Synthesis of Arctic and sub-Arctic coccolith biochronology and history of North Atlantic drift water influx during the last 500 000 years

Abstract

Coccoliths in 68 upper Quaternary cores from the Norwegian and Greenland seas, the Fram Strait, and the European Arctic Ocean are studied. By using semi-quantitative methods, a high resolution biostratigraphy is achieved and a chronology is established through correlation to the oxygen isotope stratigraphy. Abundant coccoliths reflect time periods with influx of North Atlantic Drift water. This occurred during oxygen isotope stage 12 and during stage 11. During oxygen isotope stage 9 and the earliest part of stage 8, North Atlantic Drift water penetrated only into the central Norwegian Sea. During stages 8 and 7, the environment was intermediate glacial with occasional ice melting and low production of coccoliths. The area was probably fully ice-covered during stage 6. The warmest sea surface temperatures during the last 500 000 years are recorded from oxygen isotope substage 5e, indicating the presence of a strong Norwegian - West Spitsbergen Current system, but ice-rafting was extensive in the Fram Strait. North Atlantic Drift water did not influence the study area during substages 5d and 5b but reached into the Greenland Sea during substage 5c. -from Authors