Let's get sedimental: A study of the process of sediment deposition and particle sorting
Summary
In this classroom lab, students will investigate particle sorting and deposition. Students will combine gravel, sand, clay and potting soil in a 2L bottle, add water and shake the contents. The top of the bottle will be cut off and the water allowed to evaporate. Once the sediments have settled and dried, students will cut the bottle in half and observe the cross section. Students will make observations with a small group and record observations in their science journals
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Learning Goals
The goal of this lesson is for students to observe the way particles are sorted during deposition and to form hypotheses as to why sorting occurs in this way.
Context for Use
This activity takes 2 or 3 50-minute periods to complete. The first period will be used filling the bottles and cutting off the top of the bottles. The second class period will only be a partial period, but will be used for siphoning off water on the surface of the sediment in order to speed drying time. The third period may be 1 or 2 weeks later (depending on how quickly the sediment dries) so students can cut and examine the cross section of their sediment. In my opinion, this lesson can be used at almost any grade level where deposition and particle sorting is taught.
Description and Teaching Materials
Materials: 2 liter bottle for each group, sand, gravel, clay-rich soil, potting soil, scoops, newspaper, pipette, scissors, and water.
Procedure: groups add several scoops of gravel, sand, clay-rich soil, and potting soil to their bottle. Once material has been added, students should fill the bottle with water such that the surface of the water is one inch above the surface of the sediment. Replace the cap and shake. Cut off the top of the bottle about one inch above the surface of the water.
Set in the sun to allow to dry. Once all of the water has evaporated, cut the bottle and sediment vertically, creating a cross section. Students then make observations about where each of the different sediments ended up. Students will need to generate hypotheses as why this sorting occurs.
Holt Earth Science. Holt, Reinhart, and Winston. 2006
Procedure: groups add several scoops of gravel, sand, clay-rich soil, and potting soil to their bottle. Once material has been added, students should fill the bottle with water such that the surface of the water is one inch above the surface of the sediment. Replace the cap and shake. Cut off the top of the bottle about one inch above the surface of the water.
Set in the sun to allow to dry. Once all of the water has evaporated, cut the bottle and sediment vertically, creating a cross section. Students then make observations about where each of the different sediments ended up. Students will need to generate hypotheses as why this sorting occurs.
Holt Earth Science. Holt, Reinhart, and Winston. 2006
Teaching Notes and Tips
It is important to note that the teacher must be very organized in order to manage all of the materials involved in this activity.
In terms of instruction, in the past I had merely used this activity to illustrate concepts that I had already taught to my students. Now I use this activity before teaching any concepts because I've found that students more easily understand what is being taught.
In terms of instruction, in the past I had merely used this activity to illustrate concepts that I had already taught to my students. Now I use this activity before teaching any concepts because I've found that students more easily understand what is being taught.
Assessment
I use a formative assessment, called an exit slip, immediately following the first and third periods in order to get an idea of how well my students have learned the intended objectives. This slip is not used for grading purposes, just to inform my instruction. If additional instruction is necessary then I add activities as necessary. I will also collect journals to see what conclusions the students have come to about particle deposition and sorting. Ultimately this will be tested in a quiz and a unit test
Standards
8.III.A.2 Earth's composition, structures and processes
8.III.A.4 Earth's composition, structures and processes
8.III.A.4 Earth's composition, structures and processes