3.  The water has been moved aside for the ease of visualization.  Water has moved landward and deposited a layer of sand over the basement and a layer of mud over the sand.   Then, as the sea retreated, it deposited sand over the mud.  Notice how the layers continue to build upward.  If the water continues to retreat, it will continue to deposit sand over the mud.

On your worksheet, explain why another layer of sand was deposited over the mud layer.

part 3, pg 14