The pasty flow is most evident around the holes along the large block in the bottom left. My explanation for the flows leans towards frost (is snow possible??) accumulating in the intervening spaces between blocks. Frost and sulphate/salts in the soil would intermix. When heated by the sun, the salty frost could form a liquid phase which could turn the soil into a muddy paste. If there's a good accumulation of frost, the lower portion would be more insulated which would allow the paste more time to flow around surface spherules, flow around rock margins and drip into small caveties, as show in Horton's photo.
By the way, Horton, your colour photos and mosaics are amazing! Do you have a site up that shows all the photos you've created?
