The Alboran Sea is a key location for understanding the influence of the Atlantic-Mediterranean gateways on Mediterranean paleoceanography. During Leg 161 of the Ocean Drilling Program (ODP), the JOIDES Resolution reoccupied the area of the Deep Sea Drilling Project (DSDP) Site 121 (Ryan, Hsü et al., 1973), located in the western Alboran Sea Basin (Fig. 1). As a palynological study was made on the long sequence recovered at DSDP Site 121, ODP Leg 161 Site 976 (36°12N, 4°18W) also allowed a good opportunity to obtain a continuous palynological record of the whole Pleistocene and improve our understanding of Atlantic/Mediterranean exchanges during this period.
The palynological study has been performed to allow direct land/sea correlations and simultaneously to show the modifications of western Mediterranean vegetation and the variations of Alboran Sea surface waters (in relation to entering Atlantic water) throughout the whole Pleistocene. Results are compared with the bulk gradient data of organic matter. The major continental and marine events have been linked to global climate and hydrological changes.