Download 3.5 * Sedimentary Rocks

3.5 – Sedimentary Rocks
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Essential Questions:
1.
2.
3.
How Do Sedimentary Rocks Form?
What Are the Three Major Types of Sedimentary Rocks?
How Are Sedimentary Rocks Used?
How Do Sedimentary Rocks Form?
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Most sedimentary
rocks are formed
through a sequence of
processes: weathering,
erosion, deposition,
compaction, and
cementation.
How Do Sedimentary Rocks Form?
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Sediment is small, solid pieces of material that
come from rocks or living things.
How Do Sedimentary Rocks Form?
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Weathering is the breaking up of rock on Earth’s
surface through freezing and thawing, plant roots,
acid, or other forces.
How Do Sedimentary Rocks Form?
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Erosion is the movement of these pieces by wind,
water, gravity, or ice (glaciers) from one place to
another.
How Do Sedimentary Rocks Form?
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Deposition is the process by which sediments settle
out the water or wind carrying it.
How Do Sedimentary Rocks Form?
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After many layers of sediments have been laid
down squeezing older sediments together, the older
rocks become compacted.
How Do Sedimentary Rocks Form?
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While compaction is taking place, some minerals in
the rock slowly dissolve in the water. Cementation is
the process in which dissolved minerals crystallize
and glue particles of sediment together.
What Are the Three Major Types of
Sedimentary Rocks?
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Different processes form the three different types
of sedimentary rocks.
 Clastic
Rocks
 Organic Rocks
 Chemical Rocks
Clastic Rocks
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Formed when rock fragments are squeezed together.
 Microscopic
 Clastic
to boulder-sized.
rocks are classified by fragment size.
Organic Rocks
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Formed from the remains of once living things.
 Limestone
and Coal
Chemical Rocks
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Formed when minerals
dissolved in a water
solution crystallize or
when shallow sea or
lakes evaporate.
 Halite
(Rock Salt)
Halite – Rock Salt
How Are Sedimentary Rocks Used?
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Throughout history
sedimentary rocks
have been used for
tools and building
materials.
 Sandstone
buildings
and monuments.
 Flint tools and
weapons.