DINOFLAGELLATE CYSTS AND HOLOCENE OCEANOGRAPHY OF THE NORTHEASTERN ATLANTIC-OCEAN

Dinoflagellate cyst analysis of two sediment cores, taken on the continental slope off the western coast of Scotland, has revealed new detail and complexity in the oceanography of the Holocene. Changes in the dinoflagellate cyst assemblages suggest at least three fluctuations in the strength or disposition of the North Atlantic Current over the last 10 Ka together with a consequent change in the oceanographic regime of the northeastern Atlantic. These changes, based on comparison to well-constrained data from the Arctic, include the first influx of the North Atlantic Current at about 10 Ka, together with some change in oceanography at between 8 and 6 Ka and between 4 and 2 Ka. These oceanographic changes are based upon fluctuations in the numbers of dinoflagellate cysts per gram of sediment and by their relative proportions. Dinoflagellate cysts have, therefore, a significant role to play in reconstructing the complex history of Holocene environmental change.