Longshore drift is a major movement that determines the sorting of pebbles on Lulworth Cove. The swash carries material obliquely up the beach, however the backwash carries it back down the beach by the steepest slope.

         Materials slowly moved along the beach in a zigzag course, the effects of longshore drift can best be seen when wooden groynes have been put in place to prevent material from being moved along the beach. Materials such as sand and shingle may be deposited after reaching an area where the water is sheltered and the waves lack energy. This material maybe temporarily deposited to form a beach. Longshore drift at Lulworth Cove will prove my hypothesis; ‘The pebbles are smaller on the windward side than the non-windward side’.  

     Other processes occurring at Lulworth Cove that determine the shape of pebbles are attrition and abrasion. Attrition is where rock fragments themselves rub against each other, reducing their size and making them more rounded. Attrition would cause the pebbles on Lulworth Cove to break up and become rounder, smoother and less angular, hopefully proving my third hypothesis, ‘The pebbles get smoother as you travel nearer the water.’ Abrasion occurs when moving water bombards the cliff with rock fragments and drags others backwards and forwards over rock surfaces, wearing them away. Abrasion would cause blade pebbles on Lulworth Cove, which hopefully will be shown by Zingg’s Classification. Corrosion is when salts and other acids in the seawater slowly dissolve the cliff; this is also a process at Lulworth Cove causing the cliff to retreat, and making the pebbles smaller in size.

        There are two types of wave at Lulworth Cove: constructive and destructive. Destructive waves are high and sharp, and they accumulate power as they go along. This wave picks up and transports material such as pebbles, sand and grit and throws it at the beach and cliffs, and over time this causes a dent in the cliff face. Constructive waves are flat, weak waves that pick up small bits of grit, and transport the material to the beach, where it is then deposited, causing an increase in land. This would determine the sorting of the pebbles as well as longshore drift. It would prove my second hypothesis, ‘The pebbles are larger towards the cliff’.