Sedimentation Lab Activity
Adam Fox
A. Standards Addressed:
Standard ES-6: Students will demonstrate an understanding of the dynamic relationship between Earth’s conditions
over geologic time and the diversity of its organisms.
B. Performance Objectives:
 Students will demonstrate a basic understanding of the processes of sedimentation and sediment
transport
 Students will formulate and test hypotheses about how sediments settle out of the water column.
C. Lesson Plan:
The purpose of this activity is to allow students to explore how different types of sediments settle
out of the water column. This activity should be accompanied by a more in-depth discussion of
sedimentation.
Materials:
 Sedimentator tubes. These may be purchased from a number of science supply
companies, or manufactured at home with relatively minimal effort.
 Textbook with sediment classification table.
1. Concept Exploration:
Sedimentator activity on worksheet below.
2. Concept Introduction:
Heavier sediment types require more energy to keep them in the water column. They are the first
to settle out as water movement slows. It does not require very much energy or water movement
to keep fine particles like clays and silts suspended in the water.
Large particles, like boulders, tend to roll along the bottom. Smaller particles like gravel or
larger sand will bounce along the bottom as they move (this is called saltation). Particles that
roll or bounce are part of the bed load. Fine particles are suspended in the water column (the
suspended load), and very small particles (at the molecule-level) are actually dissolved in the
water.
Sediment transport video: http://www.youtube.com/watch?v=B_pTXHFBbas
Video of bed load: http://www.youtube.com/watch?v=OAt-G5mIEZc
Video of suspended load: http://www.youtube.com/watch?v=LWlzHFns06M
In an estuary, a river meets the ocean. The river is flowing relatively swiftly, but as it meets the
ocean, flow rate slows. This means that large particles settle out on the up-river end of the
estuary, while very fine particles remain suspended as the flow pushes them farther out to sea.
Question 18 addresses this point – if you walked along the bottom straight down a river, through
the estuary and out to sea, you would walk across gravel, then sand, and eventually a large
deposited plume of silt, extending seaward.
Leave one of the sedimentator tubes standing, untouched for several days. Have the students
examine it to see how the fine particles very slowly settle out, and the water gets clearer as less
silt is suspended.
Adapted from Ward’s Natural Science Sedimentator Teacher’s Guide.
Additional Resources:
The Basics of Grain Size in a lake system
http://faculty.gvsu.edu/videticp/grainsize.htm
Name__________________________________________________ Date____________________
Sedimentation Lab
Purpose: To make predictions, formulate hypotheses, observe and classify sediments.
1. Look at this list of sediments:
 Clay and Silt
 Animal and Plant Remains
 Ocean Salts
 Boulders
 Gravel
 Sand
PREDICT the order in which the sediments may settle out from a river from FIRST (1) to LAST (6).
1.________________________ 2. ________________________ 3. ________________________
4.________________________ 5. ________________________ 6. ________________________
2. Hypothesis: Why do you think this will happen in the way you predicted?
3. Obtain a sedimentator tube. Examine your sedimentator. What are the four types of sediments you
observe in your sedimentator?
_______________________
_______________________
_______________________
_______________________
4. Gently shake the sedimentator to loosen the sediments. Stand the sedimentator upright on one end,
then gently flip it over so that it stands on the other end.
5. Observe the water and sediments for a few minutes. Repeat step 4.
6. In pencil, draw what you see. Label the sediments. Remember that your sedimentator is a scale
model for what happens in real life.
RESULTS: Sediment Tube
7. Look back at your predictions- Do your predictions match your results?______________________
Why or why not?
8. Use Table 5.1 on page 118 of your book (and the rest of the chapter) to fill out the chart below.
Start with the largest sediment size!
Source of Particle:
Type of Particle
Size of Particle
Terrigenous or Biogenous
Boulder
>256mm (>10 inches)
Terrigenous
9. Conclusion: How do sediments settle out from a river? (Hint: look at your chart!)
10. Gently shake the sedimentator to loosen the sediments. Lay it on its side.
11. Observe the water and the sediments close up at eye level for a few minutes. Repeat 10 and 11.
12. Carefully draw (in pencil) what you see on the diagram below.
River Mouth (Estuary)----------------------------------------------------------------------------------------- Sea
13. Label the sediments in your diagram
(Gravel, Sand, Plant Remains, Clay & Silt)
14. NUMBER each sediment in your diagram according to the order in which it was deposited
(1st, 2nd, 3rd and so on).
15. Slowly tilt one end of your sedimentator up and down. Continue this motion as you observe the
action of the water moving on the sediments.
16. Which sediments float in the moving water?
17. Which sediments move along the bottom?
18. Which sediments remain stationary?
19. Where would you expect to find the finest particles? Towards the mouth of the river or out to sea?
Why would you expect them to be there?