Biogenic Silica Indicator of Paleoproductivity in Lacustrine Sediments of Svalbard, Arctic

Abstract

Lacustrine sediments are a reliable source for paleo archives and are used to infer past environmental conditions. Four sediment cores (LA, L-1, L-2 and L-3) collected from the lakes of the Ny-Alesund region, Arctic, were analysed for biogenic silica (BSi) with other biogeochemical proxies like total organic carbon (TOC), total nitrogen (TN), total phosphorus (TP) and calcium carbonate (CaCO sub(3)) to understand the productivity in Arctic lakes. Diatoms are not well preserved in the Arctic region's freshwater lakes, and the overall biogenic silica content was found below. The relatively high concentration of biogenic silica and organic matter in the upper portion of all the cores indicated high productivity due to the influx of meltwater into the lake. C/N ratio in all the cores collected from the lakes was greater than 15, showing the influence of terrestrial organic matter responsible for diluting biogenic silica.