| Summary: | A sediment transect based on ten corings were performed with a Russian peat corer in the aldercarr at Kalvöviken on the Biskopsmåla Peninsula in central Blekinge. Three parallel sediment cores were collected at the master coring point. These cores were subsampled and studied by means of loss of ignition (LOI), mineral magnetic measurements, macrofossil analysis, pollen analysis and structural analysis. The chronology was obtained by radiocarbon dating of two levels and by adopting dates from earlier studies performed at Kalvöviken in 1997-1999. The purpose of this study was to analyse and interpret the local environmental changes that took place around 8200 cal BP when a sudden change in sea level occurred. The stratigraphic records were compared with other similar studies from nearby sites along the coast of Blekinge but also placed in a more regional context. The transect reveals a 15 meter long drift gyttja layer orientated in SE-NW direction. This layer was found between two layers of brackish gyttja. The study shows that the drift gyttja layer was deposited during a period with low water level between ca 8150-8075 cal. BP. The mineral magnetic analysis confirms the assumption of a sudden transition. The plant macrofossils indicate that Kalvöviken during this period was a shore environment with plants such as Carex, Alisma plantago-aquatica, Equisetum fluviatile, Cyperaceae and Phragmites. Datings together with pollen concentration values indicate a short duration of this period, 75 years or less. The drift gyttja layer in Kalvöviken is synchronous with a short temperature anomaly found in ice cores from Greenland, the so-called “8.2 kyr event”. It might have a meteorological explanation caused by differences in air pressure between the Azores and Island, a phenomenon called the North Atlantic Oscillation (NAO). En sedimenttransekt bestående av tio punkter borrades med hjälp av en ryssborr i alkärret vid Kalvöviken på Biskopsmålahalvön i centrala Blekinge. I huvudpunkten togs tre parallella 1 m långa ...
|
|---|