The outcrop is a well-sortedgravelconglomerate, containing well-rounded, smooth, abraded pebbles. Occasional pebbles up to a few centimeters across are embedded in amongst a matrix of finer rounded particles, up to a centimeter across. It has been interpreted as a fluvialsediment, deposited by a vigorously flowing stream, probably between ankle and waist deep. This stream is part of an ancient alluvial fan, which descends from the steep terrain at the rim of Gale crater across its floor.
Remnant of ancient streambed on Mars (white-balanced) (September 14, 2012). (close-up) (3-D version).