A continuous tephrostratigraphic record from the Labrador Sea spanning the last 65 ka

Type Article
Date 2020-10
Language English
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
DOI 10.1002/jqs.3241
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.

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Publisher's official version 14 5 MB Open access
Figure S1. Visual biplot comparison of the rhyolitic tephra shards identified at 130–130.5 cm (150–500 µm) compared to the Vedde Ash geochemical envelope. 479 KB Open access
Figure S2. Tephrostratigraphic record from Labrador Sea core GS16‐204‐22CC, 0–540 cm, versus age (ka b2k). 679 KB Open access
Table S1. Age control points in sediment core GS16‐204‐22CC. 66 KB Open access
Supporting information 20 KB Open access
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