Pilgrimstad revisited - a multi-proxy reconstruction of Early/Middle Weichselian climate and environment at a key site in central Sweden

• Published in: Boreas
• Main Authors: Wohlfarth, B., Alexanderson, H., Ampel, L., Bennike, O., Engels, S., Johnsen, T., Lundqvist, J., Martins, M., Reimer, P.
• Format: Article in Journal/Newspaper
• Language: English
• Published: 2011
• Subjects: Arctic
• Online Access: https://dare.uva.nl/personal/pure/en/publications/pilgrimstad-revisited--a-multiproxy-reconstruction-of-earlymiddle-weichselian-climate-and-environment-at-a-key-site-in-central-sweden(24a4b8d7-cd9f-4bf3-ba20-4d516b114da0).html; https://doi.org/10.1111/j.1502-3885.2010.00192.x

The site Pilgrimstad in central Sweden has often been cited as a key locality for discussions of ice-free/ice-covered intervals during the Early and Middle Weichselian. Multi-proxy investigations of a recently excavated section at Pilgrimstad now provide a revised picture of the climatic and environmental development between ∼80 and 36 ka ago. The combination of sedimentology, geochemistry, OSL and 14C dating, and macrofossil, siliceous microfossil and chironomid analyses shows: (i) a lower succession of glaciofluvial/fluvial, lacustrine and glaciolacustrine sediments; (ii) an upper lacustrine sediment sequence; and (iii) Last Glacial Maximum till cover. Microfossils in the upper lacustrine sediments are initially characteristic for oligo- to mesotrophic lakes, and macrofossils indicate arctic/sub-arctic environments and mean July temperatures >8 °C. These conditions were, however, followed by a return to a low-nutrient lake and a cold and dry climate. The sequence contains several hiatuses, as shown by the often sharp contacts between individual units, which suggests that ice-free intervals alternated with possible ice advances during certain parts of the Early and Middle Weichselian