Composizione dei sedimenti moderni Kongsfjorden, Isole Svalbard

This thesis was developed to provide a preliminary analysis of the sedimentary sequence (NYA11_09) in order to discriminate the major ecosystem changes that have occurred in Kongsfjorden over the last ca. 250 years. The main objectives of this thesis were: - to assess the elemental composition of a sediment core collected from the inner part of a fjord in the Svalbard Islands; - to identify the main factors that have regulated the input of detrital and biogenic material to the sampling area. In order to achieve these objectives, the analysis of the main components was carried out using an XRF core scanned Avaatech III° generation, to evaluate the compositional variability of the elements along the entire core. The profiles of selected elemental ratios were discussed. The sedimentary sequence was divided into three sectors (R1-2-3); through the Ti/Ca, Fe/Ca and K/Ca ratios, the detrital input trend was determined, and by using the Ba/Al, Ca/Al and Br/Cl ratios, the biogenic input trend was assessed. The results have shown a greater compositional variability in sector R2, presumably associated with a phase characterized by significant hydrological and climatic changes that consequently affected the composition, flows towards the bottom sediment, and debris inputs. This interval corresponds to an age between 1830 and 1940. Sector R1, from ca. 1940 to the most recent era (modern age) has shown less variability and the changes recorded in both marine circulation and erosion, transport and deposition of sediments of both detrital and biogenic origin are mainly due to climate change since 1950. Sector R3, from ca. the late 1700 to the 1840, seems to record the Little Ice Age.