Chironomid-based temperature reconstruction from Burgäschisee, Switzerland

The data herein presents a new chironomid record and associated chironomid-based temperature reconstruction covering the time interval 18,000-14,000 cal. BP from the lacustrine sediments of a kettle hole lake Burgäschisee, Switzerland. Chironomid assemblages show ecological turnover beginning 1,300 years before the onset of the Oldest Dryas / Bølling transition at ca. 14,700 cal. BP and associated increases in chironomid-based temperature reconstructions. These data also include non-chironomid invertebrate remains, including Ceratopogonidae, Daphnia and Ephemeroptera as well as Characean oospores.

Methods
Sample processing: Sediment samples were soaked in room temeprature 10% KOH solution for 6 hours before being sieved through 100 and 200 micrometer sieves. Chironomids were picked from those samples using a Bogorov tray under a stereomicroscope (30 – 50 x magnification). Samples were dried and then mounted on microscope slides using Euparal and identified under at 40 – 100 x magnification  with a composund microscope. The full laboratory methods are presented in the associated manuscript.

For post identification data processing and temperature reconstruction analysis please see the associated publication in Quaternary Science Reviews.