Plate Tectonics, Composition of Earth

We made these books to show the composition of earth: core, inner and outer mantle, and crust. We got the idea here (scroll down), and there's another cute option here. The children quite liked sewing the binding down the middle—they were so surprised at the idea of sewing on paper! :)

Somewhere (where??) we got the idea to use graham crackers on top of peanut butter to model the way the tectonic plates move over the mantle. We used these models to demonstrate the types of faults and plate boundaries. Above, a divergent plate boundary (note the magma welling up in the center to form new crust).

If you take an eye-dropper and wet the graham crackers along the edges, and then push together very slowly, you get a very nice convergent plate boundary (and some fold mountains).

Plate subduction. The lower plate slowly melts and returns to the magma from whence it came.

Because we are nothing if not thorough, we also modeled this process with two pieces of Milky Way bar. This worked better in some ways because it showed how widespread the faulting can be at a plate boundary. It's not usually just a simple uplift in one spot, forming one mountain range. There are cracks and faults in other areas throughout the crust as well.

Someone made a very nice mantle plume which then seeped up between plates to make a volcano. :)

And, lastly, our marshmallow earth models: cut a slit in a marshmallow and insert an M&M candy (represents the inner and outer core of the earth). The marshmallow is the squishy mantle. Dip the marshmallow in melted chocolate and let it harden to form a crust. Yum!