The structure of Termination II (penultimate deglaciation and Eemian) in the North Atlantic

A study of the 140-100 ka interval in core T90-9P from the North Atlantic ( 45 degrees N, 25 degrees W), based on analysis of oxygen and carbon isotope records from planktonic and benthonic foraminifera, and from the bulk sedi ment fine fraction facilitates a detailed paleoceanographic reconstruction of the penultimate deglaciation (Termination II), and of the Eemian intergl acial (delta(18)O stage 5e). The first step of Termination II was character ised by low productivity and a mixed water column, which was a remnant of g lacial conditions. A 3 ka period of relatively stable conditions, with a st ratified water column ('Termination II pause'), occurred half-way through T ermination II, and preceeded a second and more rapid climatic shift. The en d of the deglaciation (Eemian maximum, i.e. isotopic event 5.53) initiated the establishment of strong, seasonal, water column stratification. North A tlantic Deep Water (NADW) production remained low during the complete glaci al-interglacial transition. After the Eemian maximum, NADW prodution was re stored, and bottom waters remained quite stable during the course of the Ee mian, while surface waters gradually cooled in the second half of the stage . A short surface water cooling event accompanied by a reduced seasonal wat er column stratification and nutrient instability occurred at approximately 117 ka BP. (C) 1999 Elsevier Science Ltd. All rights reserved.