ABSTRACT
The Dyfi (or Dovey) estuary in Wales at about 52° 30' N, with its adjacent coastal/deltaic plain, is roughly triangular in shape, open to the west toward Cardigan Bay, but partly closed by a sandy spit. With a length of about 9.5 km it covers an area of about 45 km2 with the estuary covering about 17 km2. Estuarine deposition in the Dyfi estuary and the estuarine plain started at about 10,000 BP with relatively deep water subtidal deposition under low-energy conditions of rapidly accumulating sediments in a progressively shallower environment. Along the White Sea, tidal flats and salt marshes occur along the Kandalakhskaya Guba, where the tidal range is between 2 and 4 m, along the deltas of the Onegin and Northern Dvina rivers, and in the Gulf of Mezen where the coast is macrotidal with a tidal range up to above 6 m and a spring tidal range up to 10 m.
