Deglaciation and Holocene climate change in the Tore Seamount

• Main Authors: Antón López, Laura Ángela, Martín Lebreiro, Susana, Nave, Sílvia, Bellido Martín, Eva, Mata Campo, Maria Pilar
• Format: Conference Object
• Language: unknown
• Published: 2017
• Subjects: cambio climático; Holoceno; desglaciación; Océano Atlántico Norte; congreso; ice core; North Atlantic
• Online Access: http://hdl.handle.net/10261/273735

Past Global Changes. Open Science Meeting (5º. 2017. Zaragoza) The Tore Seamount has a 5500 m water depth deep basin in the middle - isolated from the open ocean, and providing a singular palaeoclimatic record in the North Atlantic Ocean. It is located about 300 km west off the Iberian margin, and we predict acts as a giant sediment trap of subtropical gyre productivity. Core MD13-3473 was recovered using a Calypso giant piston corer during cruise Gateways Tore Eurofleets [MD194], in 2013, onboard the R/V Marion Dufresne. Although the 24 m long sediment record covers the last 430 thousand years (from Marine Isotopic Stage 11 (MIS 11) to the Holocene), this study focus on the last deglaciation period. To establish the best chronostratigraphy for this time interval (6 ky–21 ky BP.) and assess temperature and productivity changes in the Tore Seamount record, different analyses have been carried out at high-resolution: color intensities, physical properties, geochemical composition, organic carbon, microscopical and compositional analysis of lithic particles (ice-rafted debris) and planktonic foraminiferal assemblages. By combining these records, we were able to approach glacial to interglacial changes in temperature and productivity, and identify Heinrich event 1 (HE1), which altogether reveals specific lithological, biological, and physical characteristics. An age model has been developed for the deglaciation based on five AMS radiocarbon ages, and correlation with the GISP2 ice core and d18OG.bulloides curves from other nearby marine cores of the North Atlantic Ocean. Two AMS radiocarbon ages gave anomalous data, due to the presence of reworked material in these samples and pointing to a turbidite deposit in the middle of hemipelagic sediment, whose emplacement was just after HE1. A thorough study of all these data is necessary to prove the singularity and exceptional paleoceanographic capacity of the Tore Seamount as a sediment trap in the North Atlantic. Instituto Geológico y Minero de España, España ...