A late Holocene lake sediment sequence from Livingstone Island, South Shetland Islands, with paleo-climatic implications

• Main Authors: Svante Bjorck, Hannelore Hskansson, Rolf Zale, Wibjorn Karlen
• Other Authors: The Pennsylvania State University CiteSeerX Archives
• Format: Text
• Language: English
• Published: 1991
• Subjects: Key words; Antarctica; I4C chronology; lake sediments; microfossil stratigraphy; palaeoclimatology; South Shetland Islands; Livingstone; Livingstone Island; Midge Lake; Antarc*
• Online Access: http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.468.2241; http://www.geol.lu.se/personal/seb/Publ 1991-95/SB et al 1991.pdf

Island, shows that the lake and its catchment have undergone significant changes during the last 4000 years. Radiocarbon dating (AMS), sediment lithology, and microfossil analyses indicate that the lake was deglaciated over 4000 14C years ago. Distinct peaks in accumulation rates of sediment, Pediustrum algae, pollen and spores, as well as changes in the diatom assemblage, suggest significant environmental changes between ca 3200 and 2700 y BP. These changes are interpreted as reflecting a milder and more humid, maritime climate. The increased humidity can explain independent observations of glacier growth during this period. The combined data also indicate that between ca 1500 and 500 y BP the area might have experienced morecontinental conditions with slightly colder and drier climate than today. Since the 14C dates from the Midge Lake sediments are regarded as reliable and the sediment sequence is rich in tephra layers this sediment sequence will be critical for a forthcoming tephra chronology of the region.