for deltaic barrier development proposed by Penland and Boyd (1981). This 

 model suggests that there is an orderly sequence of events that takes place 

 during the evolution of deltaic barrier islands, and the island's position 

 within this sequence can be used to describe its history (Figure 6). The 

 evolutionary sequence begins with an erosional headland whose sediments are 

 deltaic in nature. Subsequent spit accretion on the flanks of this headland 

 and detachment of the reworked headland from the mainland, due to subsidence, 

 produces the barrier island. 



STAGE 3 

 INNER SHELF SHOAL 



STAGE 2. 

 BARRIER ISLAND ARC 



Figure 6. A three-stage model depicting the evolution of a 

 barrier shoreline along abandoned Mississippi River deltas 

 (after Penland and Boyd 1981) 



15 



