Micropaleontological study of a sediment core collected on the Bellsund Drift (Svalbard): the last 2ka.

Abstract

The last 2000 years BP are important to understand the recent climate change. Moreover, the studies of environmental changes recorded in this period offer the possibility to understand how our climate can change in the near future. With these premises, we present the results of the combined study of diatom and foraminifera assemblages together with the sedimentological characteristics of the long Calypso core GS191-01PC. This core was collected on the Bellsund Drift (south-western margin of Spitzbergen) during the expedition of the RV G.O. Sars (5–15 June 2014), in the framework of the Project Eurofleets-2 PREPARED. The study focuses on the 2000 year BP with the final aim to understand paleoclimatic variations. Diatom assemblage shows that warm periods are characterised by Coscinodiscus group and in same levels there are high percentages of the fresh-water diatom Aulocoseia spp. One the other hand, cold periods are characterised by the presence of the cold species Thalassiosira antarctica and higher percentage of the polar planktonic foraminifera Neogloboquadrina pachyderma. The preliminary results of the micropaleontological and sedimentological analyses allow to recognize an alternation four different climatic periods. On the base of the age model, constructed with 14C AMS and paleomagnetic data, we interpret these periods as the Little Ice Age and the Dark Age Period interbedded with the Roman Warm Period and the Medieval Warm Period