22 January 2013
Fold mystery – UPDATED
Posted by Callan
What can you tell me about this new fold sample I recently acquired?
Width of sample is 12.5 cm. The face you’re looking at was cut but not polished. Here’s a close up:
With layering annotated, to highlight the disharmonic nature of these folds:
Anyone have any guesses what’s going on here?
——————– UPDATE ——————
Simon Wellings guessed it – this is a lasagna! I changed the color in Photoshop so you wouldn’t be distracted by its foodness, and would instead focus on its foldness.
Thanks for playing along!
Do you see geologic lessons in your food too?
Callan Bentley is an assistant professor of geology at Northern Virginia Community College in Annandale, Virginia. He is particularly interested in structural geology and the evolution of the Appalachian mountain belt. Callan draws cartoons and writes for EARTH magazine. He lives in the Fort Valley of Virginia.
mtb said on 22 January 2013
Looks a little like malachite-type stuff that got deformed. Maybe I am being misled by the colour though…. https://www.google.com/search?tbm=isch&q=malachite&tbs=imgo:1&biw=1680&bih=955&sei=-Zn-UNv2AsOBhQeF44CgCg has some examples that look very vaguely like it….
Possibly a chemical precipitation of some kind? Pretty cool though.
Alternatively, a partially-baked cake was stirred.
poikiloblastic said on 22 January 2013
Looks like the darker green layers were made of stronger stuff – or were more crystalline during deformation – and thus kept their shape better during compression. The light green deformed massively, but was semi-crystalline and so didn’t expand/settle into void spaces.
BlazV said on 22 January 2013
contraction after dehydration?
pr said on 22 January 2013
I’ll be attempt to say there was a kind of disturbances or something like boiling that stopped rapidly due to a difference between two opposite conditions hot and cold
Simon Wellings said on 22 January 2013
Lasagna? If the folding if caused by changes in volume of particular layers, all sorts of tasty shenanigans are possible.
Callan said on 22 January 2013
Congratulations – Simon wins! It’s a photo of lasagna, and then of course I dipped it in Photoshop to obscure it a bit… Nice work.
mtb said on 22 January 2013
Well played. Evil, but well played.
Peter Selkin said on 23 January 2013
Ha! Very clever. Reminds me a little of George Davis’s structural geology pizza. (Didn’t you post on that, too, once upon a time?)
Callan said on 24 January 2013
Aye, it’s true.