Time: 5 or 6 days
Discussion and overview of material (use as information resource).There are three major kinds of rocks. Igneous rocks form from molten rock (magma) that has cooled; for example granite, quartz and pumice (lava that has cooled and solidified). Igneous rocks are hard because they mostly consist of interlocking crystals formed as the molten magma slowly cooled. Volcanic lava cools too quickly for the molecules to arrange themselves into crystals. When sediments are compressed by the layers above them, they solidify and harden to form sedimentary rocks like sandstone and limestone. Sedimentary rocks are usually composed of layers that were originally laid down by wind or water. Limestone, which has a high calcium content, is a sedimentary rock that forms from the shell remnants of sea creatures. Sedimentary or igneous rocks that are altered by heat, pressure or chemical action change into metamorphic rocks. For instance, sandstone forms quartzite and limestone will change into marble. Metamorphic rocks are crystalline and often will appear as wavy bands and strips.
Earth's continents are part of large crystal plates that are gradually moving as they drift upon the partially molten rock below. Points of contact along the edges of these plates, where they are grinding together or pulling apart are places where earthquakes and volcanoes are thrust up. The other plate is depressed and those rocks are heated and melted to form magma. In this way a rock cycle occurs over millions of years as rock is heaved up, eroded into sediments, pressed down into the Earth's crust and finally uplifted once again.
Surface rocks experience heat, cold, water, wind, and ice. These forces caused weathering of the rocks, breaking them down into smaller pieces over time which forms the mineral basis for soil. Lichens (plants that are really an association of an algae and a fungus) can grow on bare rock by producing food from sunlight and obtaining minerals from the rock with their strong dissolving acids. Whenever small pockets of soil accumulate in the cracks and crevices of rocks, they afford places for the windblown spores of mosses and plant seeds to germinate. Weathered rocks and dead plant and animal remains, called organic matter, continue to build the soil over time. This is called primary succession. Soil supports the plant growth which makes life on Earth possible.
Grades will be given for illustrations of the story, overlay/diagram, explanation of overlay, and group participation in the rock game.
Introduce the topic to be studied: the rock cycle. Discuss the resource/discussion material and take notes to put in their reference journals. Notes to emphasize will be placed on the overhead. Vocabulary will be placed on the overhead. Students will place these and definitions on index cards and place them in geography vocabulary file boxes. Vocabulary: igneous rocks, magma, sedimentary rocks, metamorphic rocks, limestone, rock cycle, earthquakes, volcanoes.
Read "Rock to Rock: A Fantastic Journey". Lights out- music quietly to set the mood-eyes closed. Emphasize that these events would happen over thousands or millions of years. Some classes may want it read more than once. From memory each student will illustrate with pictures what they imagined during the fantasy journey. At random ask for volunteers to share their experiences at the end of class.
Review vocabulary (10 minutes). Set the scene on the overhead for creating a diagram with overlays depicting the rock cycle. The scene will be explained by use of a diagram with overlays already constructed. Students will then begin to construct their own diagram/overlays of the rock cycle. A legend needs to be used to show stages of the cycle and colors used. After constructing the cycle and reviewing notes students will compose their own paragraphs of explanation of the rock cycle.
Divide into cooperative learning groups (4 or 5 depending on class size). Have a collection of rocks available if your school yard has no rocks of any sort around. Each student will select from the collection or find outside the classroom a small rock of about 1 to 2 inches in diameter. They will get to know the rock very well by the feel of it, especially its shape, weight, and texture. The rock should be marked by each student for identification later. Each group collects the rocks in a bag. Take turns trying to pick their own rock by sense of feel alone. Discourage peeking. When each student has found their rock, they may decorate it and take it home for a keepsake from the rock study.
Write the experiences you felt while attempting to find you own rock. Retrace activities from this project and develop a few paragraphs of what you may have learned. Did you enjoy the activities? What suggestions might you have for future activities related to this subject? Note any concepts you did not fully understand so these can be reviewed in an oral brainstorming session tomorrow.
Imagine that you are a rock as big as a baseball. Your home is on a sunny hillside and you can see down into a deep valley with a river roaming far below. You like your home. Sometimes it is very hot there. Can you feel the sunlight warming you?During the winter you get worried about the ice that freezes in the crack on top of you. This crack grows bigger each year because the ice pushes hard on the sides of the crack.
One spring it is very wet, wetter than you can ever remember. The rain pours in little streams rushing down the hillside. Feel the water flowing over you and into the soft mud below.
Suddenly you feel a rumbling and the Earth begins to shake. You look uphill and a large wall of mud rushes down and sweeps you up. You begin to roll down, down, down into the valley. Ow! You hit another rock and you split along the crack. Now you are two halves rolling down the hill.
Splash! You land in the river. For days and days you are pushed by the swift, strong waters. Rolling and bumping along you are getting all broken up into gravel and sand. Finally the river enter the ocean and your many pieces settle onto a large, flat area along with millions of pieces of sand, gravel and silt.
Some pieces settle on top of you and you are getting squished. You yell out, "Stop pushing!" but more and more weight presses down. Your pieces get pushed and stuck together with other pieces. You are now hardening and becoming a sedimentary rock.
The pressure grows and you begin to get warmer and warmer. You change color and form into many hard crystals. Now you're a metamorphic rock.
You keep getting pushed farther down. It is hot. It is boiling hot! Everything begins to melt and you are part of a hot mass of melted rock called magma deep underground. It seems like forever that you are part of this big melted sea of rock. Will you ever see the sun again? You want to be back on your hillside feeling the hot sun and cool wind and rain.
Wait, you're being pushed up and the Earth is shaking and rumbling again. You can feel yourself rising higher and higher. Fire, ash, dust, and steam surround you and, with a loud explosion, you burst up out of the top of a volcano. Red-hot lava is all around. You are a scalding, steamy piece of lava shooting through the air when, suddenly, you land on a high point of the volcano away from the hot flow of lava below.
Slowly the volcano begins to quiet down and the lava cools and hardens. You are now a cold, grey igneous rock on top of a high volcano looking down at a river flowing far below. When the dark ashes blow away and the sky clears, the sun comes out and warms you high up on the volcano- your new home.
Keepers of the Earth, Caduto and Bruchac