posted on Dec, 16 2003 @ 06:48 AM
The ground in that area looks to be most likely a clay (probably bentonite). Bentonite will hydrate at a level that you just can't imagine. Takes
on orders of magnitude more volume of water than its original volume.
Once bentonite-type clays have hydrated they become what is best modeled as a Bingham Plastic or a Herschel-Bulkley fluid. This means they have a
yield point before they will flow...like toothpaste or ketchup only very high yield points. You have to exceed this yield point before the clay
starts acting like a fluid...until then, it acts as a solid (supports weight). But once you exceed it, you have a flowable substance.
This is what is behind these peculiar rock movements. Theory holds that when the flash floods that happen at seasons in the area occur, they wash the
rocks down the adjoining hillsides, the clay has been hydrated, is slicker than snot, but has a yield point that allows the rocks to be supported and
"flow" along the clay instead of embedding (like in mud).
If there is accompanying high winds, the rocks can actually be pushed along until the clay starts dehydrating and the rocks once again rest on a dry,
[Edited on 16-12-2003 by Valhall]