The recent depositional architecture of the north-western Barents Sea continental margin derives from past climate changes with alternating deposition of highly consolidated glacigenic diamicton (continental shelf) and debris flows (continental slope) associated to shelf-edge glaciations, and low-density, normally consolidated biogenic-rich sediments deposited during interglacial conditions. In addition, sub-bottom records outline the presence of acoustically laminated deposits locally having thickness of more than 10 m, which lithofacies characteristics indicate deposition from turbid meltwaters (plumites) during short-living, phases of glacial retreat (meltwater pulses, MWP). One of the youngest stratigraphic intervals recognized along the NW Barents Sea margin was related to the MWP-1a that was responsible for the deposition of about 1.1 x 1011 tonnes of sediments on the upper slope of the Storfjorden-Kveithola TMFs (south of Svalbard) (Lucchi et al., 2015). New compositional analyses of such plumites revealed a distinct signature that allow us to distinguish deposition from glacial melting form that related to the ice-sheet sub-glacial erosion and transport to the edge of margins. Sediment facies and compositional analyses lead to a new climate-related interpretation of the laminated deposits recognized during Marine Isotopic Stages 3 and 2 on the NW margin of the Barents Sea, including Heinrich Event H2.
The Climatic Significance of Laminated Sediments on the NW Barents Sea (Arctic)
Caterina Morigi;
2018-01-01
Abstract
The recent depositional architecture of the north-western Barents Sea continental margin derives from past climate changes with alternating deposition of highly consolidated glacigenic diamicton (continental shelf) and debris flows (continental slope) associated to shelf-edge glaciations, and low-density, normally consolidated biogenic-rich sediments deposited during interglacial conditions. In addition, sub-bottom records outline the presence of acoustically laminated deposits locally having thickness of more than 10 m, which lithofacies characteristics indicate deposition from turbid meltwaters (plumites) during short-living, phases of glacial retreat (meltwater pulses, MWP). One of the youngest stratigraphic intervals recognized along the NW Barents Sea margin was related to the MWP-1a that was responsible for the deposition of about 1.1 x 1011 tonnes of sediments on the upper slope of the Storfjorden-Kveithola TMFs (south of Svalbard) (Lucchi et al., 2015). New compositional analyses of such plumites revealed a distinct signature that allow us to distinguish deposition from glacial melting form that related to the ice-sheet sub-glacial erosion and transport to the edge of margins. Sediment facies and compositional analyses lead to a new climate-related interpretation of the laminated deposits recognized during Marine Isotopic Stages 3 and 2 on the NW margin of the Barents Sea, including Heinrich Event H2.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
