Early Weichselian interstadial sediments at Härnösand, Sweden

The till-covered organic sediments at Harnosand have been resampled and reinvestigated with respect to their micro- and macrofossil content. The sediments were deposited in a shallow freshwater basin with a sandy substratum and probably under oligotrophic conditions. The regional vegetation consisted of a shrub or herb tundra, later changing into an open Betula forest with scattered Picea and Larix. In the lake, submerged plants such as Potamogeton filiformis and Isoetes lacustris grew, together with Carex. On the shores the vegetation consisted of Betula nana, occasional Betula trees, Salix and Selaginella selaginoides. The beetle fauna suggests an average July temperature of 10–11°C. The flora indicates limited leaching and, thus, deposition during a relatively long and warm interstadial is suggested. The Harnosand sediments are subsequently correlated with the Brorup Interstadial.