The Last Deglaciation of the Baltic Ice Stream within Bornholm Basin, IODP Expedition 347, Site M0065
Abstract
A major goal of the Integrated Oceanic Drilling Program (IODP) Expedition 347 is to assess the last deglaciation of the Scandinavian Ice Sheet within southern Baltic Sea Basin (BSB). Site M0065 was drilled in the Baltic Sea within the Bornholm Basin in a water depth of 84m. This location provided the opportunity to study the development of the Baltic Ice Lake (BIL) that occupied the southern BSB during this time period. Visual inspection on board and particle grain size analysis of samples taken of cores from site M0065B indicates clay size fraction sediment was deposited down to Core 12H, 36 mbsf, where glacial sand/silt and clay varves are introduced. Within the clay sections color variations are observed indicating a compositional or chemical change. Previous onshore studies looking at glacial till, surface exposure dates, and geochemical wetland data in the area have marked the deglaciation of the Scandinavian Ice Sheet (SIS) 20-14ka, leading to the exposure of Bornholm Island and Site M0065 16.9ka (Anjar et al., 2014). Samples taken from core M0065B (3.2 to 49.1 mbsf) were analyzed for inductively coupled plasma mass spectrometry (ICP-MS) and x-ray fluorescence (XRF) scanning was performed on sections of M0065A (35.01 to 38.51 mbsf) to determine the cause of color variations observed within Site M0065. The results indicate Site M0065 was influenced by a combination of proximal seasonal ice sheet melting within the BIL, sediment deposition within a circulating and non-circulating, stagnant, BIL with changing provenance and lake anoxic conditions.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2018
- Bibcode:
- 2018AGUFMPP23E1532S
- Keywords:
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- 3036 Ocean drilling;
- MARINE GEOLOGY AND GEOPHYSICSDE: 4914 Continental climate records;
- PALEOCEANOGRAPHYDE: 4926 Glacial;
- PALEOCEANOGRAPHYDE: 4954 Sea surface temperature;
- PALEOCEANOGRAPHY