FN Archimer Export Format PT J TI Methane seepage at Vestnesa Ridge (NW Svalbard) since the Last Glacial Maximum BT AF SCHNEIDER, A. PANIERI, G. LEPLAND, A. CONSOLARO, C. CREMIERE, A. FORWICK, M. JOHNSON, J. E. PLAZA-FAVEROLA, A. SAUER, S. KNIES, J. AS 1:1;2:1;3:1,2,8;4:1,3;5:2,4;6:5;7:6;8:1;9:1,2,7;10:1,2; FF 1:;2:;3:;4:;5:;6:;7:;8:;9:;10:; C1 UiT Arctic Univ Norway, Dept Geosci, CAGE Ctr Arctic Gas Hydrate Environm & Climate, N-9037 Tromso, Norway. Geol Survey Norway, N-7491 Trondheim, Norway. Plymouth Univ, Sch Geog Earth & Environm Sci, Plymouth PL4 8AA, Devon, England. CALTECH, Div Geol & Planetary Sci, Pasadena, CA 91125 USA. UiT Arctic Univ Norway, Dept Geosci, N-9037 Tromso, Norway. Univ New Hampshire, Dept Earth Sci, Durham, NH 03824 USA. Inst Francais Rech Exploitat Mer Ifremer, Dept Marine Geosci, Plouzane, France. Tallinn Univ Technol, Dept Geol, Tallinn, Estonia. C2 UNIV TROMSO, NORWAY NGU, NORWAY UNIV PLYMOUTH, UK CALTECH, USA UNIV TROMSO, NORWAY UNIV NEW HAMPSHIRE, USA Inst Francais Rech Exploitat Mer Ifremer, Dept Marine Geosci, Plouzane, France. UNIV TECH TALLIN, ESTONIA IF 4.641 TC 31 UR https://archimer.ifremer.fr/doc/00445/55652/60554.pdf LA English DT Article DE ;Micropaleontology;Foraminifers;Stable isotopes;Methane seepage;Authigenic carbonate;Holocene;Pleistocene;Paleogeography;Deglaciation;Arctic Ocean AB Multiple proxies in the geological record offshore NW Svalbard track shallow subseafloor diagenesis and seafloor methane seepage during the Last Glacial Maximum (LGM) extent and the disintegration of the Svalbard Barents Sea Ice Sheet (SBIS). Vestnesa Ridge, located at 79°N and in 1200 m water depth, is one of the northernmost known active methane seep sites and is characterised by a subseafloor fluid flow system, numerous seafloor pockmarks and gas flares in the water column. In this study, we develop a Late Pleistocene and Holocene stratigraphic framework, use stable oxygen and carbon isotope signatures (δ18O, δ13C) of benthic and planktic foraminifera, the mineralogical and carbon isotope composition of methane-derived authigenic carbonate (MDAC) and sediment geochemical data of ten sediment cores to assess methane seepage variability on Vestnesa Ridge. The studied cores cover the age range between 31.9 and 10 cal ka BP and record 32 negative δ13C excursions in benthic and planktic foraminifera with amplitudes down to −29 ‰ VPDB. These δ13C excursions are often associated with elevated Ca/Ti and Sr/Ti elemental ratios in sediments and MDAC nodules. The precipitation of MDAC overgrowth on foraminiferal tests explains most of the negative δ13C excursions. In this dataset, the oldest recorded methane emission episodes on Vestnesa Ridge occurred between the LGM (24–23.5 cal ka BP) and Heinrich Event 1 (HE 1; 17.7–16.8 cal ka BP). Geological indicators for past subseafloor methane cycling and seafloor methane seepage, such as negative foraminiferal δ13C excursions, MDAC nodules, and elevated Sr/Ti elemental ratios recorded in post-LGM sediments, possibly represent vertical migration of the sulphate-methane transition zone (SMTZ) and post-date sedimentation by up to 13.4 ka. However, it is important to note that indications of post-LGM seafloor methane seepage at Vestnesa Ridge also correspond to the established methane efflux chronology for the adjacent Barents Sea shelf, implying that glacio-isostatic adjustments and associated re-activation of pre-existing deep-seated faults after disintegration of the SBIS are likely important controlling factors on fluid migration towards the seafloor. PY 2018 PD AUG SO Quaternary Science Reviews SN 0277-3791 PU Pergamon-elsevier Science Ltd VL 193 UT 000439674100007 BP 98 EP 117 DI 10.1016/j.quascirev.2018.06.006 ID 55652 ER EF