Biomarker distributions in sediment core PS2767-4

• Main Authors: Stein, Ruediger, Fahl, Kirsten
• Format: Dataset
• Language: English
• Published: PANGAEA 2012
• Subjects: 2,10,14-Trimethyl-6-enyl-7-(3-methylpent-1-enyl)pentadecene; per unit mass total organic carbon; 2,6,10,14-Tetramethyl-7-(3-methylpent-4-enyl)pentadecane; 24-ethylcholest-5-en-3beta-ol; 24-Methylcholest-5-en-3beta-ol; 24-Methylcholesta-5,22E-dien-3beta-ol; AGE; Arctic Ocean; ARK-XI/1; AWI_Paleo; C25 highly branched isoprenoid diene/IP25 ratio; Calculated; Carbon; organic; total; DEPTH; sediment/rock; Element analyser CHN; LECO CNS 2000; Gas chromatography - Mass spectrometry (GC-MS); KAL; Kasten corer; Paleoenvironmental Reconstructions from Marine Sediments @ AWI; Phytoplankton biomarker Brassicasterol IP25 index; Polarstern; PS2767-4; PS36; PS36/066; Arctic; Lomonosov Ridge; Phytoplankton; Polarforschung; Sea ice
• Online Access: https://doi.pangaea.de/10.1594/PANGAEA.803235; https://doi.org/10.1594/PANGAEA.803235

Here, we present a first (low-resolution) biomarker sea-ice proxy record from the High Arctic (southern Lomonosov Ridge), going back in time to about 60 ka (MIS 3 to MIS 1). Variable concentrations of the sea-ice diatom specific highly branched isoprenoid (HBI) with 25 carbon atoms ("IP25"), in combination with the phytoplankton biomarker brassicasterol, suggest variable seasonal sea-ice coverage and open-water productivity during MIS 3. During most of MIS 2, the spring to summer sea-ice margin significantly extended towards the south, resulting in a drastic decrease in phytoplankton productivity. During the Early Holocene Climate Optimum, brassicasterol reached its maximum, interpreted as signal for elevated phytoplankton productivity due to a significantly reduced sea-ice cover. During the mid-late Holocene, IP25 increased and brassicasterol decreased, indicating extended sea-ice cover and reduced phytoplankton productivity, respectively. The HBI diene/IP25 ratios probably reached maximum values during the Bølling-Allerød warm period and decreased during the Holocene, suggesting a correlation with sea-surface temperature.