Background deposition within the lagoon behind the barrier island is generally mud, but with some sand bodies present. These include washover fans and flood-tidal deltas ([[:File:M91FG192.JPG|Figure 7]]). Washover fans form when storms pitch sand over the barrier bar into the lagoonal area. Flood-tidal deltas develop as a result of the tidal movement of sand through an inlet into the lagoon. These lagoonal sand bodies are characterized by a pinch-out geometry into the lagoonal shales. The shales interfinger with the sandstones, commonly enveloping the sandstones and sometimes isolating them as discrete hydraulic units. | Background deposition within the lagoon behind the barrier island is generally mud, but with some sand bodies present. These include washover fans and flood-tidal deltas ([[:File:M91FG192.JPG|Figure 7]]). Washover fans form when storms pitch sand over the barrier bar into the lagoonal area. Flood-tidal deltas develop as a result of the tidal movement of sand through an inlet into the lagoon. These lagoonal sand bodies are characterized by a pinch-out geometry into the lagoonal shales. The shales interfinger with the sandstones, commonly enveloping the sandstones and sometimes isolating them as discrete hydraulic units. |