I noticed in an earlier thread you pointed out that the polygons resemble cracks found in drying mud.

Could we be looking at a dry lakebed or flood plane?

It seems like if sediment is suspended in water during a "cyclic", "annual" or seasonal flooding (melt) it would settle out and be uniformly deposited like the layers in the image.

"When layers of rocks are roughly parallel to the surface, their differential erosion looks like a topo map."

There is also something about the layers that distinctly separates them physically from other layers. They break off in 'shelves'. What If the lake had a chance to dry out between flooding? Could the hardening of the previous deposit account for the slip plane between it and the next deposit?

Or am I all wet?