At this stage, the coal swamps of the north-western shore of the island had subsided below the sea so that the Kellaways clay was formed in fairly deep water and the Kellaways sand was blown and washed from what had become the hot desert land.
The coastal areas of the north-western shore of the island, where coal swamps once existed, have now been submerged beneath the sea. This has resulted in the formation of Kellaways clay in relatively deep water and the movement of Kellaways sand from what is now a hot desert landscape.