This report covers the area of the Irish Sea between the North Channel and St George's Channel. A wide range of geological features are studied. For example, the channel is thought to contain rocks from the geological systems, ranging from the Precambrian schists and gneisses to Cretaceous chalk and Paleogene basalts. Offshore, Carboniferous and permo-Triassic strata dominate, and have considerable economic interest. The Carboniferous rocks contain coal and advances in technology may renew commercial interest offshore. The report also provides insights into sedimentary processes at work in the Irish Sea. The adjacent land areas include a number of major conurbations, all of which discharge effluent into the sea.