(this submission to the Accretionary Wedge #30 Bake Sale is late due to a missing camera. Luckily, someone found my camera and now I can show off my baking “mistake”)
My original goal was to bake a metamorphic rock cake that had a bimodal distribution of porphyroblasts. I was going to use green & blue sprinkles to defining the schistose layering (micas) and two different sizes of chocolate chips (the normal & minis) to represent a bimodal garnet distribution. Instead of going the “easy” route, I decided to crack open my copy of Fannie Farmer and make the cake from scratch. This is what came out of the oven:
Well, that’s not a schist. So what happened?
I had assumed that the viscosity of the cake batter would prevent the chocolate chips & sprinkles from moving very far within their original location in the pan. However, as the cake went into the oven, the viscosity of the batter went down and the “garnets” started to settle at the bottom of the pan. Which, had I had a way to capture the movement, would have been a great example of crystal settling within a magma chamber:
The blue & green sprinkles were not as heavy as the chocolate chips, so they simply homogenized within the “magma chamber” and gave the cake its green look. My oven also has issues, so even though the middle of the cake had originally swelled and was a good bit higher than the edges, during cooling the center “caldera” of the cake subsided. A similar process occurs with volcanoes when you remove the magma from the chamber either quickly (a massive eruption like Pinatubo in 1991) or slowly draining it (Mauna Loa from 1983-2001):
So, ironically enough, I didn’t produce a schist, but I managed to accidentally make a fairly decent mafic volcano similar to what might be found in Iceland 🙂 I’ll have to try again for the schist sometime this spring.