DIATOM RECORDS | North Atlantic and Arctic

Abstract

Preservation of diatoms in sediments of the North Atlantic and Arctic Ocean through geologic time has been highly variable. The North Atlantic Ocean and the Nordic Seas were regions of high biosiliceous productivity until the onset of Northern hemisphere glaciations during the late Miocene. Later, fluctuating Pleistocene climatic conditions had a major impact on diatom productivity in the high-latitude North Atlantic. During interglacials high diatom productivity took place in the North Atlantic, whereas glacial stages are often barren of diatoms due to expansion of sea-ice cover. Diatom species show rapid evolution through time and are therefore an excellent biostratigraphic tool in this area. The high diversity of diatoms in polar and arctic environments also make them one of the most important tools available for paleoclimatic studies through reconstructions of sea-ice margins, oceanic fronts, and distribution of water masses. Diatoms have also been used to provide quantitative estimates of past sea-surface temperatures, which have been used to infer Holocene surface ocean conditions in the high-latititude North Atlantic.