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An%20Introduction%20to%20the%20Rock%20Cycle

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An Introduction to the Rock Cycle Rocks There are three (3) main types of rocks: Rocks can be igneous, sedimentary, or metamorphic. Igneous Rocks Granite is an ... – PowerPoint PPT presentation

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Title: An%20Introduction%20to%20the%20Rock%20Cycle


1
An Introduction to the Rock Cycle
2
Rocks
  • There are three (3) main types of rocks
  • Rocks can be igneous, sedimentary, or metamorphic.

3
Igneous Rocks
  • Igneous rocks are formed when molten rock (magma)
    cools and solidifies, with or without
    crystallization, either below the surface as
    intrusive rocks or on the surface as extrusive
    (volcanic) rocks.
  • Granite is an igneous rock

4
Sedimentary Rock
  • Sedimentary rock is formed in three main ways
  1. by the deposition of the weathered remains of
    other rocks (known as clastic sedimentary rocks)
  2. by the deposition of the results of biogenic
    activity
  3. by precipitation from solution

Limestone and shale are both types of sedimentary
rock
5
Metamorphic Rock
Slate is a type of metamorphic rock
  • Metamorphic rock is the result of the
    transformation of a pre-existing rock type.
  • Metamorphic means "change in form.
  • Heat and Pressure physically and chemically

6
The Rock Cycle
7
Weathering
  • Weathering is the process of decomposition and/or
    disintegration of rocks, soils and their minerals
    through natural, chemical, and biological
    processes.

8
Erosion
  • Erosion is the displacement of solids (soil, mud,
    rock, and other particles) because of wind,
    water, ice, gravity, or living organisms.
  • Deforestation, overgrazing, and road or trail
    building are human activities that can lead to
    erosion.

9
physical weathering
  • Frost heaving
  • Frost wedging
  • Frost heave is the result of pressure created
    from a combination of freezing temperatures and
    soil defrosting. The fluctuating freezing and
    thawing conditions heave, or lift, the soil,
    which is often characterized by deep cracking of
    the soil. Plants may be uprooted from the ground
    as well.
  • Frost wedging is caused by the repeated
    freeze-thaw cycle of water in extreme climates.
  • Most rocks have small cracks in them, called
    joints. When it rains, rainwater seeps into these
    joints. As the day cools and temperatures at
    night drop below freezing, the water inside the
    joints freezes.
  • As water freezes into ice, it expands.
  • The expanding ice places pressure on the joints
    in the rock. Finally, when the pressure is too
    much, the joint expands. In some cases, the rock
    will split, though this usually happens after
    repeated freeze and thaws. As new water is added
    during the warmer days, more ice is created at
    night, wedging the joints apart further.

10
physical weathering
  • Plant roots
  • Friction and impact
  • The roots of large plants can penetrate the rocky
    soil and break it apart.
  • Constant exposure to friction and impact can
    change the formation of the rocks and cause them
    to break off.

11
physical weathering
  • Animals
  • Temperature changes
  • Animals that burrow into rocks can cause
    weathering.
  • The changing temperatures can alter landscapes by
    causing the soil to freeze or burn.
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