Deglaciation chronology, sea-level changes and environmental changes from Holocene lake sediments of Germania Havn S?, Sabine ?, northeast Greenland

摘要

Germania Havn S? is located at the outermost coast of northeastern Greenland. According to radiocarbon dating, the lake basin was deglaciated in the early Holocene, around 11,000. cal. yr BP. At that time the lake was a marine bay, but the lake was isolated soon after deglaciation at ~. 10,600. cal. yr BP. The marine fauna was species-poor, indicating harsh conditions with a high sedimentation rate and lowered salinity due to glacial meltwater supply. The pioneer vegetation around the lake was dominated by mosses and herbs. Deposition of relatively coarse sediments during the early Holocene indicates erosion of the newly deglaciated terrain. Remains of the first woody plant (. Salix herbacea) appear at 7600. cal. yr BP and remains of other woody plants (. Salix arctica,. Dryas octopetala,. Cassiope tetragona and. Empetrum nigrum) appear around one millennium later. Declining concentrations of. D. octopetala and the caddis fly. Apatania zonella in the late Holocene probably imply falling summer temperatures. Only moderate changes in the granulometric and geochemical record during the Holocene indicate relatively stable environmental settings in the lake, which can probably be explained by its location at the outer coast and the buffering effect of the neighboring ocean.