The middle–late Holocene climatic fluctuations recorded in sedimentary sequence of Lake Geographensee, Fildes Peninsula (King George Island, West Antarctica)

The article focuses on the paleoclimatic reconstruction of Holocene environmental changes. To address this issue, a study of the bottom sediments of Lake Geographensee, located on the Fildes Peninsula, King George Island, West Antarctica, was conducted. The lake, located above the maximum Holocene marine transgression limit, preserves an undisturbed sediment record spanning the last 8500 cal. yr BP. The results of lithological, loss-on-ignition, grain size, diatom, and geochemical analyses, along with statistical data processing and radiocarbon chronology of the bottom sediments, are presented. The study allows to identify significant and minor stages of climate change. A prominent warming occurred between ca. 4800–3400 cal. yr BP. Minor warming intervals were identified at ca. 8500–8000 cal. yr BP, ca. 5600–5300 cal. yr BP, ca. 5130–4800 cal. yr BP, ca. 3400–2400 cal. yr BP, and ca. 1200–800 cal. yr BP. A notable cooling stage transpired at ca. 7500–5600 cal. yr BP, with a peak cold period around 7300–7000 cal. yr BP, and possibly at ca. 1800–1200 cal. yr BP. Minor relative cooling phases took place during next periods: ca. 8000–7500 cal. yr BP, ca. 5300–5130 cal. yr BP, and ca. 2400–1800 cal. yr BP. Additionally, short-term relative cooling and warming are suggested to have occurred during the period ca. 800–600 cal. yr BP. Taking into account the absence of suitable glaciers for obtaining the ice core for paleoclimatic records in the considered maritime Antarctic region, this paleolimnological study provides a foundation for broader understanding of the Holocene climate change in the West Antarctica.