The texture appeared almost as if a congealing liquid cover flowed of the surface and dripped down the sides, not unlike what you would find when a cake is frosted with a warm liquid substance. The transect up the eastern wall of the lower terrace, starting at about 529 m also appeared to represent similar type of structure as the bedrock found at the lower terrace. The bedrock appeared as a smooth surfaced grainstone or sandstone, well cemented and heavily grooved, fluted, pitted and with occasional N-S oriented joints. Potholes, similar to those found in bedrock of active streams on land, were observed and contained gravel, pebbles and cobbles. Isolated patches of black-coated bedrock were also found on this wall.
Many overhangs occur which offer refugia to some fish.
In many places a rugged, rubbly look is exhibited in the bedrock. Samples were hard to come by, but some were broken from the outcrop. The top of the upper terrace was reached at 437 m where a smooth and highly fractured bedrock surface exists. Fractures crisscross the surface and many pits have formed along the fractures. Dive 314 started at a depth of 570 m where smooth but fractured hard grainstone or sandstone outcrop was found.