Climatic history of Ny-Alesund region, Svalbard, over the last 19,000 yr: Insights from quartz grain microtexture and magnetic susceptibility

Abstract

Twenty sediment samples of a 1 m deep trench were analyzed to decipher the past environmental changes in and around Ny-Alesund, Svalbard, Arctic Region. The quartz grain microtexture reveals predominant glacial activities in the top 40 cm of the section, while the middle 40–55 cm part represents some aeolian activities along with glacial signatures. The bottommost part, in addition to glacial markers, exhibits some aqueous evidences as well. The lithology shows medium-grained sand in the upper part and coarse-grained sand with occasional shell pieces in the lower part. Angular gravels (2 mm–12 mm) are present throughout with increasing size from top to bottom. On the basis of above observations and 14C AMS dates, it can be summarized that after the Last Glacial Maximum (LGM), the pre-Holocene period shows rapid glacial retreat, followed by a warmer period during the early Holocene. Mid- and late Holocene is marked by a predominantly glacial environment characterized by melt water streams originating from the glaciers and flowing into the fjord. Magnetic susceptibility studies have also been attempted and four alternate stages of colder and warmer phases have been established. Though some similarities among the different climatic phases are discernible between the quartz grain microtexture and magnetic susceptibility studies, they are not completely compatible, which is probably due to their different responses to the climatic variations.