Sedimentary Rock

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Sedimentary Rock

• Sedimentary rock is rock that is formed from the
  accumulation and consolidation of sediments
  (weathered particles of other rocks).
• Lithification is the process by which sediments
  become rock.
• Ex sandstone, shale, conglomerate

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Compression

• Compression occurs as the pressure created by
  water and overlying sediments becomes great
  enough to force particles of sediment close
  together, drive out any water, and compact the
  sediments into rock.
• A good example is shale.

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Shales
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Cementation

• Cementation occurs as the addition of minerals,
  such as silica, lime, or iron oxide, tends to
  glue rock particles together to form solid
  rock.
• Examples are sandstone and conglomerate, which
  are composed of particles of sand, pebbles and
  small rocks.

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Sedimentary Rocks
Conglomerate
Sandstone
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Formation by Chemical Process

• Some sedimentary rocks form as the result of
  chemical processes such as evaporation and
  precipitation.
• Rocks formed by the evaporation of water are
  called evaporites.
• Examples are limestone, rock salt and rock gypsum.

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Examples of Sedimentary Rocks Formed by Chemical
Processes
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Formation by Biological Processes

• Some sedimentary rocks form as a result of
  processes acting on the remains of once living
  organisms.
• Coal is formed from the compression of dead
  plants.
• Limestone is formed from the remaining shells of
  dead sea-life.

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Fossils

• Sedimentary rocks also form and contain remains
  or impressions of plants and animals. These
  impressions are called fossils.

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Fossils
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More Fossils
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3 Kinds of Sedimentary Rocks

• Clastic sedimentary rocks form from the
  compaction and cementation of fragments of other
  rocks.
• Chemical sedimentary rocks form from mineral
  grains that precipitate out by evaporation or
  other chemical action.
• Organic sedimentary rocks form from the remains
  of plants and animals.

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Properties of Sedimentary Rocks

• Rocks may have one or all of these properties at
  the same time
• Discrete layers
• Fragmental particles
• Organic composition
• Range of particle sizes, or
• Predominance of one particle size.

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Sedimentary Samples
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Metamorphic Rock

• Any kind of rock can become a metamorphic rock.
• Metamorphic rock is rock produced by morphism
• Morphism means to change, so these rocks are
  formed by the transformation of preexisting rocks
  into distinct new rocks.
• Metamorphic rocks form as a result of the
  recrystalization of unmelted material under
  conditions of extremely high temperature and
  pressure over long periods of time.

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Classification of Metamorphic Rocks

• Texture refers to the appearance and mineral
  arrangement of metamorphic rocks.
• Foliated rocks have minerals that pressure has
  aligned into layers that are easy to split.
• Banding occurs when there are thin layers of
  alternating minerals.
• Metamorphic rocks are in many ways similar to
  their parent material.

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How Does Morphism Occur?

• Metamorphic rocks form as a result of
• High temperatures
• High pressures
• Combination of both
• BUT without the rock melting in the process.

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Types of Metamorphism

• Contact Metamorphism occurs when molten rock
  comes in contact with surrounding rocks.
• The heat from the magma alters the rock in
  contact with it.
• Regional Metamorphism accounts for the greatest
  amount of metamorphism and occurs when large
  areas of rock are under intense heat and pressure.

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Metamorphism
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Metamorphic Rocks
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Metamorphic Rocks
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What is the Rock Cycle?

• The rock cycle is a theory relating to various
  rock forming processes of the common rock types

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The Rock Cycle
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Rock Cycle Transition Zones

• The process that creates a transition zone
  between rock type is contact metamorphism

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