PALEOCLIMATE RECORD FOR NORTHWIND RIDGE, WESTERN ARCTIC-OCEAN

Core NWR 5 from Northwind Ridge in the western Arctic Ocean contains a climatic record that extends back for over 1 million years. Dark brow n beds with abundant planktonic foraminifers represent interglacial co nditions, whereas glacial and transitional conditions are represented by lithologies barren or nearly barren of planktonic foraminifers. We conclude that seven, and possibly all nine, interglacials of the Brunh es magnetic chronozone (the last 780,000 years) are represented in NWR 5. For about the last 800,000 years, the western Arctic Ocean apparen tly had a permanent, thick ice cover and was unable to support signifi cant populations of planktonic foraminifers except during major interg lacials when seasonally open and high-productivity surface waters occu rred at least along the basin margins. Our results support previous in terpretations that climate variations in the Arctic are in phase with glacial/interglacial cycles observed in other proxy records of the Bru nhes.