Sea floor deposits in Keibu Bay and Nõva Bay (northwestern Estonia) and the adjacent offshore area

Grain-size distribution of sea floor deposits of Nõva Bay and Keibu Bay, northwestern Estonia, is discussed.Based on grain-size statistics, the lateral and vertical distribution of different types of bottom sediments is shown and compared for the two bays.The bottom deposits consist mostly of sand (80-100%).The proportion of silt and gravel is considerably smaller: up to 3% in Nõva Bay and up to 7% in Keibu Bay.In Nõva Bay medium sand predominates.Grain-size distribution of deposits is rather uniform and an obvious correlation exists between the occurrence of different fractions and the water depth.In Keibu Bay sand of different grain size prevails.Along the boundary between the mouths of the bays and the open sea, a belt of coarse sand runs parallel with the shoreline.Beyond this belt silt and clay are predominant.