Marine and terrestrial biomarker records for the last 35,000 years at ODP site 658C off NW Africa

Several high-resolution proxy environmental records have been obtained for the last 35 kyr from ODP Hole 658C, a well-studied site ca. 200 km off Cap Blanc, NW Africa. The collective assessment based on the marine proxies (U- 37(K') SST, contents of TOC and chlorins, Upwelling Radiolarian Index and t he percentage of Florisphaera profunda), surprisingly indicates that the la st glacial maximum (LGM) was characterized by warmer sea surface temperatur e (SST), weaker upwelling, and lower marine productivity, compared with the preceding older glacial and subsequent deglaciation periods. Of the terrig enous proxies, the mean grain size of the non-carbonate fraction and the te rrigenous alkane content indicate that wind strength and aridity were high. The weaker upwelling at the 658 site during the LGM may have resulted from changes in the strength and direction of the wind systems and/or shifts in the position and geometry pf the upwelling cell. (C) 2000 Elsevier Science Ltd. All rights reserved.