Santorini’s a volcanic island. But the giant volcano built itself up over a nucleus of much older material, subducted sediments (now metasedimentary rock). This rock is typical of the Cyclades, the circular-shaped archipelago north of Santorini. As we flew there from Athens, I looked out the plane window in jet-lagged wonder at the scene of dry islands in a placid sea.
Here’s one that I saw:
I reckon what we see there can count as our Friday fold. Let’s trace out the bedding:
That’s the sort of fold you would not see from the ground – it is so big that it requires either an aerial perspective or a concerted mapping effort to detect it.
I love living in the age of Google Earth. After I got home, I was able to poke around on that fine program and identify the island I had photographed. It’s a peninsula on the southern part of the island of Antiparos. Here’s a Google Earth screenshot for comparison:
This sort of folding is precisely what we would expect in a metamorphic terrane. However, it’s not the sort of thing we would associate with a volcano. So, we’ll have to keep flying south for that…