Sediment Jar Assignment
- one glass jar, pickle jar works well, wash the jar and keep the lid!
- variety of dirt, sand, small gravel, clay, whatever you can find in your yard or nearby, enough to fill 1/2 of your jar and no more. Nothing larger than 1/4 inch diameter, so no large rocks. You can use material from different locations like I did, or you can use material from just one location if it has a range of grain sizes. DO NOT use potting soil or organic material like mulch, leaves or grass, these are not sediments.
Mix all of your dirt, sand, clay, and gravel together and put it in the jar, filling it up no more than ½ full. Be sure that you break up any clumps of materials so they will settle correctly. No lumps! Add enough water to almost fill the jar, leave about an inch of air at the top. Put the lid on and shake the jar very thoroughly. Sit the jar in a spot that you can leave the jar undisturbed for a few days. Students have had spouses, children and pets move or break their jar so put it in a protected spot. Take photos of the jar at the following intervals.
- Right after you shake it up
- 15 minutes later
- 1 hour later
- 3 hours later
- 24 hours later
- 3 days later
Use the same organization as my example below. Post at least 5 pictures of your jar. The first photo should be of your dirt before you put it in the jar. I’d like to see one of the early shots, 5 or 15 minutes, an intermediate shot (either 3 or 24 hours) and the last photo after 3 days. Be sure that the photos are clear and show the materials in the jar in detail and in focus with good lighting. Label the photos with the time or describe them so I know which photo was taken at what time.
Describe what kinds of materials you put in the jar, color, size ranges… and where you collected them. Include a detailed description of each photo and what you see, any layers developing? Again, colors you see, layers you can describe, how clear is the water…. Describe how long it took the water to become clear and for all of the sediment to settle to the bottom of the jar. What settled to the bottom first, what size particles are these relative to the rest of the material? What stayed suspended in the water the longest, what size particles are these, relative to the rest of the material.
This simple jar is an example of how sediments in nature settle out from water and get deposited.
Be sure to answer the following question as a conclusion to your work. Given what you observed in the jar, what would you expect to see in a stream bed if you were able to dig several feet into the sediments in terms of grain size. Discuss based on what happened in your jar.
Post your photos and your answers to the questions above on the Discussion Board. Respond to two of your classmates as usual.
You can watch the following video where a similar experiment is described. Vertical Sorting Demonstration (https://youtu.be/k65hPHfiK1w)
Follow this outline with 3 sections to your lab report.
Sediment Jar Lab