1. Erosion
Erosion
The removal and transport of weathered materials by natural agents such as
Caused by
Glaciers
Running water
Gravity
Wind
Waves

2. Glaciers
Mass of compacted ice and snow that moves under its own weight

3. Glaciers
Friction at the base of the glacier is reduced by a thin film of melt water.
Glaciers account for about 75% of the fresh water on Earth

4. Glaciers can leave behind large boulders that are known as an erratic

5. Glaciers
Glaciers can move lots of sediment that can carve striations (grooves) into rocks
These Striations show how glaciers moved

6. Glacial Deposits
Drift or Till - all sediment that is deposited by glacial activity
Loess: fine powder, pulverized rock, that blankets much of the northern mid-west
Moraine: ridge or pile of boulders, gravel, sand, and silt left at the end of a glacier
Esker: type of outwash that accumulates in the channels and tunnels of a glacier

7. Glacial Landforms
Horne: a pyramid shaped peak where 3 or more cirques meet
Cirque
Steep-walled bowl-shaped depression

8. Glacial Landforms Trough
U-shaped valley, Glaciers carve U shaped valleys

9. Glacial Landforms Arete Hanging valley
Narrow flat-topped ridge that forms between two parallel troughs or cirques
Hanging valley
Straight drop-off at the end of a trough

10. Glacial Landforms
Moraine: Pile of mixed sediments that have been carried and dropped by the glacier

11. Glacial Landforms
Eskers -Mounds of rock from melt tunnels

12. Streams and Rivers Velocity - How fast the water moves
Gradient - The steepness, the slope that a river or stream travels
Discharge - The amount of water that moves past a certain point in a river in a given amount of time
If there is a steep gradient, high velocity, and a large discharge, then Erosion will be severe!
Rivers have energy to move lots of sediment, and even large boulders.

13. River stages affect: Velocity, Gradient, & discharge which cause Erosion

15. Seven Bends of the Shenandoah
River meanders
Bends in the river, shows how mature a river is.
Is the Shenandoah and old river or a young river?

16. Erosion-Mass Movement
The downward transportation of weathered materials by gravity
Massive Landslide

17. Erosion-Mass Movement
Creep
Slump
Mudflow/Earthflow
Landslide/Rockslide

18. Erosion-Mass Movement: A large mass of sediment drops down!

19. Erosion-Mass Movement
Creep
Very slow movement of earth material.
Caused by repeated freezing and thawing.
Sediments are loosened by expanding frost and contracting thaw.
Leaning fence posts and telephone poles are a sign of Creep.

20. Fence posts leaning due to creep

21. Erosion-Mass Movement
Slump
Slow downward movement of a large mass of soil
Occurs when underlying sediments are weakened by heavy rains
Characterized by a curved scar in the land surface.

22. Slump can cause road hazards

23. Erosion-Mass Movement
Mudflow/Earthflow
Thick pastes of sediments that travel downhill at great speeds
Usually occur in dry areas that get a large quantity of rain all at once
Leaves a cone shaped deposit

24. Mudflow in the Blue Ridge Mooreman’s Gap near Charlottesville

25. Erosion-Mass Movement
Landslide/Rockslide
Fast movement of large blocks of rock
Occurs in very steep vertical cliffs
Accelerated by ice wedging

26. At the bottom of an old rock slide in N.C. 2011

27. Wave Erosion
The crashing of waves on a shoreline combined with storms continually shape the beach. This is a shoreline with erosion.

29. Wind and Waves
Wind moves sand dunes at the beach and in the deserts.

30. Wind and Waves
Wind can carve out landscapes as it carries sediment

31. Wind and Waves
Many storms combine water and wind to cause significant erosion on landforms.
Strong winds are capable of moving large amounts of sediment

32. Deposition: The process of dropping or depositing soil and sediments.

33. Soil (dirt)
Soil includes loose weathered rock, and organic material in which plant roots can grow

34. Soil Composition
Use this pie chart to answer the questions in your notes.

35. Soil Composition
What do the arrows mean?

36. Where soil forms Residual soil Transported soil
The parent rock is the bedrock beneath the soil (the soil has not moved)
Transported soil
Soil forms from parent material left by winds, rivers, glaciers, or soil that was moved from its original location. This soil has been transported by erosion and deposition

37. Factors that affect Soil Composition
Parent material: What bedrock is it from?
Time: How long has it had to decompose?
Plants and animals: How have roots and animals helped break up the rocks? Were there acid producing mosses that help break down the rocks (chemical weathering)?
Topography: What is the shape of the landscape?
Climate: Is it warm & wet? Were there glaciers present? Was there acid rain?

38. Soil Profile
Cross section of soil layers revealing all soil horizons

39. Soil Horizon
A soil layer with physical and chemical properties that are different from adjacent layers
O Horizon= organic material (humus)
A Horizon = topsoil
B Horizon = subsoil
C Horizon = partially weathered parent material

40. Idealized Soil Profile
Humus:
Dark organic matter in soil that is rich in nutrients.

41. Leaching: The removal of nutrients or toxins in soil as water passes through the layers.

42. Soil Texture
The size of soil particles

43. Particle size ranges for sand, silt and clay
 Type of Mineral Particle
  Size Range
 Sand
  millimeters
 Silt
  millimeters
 Clay
 less than millimeters
Large/ Coarse
Medium
Small/ Fine

44. erosion
EROSION

45. Weathering

46. Deposition

47. Sedimentation
to “settle”