54. This photograph is an excellent example of an "incipient craterlet". Note the thin, light-colored, bowl-shaped zone (which contains unweathered sand intruded from depth) that passes by the top of the shovel handle. This zone is interpreted to have formed by hydrofracturing of the brittle, humate-enriched cap, which next was intruded with the fluidized mixture of water and the light-colored sand.