Ripple Marks

A short walk in Wadi Amdeh will lead you to a place aged nearly 500 million years ago of metamorphic quartzite. These rocks were originally beach sand. Flowing water or wave action from the ebb and flow of the tide created ripple patterns in the sand. You can see the same effect today by visiting your local beach. Normally these ripple marks are blown away by wind or removed by water action. Here however after the patterns formed they were quickly covered by other sediments giving them a protective covering. Later the rocks were ‘cooked’ and the ripples set harder when during movement of the earth’s crust they were placed under huge pressure that transformed the sandstone into quartzite. The ripple marks of this site are small scale ridges of sand produced by flowing water or wave action. Ripple marks formed by wave action tend to be symmetrical in shape, while those produced by tidal current tend to be asymmetrical in shape. Ripple marks can be used to indicate direction of these early water currents which in this case is NW.