Clues in the ripples
Ripple marks provide a clue about the environment in which the rocks formed. Today ripples like these form in shallow water, so it’s reasonable to conclude that this rock was deposited in shallow water too. We also know that it was still or standing water, rather than a flowing current, because the ripples are symmetrical, formed by wavelets moving backwards and forwards. Ripples in a current are asymmetric; that is, they have a steep side and a shallow side caused by the movement of water in one direction only.
Find out more on the rocks and pseudofossils page.