Last updated: June 29, 2016
- Grade Level:
- Upper Elementary: Third Grade through Fifth Grade
- Science,Social Studies
- Lesson Duration:
- 60 Minutes
- State Standards:
- Arizona: S04-S1C3-PO1; S04-S1C3-PO2; S04-S1C4-PO1; S04-S1C4-PO2; S04-S1C4-PO3; S04-S6C3-PO6; SS04-S1C1-PO1; SS04-S1-C1-PO4; SS04-S1C2-PO3; SS04-S1C10-PO2; S05-S1C3-PO1; S05-S1C4-PO1; S05-S1C4-PO1; S05-S1C4-PO2; S05-S1C4-PO3; SS05-S1C1-PO1; SS05-S1C1-PO2
At the end of this lesson, students will be able to discuss the difference between humid and arid environments as it relates to the weathering of artifacts left at the monument by the Salado people as opposed to decomposition of modern items. They will explore the concept of preservation by looking at their own possessions and the importance of traveling in groups when going on a long journey.
The Mote Marine Lab of Sarasota, Florida, collected this information on the decomposition times of various marine debris samples.
ITEM/ TIME TO DECOMPOSE
Glass Bottle/ 1 million years
Fishing Line/ 600 years
Plastic Bottles/ 450 years
Disposable Diapers/ 450 years
Aluminum Can/ 80-200 years
Foamed Plastic Buoy/ 80 years
Foamed Plastic Cups/ 50 years
Rubber-Boot Sole/ 50-80 years
Tin Cans/ 50 years
Leather/ 50 years
Nylon Fabric/ 30-40 years
Plastic Film Container/ 20-30 years
Plastic Bag/ 10-20 years
Cigarette Butt/ 1-5 years
Wool Sock/ 1-5 years
Plywood/ 1-3 years
Waxed Milk Carton/ 3 months
Apple Core/ 2 months
Newspaper/ 6 weeks
Orange or Banana Peel/ 2-5 weeks
Paper Towel/ 2-4 weeks
Acquire representations of at least seven items to be sequenced (ie plastic bag, diaper, apple core, milk carton etc. either actual items or pictures of them) as well as enough Timeline, Items to Bring With You (x2), and What Would You Bring, handouts for each student.
Activity Worksheet: Timeline
Activity Worksheet: Items to Bring With You
Activity Worksheet: What Would You Bring?
In small groups or as a class, have students arrange the items from the Marine Lab Study in the order they decompose. After a few minutes, tell students which ones they got right and have them rearrange the rest until they get the correct order or time runs out. Have them add some or all of these items to the “Marine Lab Timeline” on their Timeline worksheet.
Ask students where you would find yucca fibers on this the “Marine Lab Timeline.”
Explain that archaeologists found yucca fiber sandals in the Upper Cliff Dwelling from 700 years ago, much longer than they would have lasted in a marine environment! Discuss what else they found up there using the Artifacts Found at Tonto National Monument PowerPoint (accessible on the park's curriculum materials webpage).
Discuss where the Mote Marine Lab in Sarasota, Florida, is testing their samples (marine setting), and how it differs from the UCD environment (arid southwest). Explain that things last longer when sheltered from the elements and covered with sediment as opposed to exposed to agents of weathering like the wind and the ocean. Arizona’s environment and the shelter provided by the cave are why the dwellings and artifacts are still here.
Estimate how long modern items from the “Marine Lab” timeline would last in the dwellings. Have students place these on their “In the Dwellings” timeline. (Select modern items from the original timeline e.g. orange peel, aluminum can, plastic bottle.)
Explain that the Salado people left a lot of things behind when they left the Tonto Basin because they could only take what they could carry on their back. Have students fill out the What Would You Bring worksheet with items cut out from Items to Bring With You sheet. Sort students into small groups and fill out the other side in the same way. Discuss the benefits in traveling with others.
Environment: sum of all external conditions affecting the life, development, and survival of an organism, including the biotic (living) and abiotic (non-living) elements.
Preservation: to keep in perfect or unaltered condition; maintain unchanged
Weathering: effect of exposure to the action of the elements
Assessment MaterialsConcluding Discussion Question
What is the difference between finding a yucca sandal in the dwellings versus finding a pack of chewing gum? What is the value of each to the archaeologist? To a hiker?
Have you ever found something outside that didn’t look like it belonged there? Maybe aluminum cans or a plastic bottle? Share experiences!