Lacustrine evidence of early-Holocene environmental change in northern Iceland: a multiproxy palaeoecology and stable isotope study

Abstract

Early-Holocene warming in Iceland caused rapid glacial ice melt which led to exposed landscapes on which soils developed and floras quickly established. Our chironomid-based records from northern Iceland suggest temperatures were up to 2—2.5°C warmer than present throughout the first two millennia post deglaciation (~10 500 to 8500 cal. BP) while sedimentary and isotopic data indicate the development of soils within the local environment throughout this period before catchment conditions started to stabilise around 8400 cal. BP. The warming trend over this period was not uniform however, but punctuated by a series of relatively short-lived climatic events. Specifically inwash events are suggested by the δ¹³C_organic, %TOC and C/N data around 9600 cal. BP and 8250 cal. BP and are seen at two independent sites. There is also evidence from the δ¹⁸O_carbonate and δ¹³C_carbonate records which suggests that progressive evaporation of the study lakes occurred from ~8200 cal. BP, the timing of which accords well with other isotopic records of drier conditions from around the North Atlantic.