A continuous tephrostratigraphic record from the Labrador Sea spanning the last 65 ka
|Author(s)||Rutledal Sunniva1, Haflidason Hafkidi1, Berben Sarah Mp1, Griem Lisa1, Jansen Eystein1, 2|
|Affiliation(s)||1 : Department of Earth Science, University of Bergen and Bjerknes Centre for Climate Research, Bergen, Norway
2 : Norwegian Research Centre (NORCE), Bergen and Bjerknes Centre for Climate Research, Bergen, Norway
|Source||Journal Of Quaternary Science (0267-8179) (Wiley / Blackwell), 2020-10 , Vol. 35 , N. 7 , P. 855-868|
|Keyword(s)||marine tephra, North Atlantic, Quaternary, tephra isochrons, tephrochronology|
Volcanic ash preserved in marine sediment sequences is key for independent synchronization of palaeoclimate records within and across different climate archives. Here we present a continuous tephrostratigraphic record from the Labrador Sea, spanning the last 65.5 ka, an area and time period that has not been investigated in detail within the established North Atlantic tephra framework. We investigated marine sediment core GS16]204] 22CC for increased tephra occurrences and geochemically analysed the major element composition of tephra shards to identify their source volcano(es). In total we observed eight tephra zones, of which five concentration peaks show isochronous features that can be used as independent tie]points in future studies. The main transport mechanism of tephra shards to the site was near]instantaneous deposition by drifting of sea ice along the East Greenland Current. Our results show that the Icelandic Veidivotn volcanic system was the dominant source of tephra material, especially between late Marine Isotope Stage (MIS) 4 and early MIS 3. The Veidivotn system generated volcanic eruptions in cycles of ca. 3.5 ka. We speculate that the quantity of tephra delivered to the Labrador Sea was a result of variable Icelandic ice volume and/or changes in the transportation pathway towards the Labrador Sea.