Transcript Chapter 5: Rocks

Chapter 5: Rocks
Section 3: Sedimentary Rocks
From Sediment to Rock
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Sediment – small, solid pieces of material that come
from rocks or living things (shells, bones, leaves, stems,
etc)
Sedimentary rocks form when sediment is deposited by
water and wind
Form through a series of processes
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Erosion
Deposition
Compaction
Cementation
Erosion
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The destructive process in which water or wind loosens
and carries away fragments of rock
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Rain
Waves
Ice
Deposition
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Process by which sediment settles out of the water or
wind carrying it
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Ex. If in water, sinks to bottom
Compaction
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Process that presses sediments together
Caused by weight
Layers often remain visible
Cementation
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Process in which dissolved minerals crystallize and glue
particles of sediment together
Dissolved minerals seep into the spaces between
particles and harden
Checkpoint 1
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Describe the process by which sedimentary rocks form.
Checkpoint 1
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Describe the process by which sedimentary rocks form.
Sedimentary rocks form through the process of erosion
(wind or water loosen and carry away fragments of rock),
deposition (sediments settle), compaction (sediments
compress), and cementation (sediments glue together).
Types of Sedimentary Rock
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Clastic Rock – a sedimentary rock that forms when
rock fragments are squeezed together
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Fragments can range in size from clay particles to large
boulders
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Shale – forms from tiny particles of clay
Sandstone – forms from sand (consist of quartz)
Conglomerate – mixture of rock fragments of different sizes with
rounded edges
Breccia – large fragments with sharp edges
Types of Sedimentary Rocks
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Organic Rocks – form when the remains of plants and
animals are deposited in thick layers
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Coal – forms from the remains of swamp plants buried in
water; as layer upon layer of plant remains build up, the weight
of the layers squeezes the decaying plants and over time turns
into coal
Limestone – forms in the ocean from shells and skeletons
made of calcite deposit
Types of Sedimentary Rocks
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Chemical Rocks – form when minerals that are
dissolved in a solution crystallize
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Halite – when seas or lakes evaporate
Some kinds of limestone – calcite crystallizes as water
evaporates
Checkpoint 2
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How are clastic rocks different from organic rocks?
Checkpoint 2
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How are clastic rocks different from organic rocks?
Clastic rocks are formed from broken pieces of other
rocks and organic rocks are formed from the remains of
living things.
Uses of Sedimentary Rocks
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Hard, but can be shaped
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Building materials
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White House built from sandstone
Limestone used in making cement and steel
Tools
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Arrowheads from flint
Checkpoint 3
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What properties of sedimentary rocks make them useful
as tools and building materials.
Checkpoint 3
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What properties of sedimentary rocks make them useful
as tools and building materials.
They are hard and durable, but still soft enough to shape.
Post-less Quiz
1. What is the process in which dissolved minerals
crystallize and glue particles of sediment together?
a. erosion
b. deposition
c. compaction
d. cementation
Post-less Quiz
2. What is a sedimentary rock that forms when rock
fragments are squeezed together?
a. clastic
b. organic
c. chemical
d. igneous
Post-less Quiz
3. What is the destructive process in which water or wind
loosens and carries away fragments of rock?
a. erosion
b. deposition
c. compaction
d. cementation
Post-less Quiz
4. What type of sedimentary rock forms when the remains
of plants and animals are deposited in thick layers?
a. clastic
b. organic
c. chemical
d. igneous
Post-less Quiz
5. What is the process by which sediment settles out of the
water or wind carrying it?
a. erosion
b. deposition
c. compaction
d. cementation