COMPARISON OF 2 U(37)K-SEA SURFACE-TEMPERATURE RECORDS FOR THE LAST CLIMATIC CYCLE AT ODP SITE-658 FROM THE SUBTROPICAL NORTHEAST ATLANTIC

U37K is a proxy indicator of sea surface temperature of the euphotic zone. Two records of U37K are compared to assess the validity of this indicator as a proxy of paleo-SST. The site studied (ODP Leg 108, Site 658) is located below the upwelling cell off Northwest Africa. The 658A&B record has already been reported and the main finding was the detection of rapid and large SST oscillations in terminations. Magnetic susceptibility data are used to cross-correlate the new Hole 658C record with that of 658A and B. The oxygen isotope stratigraphic record is used to produce a preliminary time scale. The two SST records of the last 120 ka reveal similar long-term changes for the last climatic cycle which are in agreement with other paleoclimatic indicators such as deltaO-18. Both the new 658C U37K record and the magnetic susceptibility data suggest that the missing record of Stage 4 reported for 658A and B has been recovered in Hole 658C. Detailed comparison of the high resolution records of the first 5 m (25 ka) demonstrates that the U37K index is a reproducible measure for SST reconstruction. For this segment of the record, all features of SST changes reported in the 658A and B curve are confirmed in the new 658C curve. Furthermore SST oscillations of roughly the same magnitude and duration as the ones reported to occur during Terminations have been identified in Stages 3 and 4. These new findings indicate that rapid and large SST oscillations can occur not only during the deglaciation transition, but also throughout the interglacial and glacial stages. Other complimentary proxy studies are needed to understand the mechanisms of these SST changes.