Development and Migration of Barrier Islands, Northern Gulf of Mexico
Historical evidence and drilling results from published sources and U.S. Coast Survey charts 1 indicate that barrier islands form by upward aggradation of submerged shoal areas. Subsequent extensive barrier island migration may completely obscure conditions of formation of the original barrier island. Migration may take place parallel, perpendicular, or at oblique angles to the mainland shoreline and appears to take place much faster when parallel with the shoreline. No evidence indicates barrier island formation from engulfed beach and dune ridges during the early stages of transgression. Many strand plain and chenier ridges form the same wav as barrier ridges.