Download BUGS Rocks Station 1 Plate Tectonics and the Rock Cycle

BUGS
Rocks Station 1
Plate Tectonics and the Rock Cycle
Goal: For the children to understand the importance of rocks as the structure of the earth and
rocks’ relationship to plants, animals and us.
Materials:
In Backpack Kit:
• a copy of these written materials
From the BUGS shelves:
• box of rocks with a green lid labeled station 1 (on the Third Grade Shelf)
• hand lenses
From the BUGS drawer:
• map of the earth’s plate tectonics with puzzle pieces
• big chart of the rock cycle
From home:
• an apple cut in half
Activity and Discussion: After reading the materials about rocks, use the apple (described
on the pg. The Rocky Earth) to explain the earth’s layers-core, mantle and crust. Direct the
students’ attention to the plate tectonic map. Discuss how we have come to understand
that the earth’s crust is broken into giant crustal plates, this theory is called plate tectonics.
The plates are floating on the earth’s mantle. Giving each student a plate puzzle piece, use
the metaphor that the plates fit together like a puzzle. Have the students place their piece
onto the map (putting the puzzle together). Have them tell which continent or ocean rests
on or covers the plate they put down. Be sure to have the students notice where we live
and the fault line that is under us. Have them identify the plates involved. Using the hand
motions (on next page), describe how the pieces are drifting on the thick liquidy mantle, like
a stick would drift on the water currents. They have special words to describe how the
plates bump into each other (subduction, collision, seafloor spreading, and transform fault have the students do the hand motions as you define these terms). Explain how these
plates bump into each other helps the earth to move the rock around. The earth is a great
rock recycler. Using the rock cycle chart explain - rocks from the core come to the surface
and cool and get pushed or spewed out of the mantle - the rocks in and on the surface
(crust) become eroded or changed (via heat/pressure or sediments) into other rocks - and
eventually rocks from the surface get pushed under to be melted down and reformed into
new surface rocks. Of course this process takes millions of years. Discuss that there are
three basic categories that all rocks go into igneous, metamorphic and sedimentary. Using
the samples of rock, show the students the examples of the rocks and what some of them,
if conditions are right, transform into.
Rock Key: There are three main types of rock. Each rock is marked with its type I=igneous,
S=sedimentary and M=metamorphic. The letter appears before the name of the rock.