Factores que controlan la relación Sr/Ca en foraminíferos planctónicos y su repercusión en las reconstrucciones de paleotemperaturas basadas en corales

Abstract

Samples from core ODP site 977, retrieved in the Alboran Sea (Western Mediterranean Sea), have been studied in order to better constrain the factors controlling the Sr/Ca ratio in planktonic foraminifers. For this purpose, this ratio has been measured in two different species, Neogloboquadrina pachyderma (right coiling) and Globigerina bulloides, in samples from the marine isotope stage 7 (250-190 kyr). The fast and pronounced fluctuations in shell Sr/Ca observed between substages cannot only respond to water salinity, pH nor temperature changes. However, the results obtained suggest that shell Sr/Ca variations in planktonic foraminifers from the Alboran Sea are also related to Sr/Ca glacial/interglacial changes in the ocean. This would mean that the paleotemperature reconstructions based on corals, might be revised since coral Sr paleothermometry would have underestimated sea surface temperature during glacial episodes