Local clay-varve chronology in the Karlskrona-Hultsfred region, southeast Sweden

Abstract

A local varve chronology from southeast Sweden between the town of Karlskrona in the province of Blekinge and Hultsfred in the province of Småland is presented. The chronology covers approximately 800 varve-years. The glaciolacustrine varves were deposited in the Baltic Ice Lake during the Late Weichselian deglaciation. The study includes 60 connected and 56 unconnected varve series and shows that the ice recession rates vary between 75–125 m/year and 250–340 m/year in the southern and northern parts of the area, respectively. An abrupt change from thin to thick clay varves was found in the northern part of the area. The change has been correlated with a similar change of silty varves in the bottom bed of one of the delta plains close to the highest shoreline. This change in the meltwater deposition has been hypothetically correlated with the transition between the Older Dryas (GI-1d) and Alleröd (GI-1c) chronozones, or around 13,750 GRIP years.

Key Words:

• Southeast Sweden
• Late Weichselian
• glaciolacustrine varves
• varve chronology
• ice recession rates
• varve thickness
• statistical analysis
• Older Dryas (GI-1d)
• Alleröd (GI-1c)