Suchergebnisse

Barton Peninsula is an ice-free area located in the southwest corner of King George Island (South Shetland Islands, Antarctica). Following the Last Glacial Maximum, several geomorphological features developed in newly exposed ice-free terrain and their distribution provide insights about past environmental evolution of the area. Three moraine systems are indicative of three main glacial phases within the long-term glacial retreat, which also favoured the development of numerous lakes. Five of these lakes were cored to understand in greater detail the pattern of deglaciation through the study of lacustrine records. Radiocarbon dates from basal lacustrine sediments enabled the reconstruction of the chronology of Holocene glacial retreat. Tephra layers present in lake sediments provided additional independent age constraints on environmental changes based on geochemical and geochronological correlation with Deception Island-derived tephra. Shrinking of the Collins Glacier exposed the southern coastal fringe of Barton Peninsula at 8 cal ky BP. After a period of relative stability during the mid-Holocene, the ice cap started retreating northwards after 3.7 cal ky BP, confining some glaciers within valleys as shown by moraine systems. Lake sediments confirm a period of relative glacial stability during the last 2.4 cal ky BP. © Cambridge University Press 2019. ; The authors are grateful to the Portuguese Polar Program (PROPOLAR), the Korea Polar Research Institute (KOPRI) and the Chilean Antarctic Institute (INACH) for providing logistic support for the fieldwork. Marc Oliva is supported by the Ramón y Cajal Program (RYC-2015-17597) and the Research Group ANTALP (Antarctic, Arctic, Alpine Environments; 2017-SGR-1102) funded by the Government of Catalonia through the AGAUR agency. The work complements the research topics examined in the PALEOGREEN (CTM2017-87976-P) and CRONOANTAR (CTM2016-77878-P) projects of the Ministry of Economy, Industry and Competitiveness, Spain, and the projects Analysis of nunataks of the Antarctic Peninsula as multiproxy data sources on environmental change and climate dynamics – NUNANTAR (02/SAICT/2017 – 32002) and Holocene environments in Barton Peninsula (South Shetland Islands, Antarctica) funded by the Fundação para a Ciência e a Tecnologia, Portugal. ; Peer reviewed