The islands'coastlines possess varied geology, where precambrian sandstone has eroded into sea caves, and the resulting sand has formed sandspits, cuspate forelands, tombolos, barrier spits, and beaches.
12.
In the case of a cuspate foreland, the prevailing wind and a powerful secondary wind in the opposite direction move shingle down the coastline from both directions to a place where the coastline changes, causing a foreland to develop.
13.
The majority of cuspate forelands are formed over a coastline that juts out into the sea at enough of an angle to allow the drifting beach material to'spill over'as a result of long shore drift in both directions.
