt
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Igneous Rocks

• Intrusive Rocks magma pushes into surrounding
  rock below the Earths surface
• Extrusive Rocks forms when magma erupts onto the
  Earths surface (lava), cools quickly with very
  small or no crystals formed

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Igneous Rocks

• Obsidian is a dark-colored volcanic glass that
  forms from the very rapid cooling of molten rock
  material. It cool so rapidly that no minerals
  form.

Is it fine-grained or coarse-grained? Is this
rock Intrusive or Extrusive?
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Sedimentary Rocks

• Sediments are moved from one place to another
• Particles of rocks, shells, bones, leaves, stems
  and other once living things
• Sediments are eroded
• Water, wind or ice
• Deposited in layers, with the older ones on the
  bottom.
• Settled out from water or wind
• The layers become compacted
• Pressed together
• And cemented together
• Dissolved minerals crystallize and glue particles
  together

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Sedimentary Rock

• Sedimentary Rocks are formed at or near the
  Earths surface
• No heat and pressure involved
• Strata layers of rock
• Stratification the process in which sedimentary
  rocks are arranged in layers

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Sedimentary Rock

• Clastic made of fragments of rock cemented
  together with calcite or quartz

Breccia
Conglomerate
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Sedimentary Rock

• Organic remains of plants and animals are
  deposited in think layers

Coal
Coquina
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Metamorphic Rock

• Meaning to change shape
• Changes with temperature and pressure, but
  remains solid
• Usually takes place deep in the Earth

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Metamorphic Rocks

• Contact Metamorphism heated by nearby magma
• Increased temperature changes the composition of
  the rock, minerals are changed into new minerals

Hornfels
http//www.windows.ucar.edu/tour/link/earth/geolo
gy/meta_contact.htmleduh ighfrt
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Metamorphic Rocks

• Regional Metamorphism pressure builds up in
  rocks that are deep within the Earth
• Large pieces of the Earths crust collide and the
  rock is deformed and chemically changed by heat
  and pressure

http//www.windows.ucar.edu/tour/link/earth/geolo
gy/meta_regional.htmleduhighfrt
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Metamorphic Rock

• Foliated - contain aligned grains of flat
  minerals

Gneiss
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Metamorphic Rock

• Non-Foliated mineral grains are not arranged in
  plains or bands

Marble
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Metamorphic Rock

• Determine if the following rock samples are
  foliated or non-foliated

Quartzite
Amphibolite
Phyllite
Foliated
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How are rocks used?

• Igneous Rocks
• Granite obsidian pumice
• Countertops sharp tools abrasive
• Sedimentary Rocks
• Sandstone limestone
• Building materials making steel
• Metamorphic Rocks
• Marble, slate
• Building materials, statues, flooring, tiles,
  countertops, chalkboards, pool tables, roofing

Write down at least two from each category.