2. Deposition-Sedimentation the processes that release eroded materials causing sediments to settle into a new location. A. Cause of Deposition: 1. A Decrease wind or water current velocity. Mass Movements Sand Dunes Glacier Moraine Lake Bed Beach Flood Plain Delta

3. B.Factors of deposition: Particle Characteristics 1. Density: High density sediments settle at a high rate. 2. Shape: Round particles settle fast before flat sediments. 3. Size: Larger particles settle faster than small particles. Aluminum 2.7 g/ml Lead 6.5 g/ml

4. C. Patterns of deposited sediments 1. Sorted Sediments: Generally have the same size, shape, & consistency.

5. 2. Unsorted Sediments: Mixed sizes of sediments. Glacial Till Poorly Sorted

6. 3. Vertical Sorting: In sediments of mixed size, the largest particles will settle to the bottom first with smaller material on top. 4. Graded Beds: Show alternating layers of vertical sorting caused by cyclic events like seasonal floods.

7. 5. Horizontal Sorting: Particles are sorted by size; as stream velocity decreases, the largest particles are deposited first followed by sands, silts, clay. Sediment burial with compaction & cementation resulting in lithification.

8. 6. Wind Deposits: Sediments which are sorted into tilted layers show cross bedding. The angle indicates the direction of current.

9. Erosion-Depositional System: Kinetic & Potential Energy exists within a stream. When the amount of material lost from erosion is the same gained by deposition a dynamic equilibrium is reached.

10. Erosion-Depositional System A balance between erosion & deposition. (K E vs. P E ) 1. Straight Channel -Velocity Greatest In____________ -Erosion______________________ -Deposition____________________ 2. Curved Channel -Velocity Greatest _______________ -Erosion_______________________ -Deposition_____________________

11. Stream Velocity controls deposition Largest particles drop out first as flow decreases.