Geologic Brownie Sundaes: Review of Rocks and Minerals

On the last day of our Rocks and Minerals Unit, we made these Geologic Brownie Sundaes to demonstrate what we had learned.

You need the following things:
1. Brownies (we used my favorite brownie recipe, here, and did the Peanut Butter Swirl variation) to represent metamorphic rock---the brownie batter metamorphoses into something quite different when heat is added! I liked using the marbled brownies because they looked like metamorphic rock!
2. Hot fudge or hot caramel, to represent magma/lava.
3. Ice cream, to represent igneous rock (because it has been cooled and hardened from a liquid).
4. Chopped nuts and/or sprinkles, to represent fossils and sedimentary rock.

Assembled your sundaes in clear glasses, so you can see the layers in cross section. Each person puts in the ingredients in whatever order and quantity he or she wishes. Now the fun begins---you have to narrate the geologic "story" of your sundae. For example:
"A huge deposit of intrusive igneous rock was exposed through weathering (put a scoop of ice cream on the bottom of your bowl). Then a catastrophic eruption of a new volcano occured, burying the old igneous rock and the covering the area with lava (pour hot fudge on top)! After many millions of years, more igneous rock was pushed down by an earthquake at a fault line and heated by the nearby magma, forming metamorphic rock (put some pieces of brownie on top of the lava). The metamorphic rock was covered by sediments from a huge ocean (sprinkle nuts on top of the brownies) and began to re-melt into magma as it was pressed even further into the mantle."

Junie explains her creation

Ky tells his geologic story

I made each person tell me a story like this before eating their brownie sundaes. Some of the stories became very violent, with volcanic eruptions killing poor unsuspecting animals and earthquakes ripping cities apart! You can also talk about the laws of superposition, cross-cutting, etc. when you observe which layers are laid down first in your creation.

Yum!

And, here are a few other activities we did to learn about weathering, etc. that didn't fit well in another post:

Weathering, erosion and deposition sorting activity

Lego weathering, erosion and deposition relay race

Video about weathering and erosion

Pictures showing erosion and weathering

Online weathering and erosion game