1. Chapter 10: Deposition
Workbook p

2. Deposition Opposite of Erosion
Begins with weathering and erosion of materials
To place sediments in a new place
Released, settled, or dropped
Releasing of solid sediments and the process of PRECIPITATION
Releasing of dissolved minerals or salts from a water solution
Forms sedimentary rocks

3. Depositional Features
Beaches, flood plains, deltas, moraines, marine coastal plains, glacial deposits

4. Factors Causing Deposition
If you remember, erosion occurs when the speed of the water in a stream, wind in a breeze, or other erosional surface speeds up
Deposition occurs when these agents slow down or stop
Think of a feather blowing in the wind
When the wind stops, the feather ?

5. Rate of Deposition Time it takes for sediments to deposit
Faster rate of deposition
Less time it take
Slower rate of deposition
More time it takes
TWO factors that affect rate of deposition
Velocity of the erosional system
Sediments themselves

6. 1- Velocity of an Erosional System
ESRT p. 6
Faster a stream flows, the larger sized sediments it can carry
So, if the stream slows down below a certain velocity, it will deposit the sediments it can no longer carry

7. 2- Characteristics of the Sediments Themselves
The actual sediments will determine how fast they will be deposited in air or water environments:
Size
Larger sediments will settle out first
If all other things are equal, the larger one will be heavier

8. 2- Characteristics of the Sediments Themselves
The actual sediments will determine how fast they will be deposited in air or water environments:
Shape
The more rounded the particle, the faster it will settle
Flattened particles have more resistance pushing up on it, settle slower

9. 2- Characteristics of the Sediments Themselves
The actual sediments will determine how fast they will be deposited in air or water environments:
Density
More dense will settle faster.
If all other factors are equal, the more dense will be heavier

10. 2- Characteristics of the Sediments Themselves
The actual sediments will determine how fast they will be deposited in air or water environments:
Saturation of Dissolved Minerals
More saturated materials are more likely to settle out faster

11. Open your workbook to p. 204 (1-4)3
River slows down. Less kinetic energy 4

12. Sorting of Sediments Sorted Sediments
Deposit or layer of sediments that has particles of the same size (or shape or density) together.
Most common type of sorting performed
Usually found in water and wind deposits
The greater the similarity , the more sorted the sediments are
There is vertical sorting and horizontal sorting

14. Graded Bedding
When sorting occurs again and again

15. Unsorted Sediments Mixture of sediments all together
Most common in glacial deposits and mass movements

16. Dynamic Equilibrium A type of equilibrium that is constantly changing
The rate of erosion is equal to the rate of deposition by the system as a whole
If a stream floods, more erosion will occur. Eventually, those particles will deposit somewhere and a new equilibrium will occur.

17. Open your book to p. 206 (5-14) 3 4
Unsorted 1 2

18. Characteristic Features of the Chief Depositional Agents
Each agent has its own characteristic features
5 Agents of Depositioning:
Streams
Glaciers
Waves and Currents
Wind
Mass Movement

19. 1- Streams
Deposited on the inside of meanders, where the velocity is slower
Flood plain- flat region to the sides of a stream where the stream floods
Oxbow Lake- former meander
Curved Lake
Delta- Where a fast moving stream enters a slower moving body of water (lake or ocean)
Horizontal deposition of sediments
Shape of a TRIANGLE
Horizontal and vertical sorting is commonplace

20. 2- Glaciers Sediments deposited by a glacier is called glacial till
Glacial till is angular, poorly sorted, and unlayered
Moraine- the place where a glacier stops moving forward
Sediments are dropped in completely UNSORTED piles
Ground moraines, Terminal moraines
Central Long Island is a terminal moraine from the last ice age
Drumlins
Shaped like the back of a spoon
Points in the direction of the glacial movement
UNSORTED sediment
Kettles and Kettle Lakes
Blocks of ice that were left behind and melted
If it fills with water, it is a kettle lake
Erratic
Piece of rock moved there by a glacier and dropped
Doesn’t look like it “belongs”
Outwash Plain
Similar to a flood plain, but where a piece of a glacier has flooded an area with melted ice
Forms a delta-like feature

22. 3- Waves and Currents
The bottom of waves slow down as the approach the shore
Moves sediment toward the shore
Also, what causes waves to “break”
Beach- strip of sediment at the coastline
Made up of sediment of broken down rocks, etc found just offshore
Why parts of Hawaii has black sand- cooled lava
Why Bermuda has pink sand- red coral and white sand
Why Staten Island has brown sand- clay based
Peninsula or pier- sand will deposit on the side that the waves are going TOWARD it.
The side opposite the waves will have erosion
Sandbar- created by a longshore current
Current that runs parallel to the beach
Shallow spot offshore
Barrier Island
When a sandbar reaches the surface of the water
Water is still between the barrier island and mainland

23. Wave and Current Features

24. 4- Wind Usually only transports sand and smaller sized particles
Silt and clay is called dust
Sand dunes- “hills” of sand
Sloping, sorted sediment
Gentle slope facing the wind and a steep slope on the leeward side

25. 5- Mass Movement Completely unsorted and unlayered sediments
Sharp, angular sides
Pile of sediments at the bottom of a cliff

26. Open to p. 210 (15-25) 2 3 1 4