1. Erosion at work

2.  Erosion is the process of moving sediment from one location to another.  The most important force of erosion is gravity.  The most important agent of erosion is water.

3. Running Water – sediments that have been transported through running water appear rounded and smooth and are deposited in sorted piles. Boulders Cobbles Gravel Sand Silt Clay Sorting

4.  Suspension - the moving water picks up small, less dense particles and carries them along.  Saltation - particles with medium size and density bounce along the river bottom.  Rolling - the water can help particles with large size and density roll along the bottom of the river.

5. Water erodes sediment on the outside curves and deposits (drops) sediment on the inside curves.

7. Glaciers – sediments that have been transported by glaciers appear scratched and grooved. They are deposited in completely unsorted piles, because they were dropped during melting. Large boulders can only be transported by glaciers.

8.  U-shaped valleys are made by a glacier.  V-shaped valleys are made by running water.

9. Waves - move in the ocean and pick up rocks. The rocks rub together eventually making sand. If the waves hit land, the water can tear away at the land because it is carrying the rock particles.

10. Wind - sediments transported by wind are deposited in sorted piles. Only very small particles can usually be transported by the wind. Wind erosion is dirt and other particles that are blown around eventually reshaping the land.

11. Gravity – sediments that are transported by gravity are found in piles at the bottom of cliffs or steep slopes. They appear angular (jagged) and unsorted.

12. Erosion leads to…

13. ● Keyword = Drop-off or deposit ● The dropping off (depositing) of rock particles and earth materials (also called sedimentation)

14. ● Particle Size ● Particle Density ● Particle Shape ● Settling Rate & Settling Time

15. ● Large particles: settle quickly ● Small particles: settle slowly ● Tiny particles: only settle out when water is saturated (can’t hold any more of it) or evaporates

16. A B C D C DB

17. ● If particles have the same shape and size... …the denser particles will settle more quickly.

18. ● Depends upon friction (interaction) between water and particle surface Flat, irregular particles Small, rounded particles More surface areaLess surface area Settle more slowly Settle more quickly

19. ● When particles are dropped off, they get sorted (arranged) in a certain way. ● There are 2 types of sorting: 1. Horizontal Sorting 2. Vertical Sorting

20.  Rivers, streams, and oceans carry sediments and deposit them on the basis of density and size and shape. Boulders Cobbles Pebbles Sand Silt Clay Gravel Large, round, densest sediments deposit first Small, flat, less dense sediments second With evaporation, suspended sediment falls

21. ● Usually found underwater ● Sorting goes from bottom to top: Largest to Smallest ● Graded layers can be created, indicating distinct depositional events 3 rd layer 2 nd layer 1 st layer

22. ● Streams: Sometimes when a stream enters a lake, deposits are fanned out in a triangular shape (delta) ● Glaciers: large rocks moved without being broken into smaller pieces – rocks are dropped at the edge as a glacier melts

23.  Look at each picture and describe what type of sediments are present and how the sediments settled out. Fill in the chart with your data. #Type of sedimentsHow or why it settled: 1 2 3 4 5 6 7 8 9 10 11 12