Estratigrafía molecular aplicada a la reconstrucción de las temperaturas y las salinidades superficiales del Mar de Alborán desde la última glaciación

Abstract

Sea Surface Temperalures (SST) and salinity anomalies (AS) of the Western Alboran Sea have been evaluated since the Last Glacial maximum (18 ky Bp) using the Uk37 index. This molecular index is based on the determination of two thermic biomarkers which are fossilized in deep marine sediments. The results obtained indicate a warming of about 12°C and higher salinities (AS=2,5%) than present during the last déglaciation (15-9 ky Bp). SST and AS records evolution were not unidirectional along the last déglaciation (15-9 ky Bp); both records indicate a stepwise evolution in which the Younger Dryas and the last Heinrich event can be recognized. Early Holocene (9-5 ky Bp) is characterized by a drop in salinity and high temperatures, conditions which are synchronous with the deposition of the last sapropel (St) in the Eastern Mediterranean.