Micropaleontology as a tool to date and identify climate events in marine sedimentary records

• Main Authors: Alonso-Garcia, Montserrat, Perez-Tarruella, Javier, Bejard, Thibauld Maxime, Azibeiro, Lucía Alonso, Sierro, Francisco Javier
• Format: Article in Journal/Newspaper
• Language: Spanish
• Published: Cuaternario y Geomorfología 2022
• Subjects: event-stratigraphy; planktonic foraminifers; ice-core records; temperature; δ18O; eventoestratigrafía; foraminíferos planctónicos; testigos de hielo; temperatura; Alta; Greenland; Hielo; ice core
• Online Access: https://recyt.fecyt.es/index.php/CUGEO/article/view/94120

Microfossils are an outstanding tool for climate and oceanographic reconstructions in marine sediment cores because of their high abundance in the sediments and because their tests allow us to perform geochemical studies, particularly those which are made of calcium carbonate. Given that planktonic foraminifer species’ distribution in the modern ocean is intimately related to climate and oceanographic conditions, planktonic foraminifer assemblages have been widely used to reconstruct paleoclimate and paleoceanographic variability. The rapid response of this group of organisms to climate change brings the possibility of identifying climatic events in a sedimentary record and link them to the equivalent event in a reference record with good chronology. This technique is called event-stratigraphy and allows for precise and high-resolution dating of sedimentary records. This is the case, for instance, of event-stratigraphy using the ice-core records of Greenland as the reference record. Additionally, the geochemical analysis that we can perform in the foraminifer tests, such as the oxygen isotopes (δ18O), can also be used for event-stratigraphy at different time scales. In this article, we show how the chronological framework of marine sedimentary records, located nearby the Iberian Peninsula, can be reconstructed comparing the climatic events recorded by the relative abundance of planktonic foraminifers, paleotemperature or δ18O with a reference record. Los microfósiles son una herramienta excepcional para hacer reconstrucciones climáticas y oceanográficas en sedimentos marinos debido a su alta abundancia, y a que muchos grupos permiten hacer estudios geoquímicos, especialmente los que presentan conchas de carbonato cálcico. En particular, las asociaciones de foraminíferos planctónicos han sido ampliamente utilizadas en ese sentido, ya que en el océano actual la distribución de las diferentes especies está íntimamente ligada a las condiciones climáticas y oceanográficas. La rápida respuesta de este grupo de ...