While excavating in the backyard for a future pond, i discovered that the sand (our soil is pure sand) had these interesting patterns where it had not been disturbed (about two feet down)
http://home.csumb.edu/g/garciabarry/world/miscellaneous/squaresand.jpg
WHat’s strange are the block shaped areas which are a lighter, golden colored sand, contrasted with the siltier darker sand.
Digging in the backyard one often finds layers of alternating dark and golden colored sand (which is often very clean).
To give you an idea of what was there before the neighborhood, the city was built on coastal chapparal areas mixed with clumps of Quercus agrifolia. The “soil” which is sand is all older sand dunes. The golden colored sand is very much like the sand at the beach itself (a mile west).
So any ideas as to what could create areas of sand that are almost perfectly rectangular amid swirly areas?
I can imagine in a few million years that it would make an incredibly patterned sand stone!