Seventh-graders learn about the Grand Canyon
December 3, 2008
By Laura Geggel
Even though most students in Dave Cruz’s seventh-grade science class have yet to visit the Grand Canyon, they’ve still managed to become experts on the geological wonder.
They recently spent a trimester studying the Colorado River, plateaus, deltas and geology, then presented their final projects at Snoqualmie Middle School in the days before Thanksgiving.
“I knew nothing about the Grand Canyon, other than it was big,” admitted Eli Clure.
Cruz began the unit by splitting the students into groups. He asked each student to write a question about the Grand Canyon.
Students wondered about things ranging from “Why does the Grand Canyon have a flat top?” to “How many people have died in the Grand Canyon?”
(The answers are because the Colorado River runs through the Colorado Plateau and about 50 accidental falls resulting in fatalities between the years of 1925 and 2005).
Cruz put each student in charge of a question. If the class answered the question during one of the lessons, the student had to check it off from the list.
For their final projects, students had to answer another question they had about the Grand Canyon and present it to their classmates.
Many students designed filled jars with different layers of peas and beans to exhibit the different layers of rock in the canyon. Other students made PowerPoint presentations and edited movies about erosion and rock types.
Cruz said class lectures and textbook readings would help students sharpen their note-taking skills for high school. For instance, he told them about Major John Wesley Powell, a one-armed Civil War veteran who explored the Grand Canyon in 1869.
Like Major Powell, Cruz found himself attracted to the Grand Canyon. Cruz, who grew up in Tucson, Ariz., first visited the canyon at age 21. He remembered the “jaw dropping oh-my-gosh,” experience he felt as he gazed at the layers of red rock. He and his wife, a science teacher at Tolt Middle School, have since visited the Grand Canyon many times.
Because many of his students have not stepped foot in Arizona, Cruz did his best to bring the environment to them. Through a series of labs, students observed how water could shape a riverbed — Cruz used a plastic box, sand and water to create a mini-environment — and how to identify metamorphic, sedimentary and igneous rocks.
Students easily identified limestone because its calcium carbonate fizzled when mixed with hydrochloric acid.
Cruz taught the students a heat test he learned from his wife to identify another pair of rocks: slate and shale. The rocks appear similar — in fact, slate used to be shale before elements of heat and pressure transformed it.
If both rocks are held to a person’s cheek, the slate will feel cooler.
Seventh-grader Lilly Saffen said she and her friends did an independent rock test of their own.
“We saw a few rocks at the park and looked at them,” Saffen said.
She even used the amateur heat test when trying to identify slate.
Another student, Boone Hapke, created a Styrofoam representation of an unconformity — an occurrence when erosion takes away rock from a specific time period, making the older rock sit next to newer rock. It would be like making a rock sandwich with a 30 million-year-old crust and a four billion-year-old crust and then taking out the sandwich’s insides.
Two unconformities exist in the Grand Canyon, a detail many students drew on their final-project posters.
Tiana Bursten, who reported on plant life in the canyon, including the poisonous flowering haplopappus, said she couldn’t wait to visit the Grand Canyon.
“I think it’s just a pretty fascinating place,” Bursten said.
Comments
One Response to “Seventh-graders learn about the Grand Canyon”
Got something to say?
Before you comment, please note:
- These comments are moderated.
- Comments should be relevant to the topic at hand and contribute to its discussion.
- Personal attacks and/or excessive profanity will not be tolerated and such comments will not be approved.
- This is not your personal chat room or forum, so please stay on topic.
i think u should do more stuff about kids