FOCUSES ON EROSION AND DEPOSITION BASIC CONCEPT

1. GRAPHIC ORGANIZER

2. Using a
bubble
graphic
organizer
, write
down
what
have you
rememb
er from
previous
lesson.
WEATHERIN
G

3. Tray with sand
■think of as many ways as you
can to move the sand from one
end of the tray to the other
blowing, tilting the tray, running water, pushing,

4. EROSION AND
DEPOSITION
Prepared by:
Diane Guilaran
Special Science teacher I

5. WEATHERING VS EROSION
WEATHERING EROSION

6. WEATHERING VS EROSION
WEATHERING
• the
disintegration
and
decomposition
of rock at or
near the Earth
surface
EROSION
• the
incorporation
and
transportation
of material by
a mobile agent
such as water,
wind,or ice

7. TASK:
■ List all the italicized word from the
next succeeding slides
– Identify the meaning of the word
– Search of example pictures

8. Weathering occurs in situ, that is, particles
stay put and no movement is involved.
As soon as the weathering product starts
moving (due to fluid flow) we call the
process erosion.

9. Weathering, erosion/transportation, and
deposition are exogenic processes that act in
concert, but in differing relative degrees, to
bring about changes in the configuration of
the Earth’s surface.

10. EROSION
■ The removal of weathered rock and
soil from its original location
■ remove material through a number of
different agents, including running
water, glaciers, wind, ocean currents,
and waves

11. Deposition
■ These agents of erosion can carry rock
and soil thousands of kilometers away
from their source. After the materials
are transported, they are dropped in
another location

12. AGENTS OF EROSION

13. Running water
■ Moving water is perhaps the most powerful agent of
erosion.
■ Stream erosion can reshape entire landscapes.
■ Water flowing down steep slopes has additional
erosive potential resulting from gravity, causing it to
cut downward into the slopes, carving steep valleys
and carrying away rock and soil.
■ encompasses both overland flow and stream flow

14. Task: In your ½ crosswise yellow pad
■ Differentiate overland flow and
streamflow.

15. Factors that affect stream erosion
and deposition
■ Velocity – dictates the ability of stream to
erode and transport; controlled by gradient,
channel size and shape, channel roughness,
and the amount of water flowing in the
channel

16. Factors that affect stream erosion
and deposition
■ Discharge – volume of water passing through
a cross-section of a stream during a given
time; as the discharge increases, the width
of the channel, the depth of flow, or flow
velocity increase individually or
simultaneously

18. Styles of erosion
■ Vertical erosion (down cutting),
■ Lateral erosion
■ head ward erosion

19. Streamflow erosion occurs through:
■ Hydraulic action
■ Abrasion
■ Solution

20. Streams transport their sediment
load in three ways:
■ solution (dissolved load)
■ suspension (suspended load),
■ sliding and rolling along the bottom
(bed load)

21. A stream’s ability to transport solid
particles is described by:
■ competence (size of the largest
particle that can be transported by the
stream)
■ capacity (maximum load a stream can
transport under given conditions)

22. Deposition occurs when a river loses its
capacity to transport sediments. With decrease
in velocity and competence, sediments start to
settle out. River deposits are sorted by particle
size.

23. Ocean or sea waves
wind generated waves, tsunami, tides,
seiches
waves erode and move sediment along the
shore:
■ Shoreline erosion processes
– Hydraulic action, abrasion, corrosion
■ Transport by waves and currents:
– Longshore current, beach drift

24. Glaciers
■ moving body of ice on land that moves
downslope or outward from an area of
accumulation (Monroe et. al., 2007)

25. Types of glaciers:
i. Valley (alpine) glaciers — bounded by
valleys and tend to be long and narrow
ii. Ice sheets (continental glaciers) — cover
large areas of the land surface; unconfined by
topography. Modern ice sheets cover
Antarctica and Greenland
iii. Ice shelves — sheets of ice floating on
water and attached to the land.
They usually occupy coastal embayments

26. ■ Ice cannot erode the bedrock on its
own. Glaciers pick up rock fragments
and use them to abrade the surfaces
over which they pass.
■ Processes responsible for glacial
erosion: Plucking (lifting pieces of
bedrock beneath the glacier) and
abrasion (grinding and scraping by
sediments already in the ice).
■ Abrasion yields glacial polish and
glacial striations

27. Wind
■ i. Wind erodes by: deflation (removal
of loose, fine particles from the
surface), and abrasion (grinding action
and sandblasting)

28. Wind
■ ii. Deflation results in features such as
blowout and desert pavement.
Abrasion yields ventifacts and
yardangs.

29. Wind
■ iii. Wind, just like flowing water, can
carry sediments such as:
– (1) bed load (consists of sand
hopping and bouncing through the
process of saltation), and
– (2) suspended load (clay and silt-
sized particles held aloft).

30. Groundwater
■ The main erosional process associated
with groundwater is solution.
■ Slow-moving groundwater cannot
erode rocks by mechanical processes,
as a stream does, but it can dissolve
rocks and carry these off in solution.

31. Groundwater
■ This process is particularly effective in
areas underlain by soluble rocks, such
as limestone, which readily undergoes
solution in the presence of acidic
water.

32. Karst topography and its associated
landforms
■ distinctive type of landscape which
develops as a consequence of
subsurface solution.
■ It consists of an assemblage of
landforms that is most common in
carbonate rocks, but also associated
with soluble evaporate deposits.

33. Associated land form in Karst
Topography
(1) Cave/Cavern – forms when
circulating groundwater at or below the
water table dissolves carbonate rock
along interconnected fractures and
bedding planes.

34. Associated land form in Karst
Topography
(2) Sinkholes (Dolines) – circular
depressions which form through
dissolution of underlying soluble rocks or
the collapse of a cave’s roof

35. Associated land form in Karst
Topography
(3) Tower karst – tall, steep-sided hills
created in highly eroded karst regions.

36. Gravity
Mass wasting — the downslope movement of
soil, rock, and regolith under the direct
influence of gravity
i. As the slope angle increases, the
tendency to slide down the slope becomes
greater.
ii. Role of water: adds weight to the slope,
has the ability to change angle of repose,

37. Activity: Annotated sketch of areas
of erosion and deposition
■ Using google map locate a river or coastline
nearest their community.
■ Identify locations of erosion and deposition by
making an annotated sketch of the river or
coast.
■ Explain how the different erosional and
depositional features may have formed. Predict
how the river/coast may change shape in the

38. Rubrics
5 4 3 2

39. FORMULATE THREE
REVIEW QUESTIONS THAT
COVER THE CONTENT OF
THE LESSON.
½ crosswise yellow pad