• Deposition – process by which
wind, water, ice, and gravity
leave eroded sediments in new
locations
• What types of landforms are
caused by deposition?
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•
•
•
•
Deltas
Sandbars
Islands
Sand Dunes
Alluvial Fans
Deltas
• Deltas occur at the end
of a river.
• The end of a river is
usually a large body of
water such as a lake,
bay, ocean or gulf.
Mississippi River Delta
Notice the
sediment that
is flowing
down the river
and out into the
Gulf of Mexico.
This sediment
is building the
delta.
Nile River Delta
• Typical delta shape - like
a triangle.
Gulf Coast Plains and Marshes
• Wave action, a cause of
weathering, erosion and
deposition, is constant
along the Texas
Coastline.
• Sediments are
weathered and eroded
along beaches and
carried out into the
ocean to form sand bars
and islands.
Mustang Island
• Mustang Island in Port
Aransas, Texas.
• How was this formed?
Sandbar
• Sandbars happen on
the sides of the river.
• As the river slows
down, it allows the
heavier sediment to
drop out of the water
and deposits it in the
sandbar.
Sandbars
• Sandbars can be large
and long lasting.
• This one was named in
1898 Whitaker’s Point
and has stayed in place
since then.
Sand Dunes
• Wind erosion deposits
the sand.
Waves and Deposition
• http://app.discoveryeducation.com/player/vie
w/assetGuid/B0A92767-4528-41D4-BD06C8076220E272
Alluvial Fan
• This landform is shaped
like a delta.
• It happens when
rainwater from the
mountains runs through
a canyon.
• The deposits are left in
the valley rather than
the ocean.
Alluvial Fan
• This alluvial fan is in
Death Valley, California.
• Notice the road that has
been built around it.
Death Valley, Ca.
• Death Valley, Ca. is a
valley with no outlet.
• The water that comes
into the valley can not
get out.
• It just evaporates
leaving white deposits
of minerals.
Death Valley
• The white deposits are
sodium borate.
• This chemical poisons
the small ponds that are
formed and so no
animals or plants can
live there.
• Which of the following landforms is not
formed by deposition?
• alluvial fan
• delta
• river valley
• Which of the following landforms is found at
the end of a river where it enters a large body
of water?
• alluvial fan
• delta
• sandbar
• How can you tell the difference between a
delta and an alluvial fan?
• An alluvial fan is at the bottom of a mountain
• A delta is at the bottom of a mountain
• Deltas only occur in deserts
• Why do sandbars for in the curve of a river?
• The river speed up and drops the sand
• The river loses speed and drops the sand
• There is a pile of rocks that catches the sand
• Which of these processes is in the correct
order?
• weathering, deposition, erosion
• deposition, weathering, erosion
• weathering, erosion, deposition
• Explain what would happen over
time to a rock cliff on the ocean’s
edge. Describe the whole
process and what the result
might be.