Paleoclimatic reconstruction of the past 30.000 years through analysis on calcareous nannofossil assemblages on the west Spitsbergen margin.

The analysis of calcareous nannofossil (CN) assemblages has been proven to be a reliable approach for reconstructing paleoclimatic conditions along Arctic margins, given the high sensitivity of nannoflora to changes in water column parameters (e.g. temperature, insolation, and nutrient availability). The piston core GS191- 01PC was collected from the Bellsund Drift crest on the west Spitsbergen margin during the PREPARED cruise (Lucchi et al., 2014). It was drilled at a water depth of 1647 meters and it consists of 19.67 meters of sediment characterized by a complex stratigraphy. This included bioturbated and laminated sediments, with sparse to massive Ice Rafted Debris, oxidized layers, and two tephra layers. Caricchi et al. (2019, 2022) have extendedly investigated the GS191-01PC core, establishing a robust age model for the region. The CN assemblages were investigated in a 13.90 m bsf segment of the core, covering the last 30,000 years BP (140 samples at 10 cm intervals). The analysis focused on the distribution of species Emiliania huxleyi and Coccolithus pelagicus, alongside reworked specimens and data on total nannofossil abundance (number of specimens/10 mm2). The E. huxleyi/C. pelagicus ratio (H/P; Carbonara et al., 2016) was calculated to investigate oscillations between the warmer West Spitsbergen (H/P > 1) and the cooler East Spitsbergen (H/P < 1) Currents. During the Late Pleistocene, the distribution of E. huxleyi and reworked specimens evidenced the onset of Heinrich (3, 2, 1) and the Melt Water Pulse-1A abrupt events. Throughout the Younger-Dryas and Holocene epochs, fluctuations in total nannofossil abundance and the overall assemblage composition provided insights into events such as the Holocene Thermal Maximum, and the 8.2, 4.2, and 2.8 cooler episodes.