This image shows a classic example of Martian sedimentary rock in Danielson Crater. The many layers of rock are regularly spaced, forming steps; this implies a series of strong cap layers alternating with weaker layers.
At small scale, much of the rock is heavily fractured. Because the fractured pieces neatly fit together, this occurred after the deposit turned to rock.
It is not known with certainty how these rocks formed, but the regularity of the layers suggests a process that repeated many times, perhaps on annual or longer timescales. This suggests that the layers did not accumulate in a series of random events, as layers of crater ejecta might.
