Abstract
Northeast Atlantic climate shifted into the Quaternary Ice Age around 2.6 M yr ago. Until now, however, the detailed changes associated with this inception of an Ice Age have remained obscure. New high-quality three-dimensional seismic data reveal a detailed geological record of buried surfaces, landforms and sedimentary architecture over vast parts of the Norwegian North Sea. Here, we show the sequence of near-coast geological events spanning the Northeast Atlantic inception of an Ice Age. We identify the location of immediate pre-glacial fluvially derived sandy systems where rivers from the Norwegian mainland built marine deltas. The stratigraphic position of a large submarine channel, formed by enhanced meltwater from initial build-up of local glaciers, is also shown. Finally, we document the transition to full ice-sheet growth over Scandinavia from the ice sheet’s earliest position to the later pattern of debris-flow lobes reaching the present-day shelf edge.
Highlights
A dramatic climate shift led the Northeast Atlantic into an Ice Age around 2.6 M yr ago at the beginning of the Quaternary Period
In deep-ocean sediments this transition is recorded as increasing volumes of iceberg-rafted debris (IRD) delivered to the surrounding seas as ice sheets built up over the adjacent mid-latitude land masses[1,2]
The Utsira Formation east is bounded at its base by the MidMiocene Unconformity (MMU), an unconformity on the entire eastern basin margin that dips smoothly westwards showing reflection truncation, onlap and downlap[17,18]
Summary
A dramatic climate shift led the Northeast Atlantic into an Ice Age around 2.6 M yr ago at the beginning of the Quaternary Period. The Norwegian Channel Ice Stream, which drained much of the southern Scandinavian Ice Sheet during successive mid- and late-Quaternary glaciations, eroded parts of both the Utsira and Naust formations and formed an Upper Regional Unconformity (URU) at the base of the Norwegian Channel[13,22,23,24]. We use a large (35,410 km2) 3D seismic survey obtained from the northern North Sea between Norway and the Shetland Islands (60–62 °N; Fig. 1a) to investigate the geological record spanning the change from relatively warm and fluvially dominated sediment delivery from land to sea during the Neogene, to a Quaternary environment influenced largely by erosion, transport and deposition from glaciers and ice sheets.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
