1. Sorting of Sediments & Age of a Stream
Aim: How is the deposition of sediments sorted?

2. Sorting of Sediments

3. Sediment left behind by glaciers and gravity falls are UNSORTED

4. Sediments that are left behind by streams are SORTED by size.
Decreasing size

5. Horizontal Sorting
As a river flows and enter into an ocean, heavier/larger sediments are dropped off first while smaller particles are carried longer.

6. Horizontal Sorting

7. Vertical Sorting
As rivers enter into standing bodies of water (example: Lakes), sediments are deposited according to size.

8. Graded Bedding
This can occur where a stream enters a lake. Each spring the snow melts causing there to be more water allowing it to carry larger particles and therefore depositing larger particles. By the winter the river has slowed down carrying only small particles and depositing small particles. The whole process will repeat again in the spring.

9. Graded Bedding

10. Stages of a Streams Life

11. Stages of a Streams Life
A stream passes through a series of stages in its lifetime each having certain characteristics.
3 Main Life Cycle Stages
Youth
Maturity
Old Age
Oh Man! Look at the curves on that…
STREAM

12. Youth Narrow V-shaped Downcutting Fast velocity Steep gradient
EROSION IS DOMINANT
Example- Colorado River

13. Maturity
Meanders develop
Floodplains develop
Gradient Lowers

14. Old Age Wide meanders Wide floodplains Low velocity Low gradient
DYNAMIC EQUILIBRIUM-between erosion and deposition
Example- Mississippi River

16. Watershed
Geographic area drained by a particular river or stream; drainage basin

17. Tributary
A stream that flows into another larger stream.