c. Classify rocks by their process of formation.

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Sedimentary Rock

• c. Classify rocks by their process of formation.
• d. Describe processes that change rocks and the
  surface of the earth.

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Sedimentary Rock

• Formed from particles of sediment deposited by
  wind and water.
• Sediment is small pieces of solid materials that
  come from rocks or living things.

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Stratification

• Yes, all these rocks are layered or stratified.

4
Weathering

• The process by which exposed rock is broken down
  into small pieces by the elements of nature
  (wind, rain, ice, chemical actions, plants, etc.)

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Origins of Sedimentary Rock

• Wind, water, ice, sunlight, and gravity all cause
  rock to physically weather into fragments.
• Through erosion, these rock and mineral
  fragments, called sediment, are moved from one
  place to another.
• The sediment is deposited in layers, and
  eventually newer layers cover the older layers.

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Erosion

• Occurs when water or wind loosens rock and soil
  and carries it away.

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Deposition

• The process by which the sediment settles out of
  the water or air carrying it.
• Sediment is deposited when the wind or water
  slows down.

8
Compaction

• As the sediments settle they will loosely fit on
  top of each other.
• As the years go by, more and more sediment is
  added.
• The bottom layers get compacted by the weight of
  the layers above them.

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Cementation

• While compaction is going on, minerals in the
  rock slowly dissolve.
• The dissolved minerals seep into the spaces
  between the compacted sediment.
• They crystallize and glue the sediments together.

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Lithification

• The process by which sediment becomes sedimentary
  rock.
• From Green word lithos, which means rock.
• Erosion
• Deposition
• Compaction

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Types of Sedimentary Rock

• Clastic formed when rock fragments are squeezed
  together.
• Organic (biological) formed from the remains of
  living things.
• Chemical formed when dissolved minerals
  crystallize.

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Conglomerate and Breccia

• Formed from a mixture of rock fragments of
  different sizes.
• Conglomerate has rounded edges.
• Breccia has larger fragments with sharp edges

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Sandstone

• Formed from sand on beaches, ocean floors, river
  beds, and deserts.
• Mainly quartz.

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Shale

• Clastic rock from from tiny particles of clay.
• Water deposits tiny clay particles in thin
  layers.
• Feels smooth and splits easily into flat sheets.

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Organic Sedimentary Rock

• Formed from the remains of plants and animals
  that were deposited in thick layers.
• Also called biological rock.

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Coal

• Formed from the remains of ancient swamps.
• As layer upon layer of dead plants built up, the
  bottom layers were compacted into coal.
• Stored chemical energy from

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Limestone

• Formed from the shells of ancient sea animals and
  plants.
• Shells fall to the bottom of the ocean in layers,
  some 100s of meters thick.
• Compaction creates limestone.

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Chalk

• Formed from the shells of ancient sea life.
• Creates layers 100s of feet thick.
• White Cliffs of Dover

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Chemical Sedimentary Rock

• Formed when water with dissolved minerals
  evaporates.
• The left behind minerals will crystallize.

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Halite

• Rock Salt
• Formed from seas and oceans that dried up.
• The salt forms large crystals.

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Gypsum

• Made from calcium deposits.
• Used to make sheet rock for homes.