I took a rest between flowers and broken bedrock, which form part of a coastal protection along Øresund.
Just before I took off, I saw a drawing on one of the stones. A pattern I’ve never noticed before, even though I have walked many kilometres on bedrock.
My curiosity made me contact a researcher in geology.
Quickly I got a very nice response.
The drawing on the stone is a Ptygmatic Fold.
Watch this linked send to me over variations of foldings.
Our Earth is amazing and so are the help we can get from nice researchers.