thumb|[[Cross-bedding|Cross-bedded upper shoreface sandstones]]
325px|thumb|right|[[Wave base diagram.]]
Upper shoreface refers to the portion of the seafloor that is shallow enough to be agitated by everyday wave action, the wave base.
Process
The continuous agitation of the sea floor in the upper shoreface environment results in sediments that are winnowed of the smallest grains, leaving only those grains heavy enough that the water cannot keep them suspended.