Late Quaternary Glaciations on the Chukchi Margin, Arctic Ocean: Insights From Echo Sounding and Sediment Records

Journal of Geophysical Research Earth Surface, Journal Year: 2025, Volume and Issue: 130(1)

Published: Jan. 1, 2025

Abstract Glacigenic bedforms such as glacial lineations and moraines on the Chukchi East Siberian margins of Arctic Ocean reveal recurrent waxing waning voluminous ice masses. Despite their paleoclimatic significance, timing, geographic distribution, mechanisms these glaciations remain inadequately understood. To enhance our understanding Quaternary history, we study high‐resolution swath bathymetry subbottom profiler data with lithostratigraphy provenance four sediment cores. These characterize deposits last two at margin adjacent basins. In all cores, multiple peaks plagioclase are prominent in both intervals, probably reflecting predominant glacigenic input from Ice Sheet (ESIS). Peaks dolomite quartz trace Laurentide sources around glacial/deglacial interval preceding older glaciation. By integrating seismostratigraphy constrain formation mid‐slope western side Rise to glaciation (estimated age range MIS 4 or 6). Considering coeval erosion off margin, results confirm that ESIS time extended water depths ∼650/950 m Rise/East margin. comparison, (MIS 2 possibly 4) was smaller, identified seafloor imprint limited ∼450 Borderland, while its extent remains be determined.

Language: Английский

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Revision of the Quaternary calcareous nannofossil biochronology of Arctic Ocean sediments

Quaternary Science Reviews, Journal Year: 2023, Volume and Issue: 321, P. 108382 - 108382

Published: Nov. 9, 2023

Despite extensive chronological studies, the relationship between age and sub-seafloor depth of Arctic Ocean sediments remains ambiguous. This prevents confident identification paleoceanographic changes in during Quaternary. Currently, age-depth models derived from uranium-series decay diverge by hundreds thousands years compared to those built on known evolutionary appearances extinctions calcareous nannoplankton, a group globally valuable age-markers. Here we report high-resolution biostratigraphic analysis late Quaternary six cores central (CAO). We applied paired light microscope (LM) scanning electron (SEM) imaging improve nannofossil diagnosis. argue that low abundances poor preservation have led misidentification true stratigraphic critical Pleistocene bio-events underpinned for many sedimentary records decades. The revised biochronology provides radically different geochronological framework CAO – indicating what had previously been identified as Marine Isotope Stage (MIS) 7 (191–243 ka) is older than MIS 12 (424–478 ka). Furthermore, it suggests inferred sub-stages 5 could represent full interglacial periods rather interstadials. results help reconcile dating approaches provide transformative step towards resolving disparity models, bringing us one closer accurate reconstructions based sediment cores.

Language: Английский

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Late Quaternary Glaciations on the Chukchi Margin, Arctic Ocean: Insights from Echo Sounding and Sediment Records

Authorea (Authorea), Journal Year: 2024, Volume and Issue: unknown

Published: March 5, 2024

Glacigenic bedforms such as multiple glacial lineations and moraines on the Chukchi East Siberian margins reveal recurrent waxing waning by voluminous ice masses. Despite their paleoclimatic significance, timing, geographic distribution, mechanisms of these glaciations remain inadequately understood. To enhance our understanding Quaternary Arctic history, we study high-resolution swath bathymetry subbottom profiling data with lithostratigraphy provenance four sediment cores. These characterize deposits last two at margin adjacent basins. In all cores, peaks plagioclase are prominent in both intervals, probably reflecting predominant glacigenic input from Ice Sheet (ESIS). Peaks dolomite quartz for tracing Laurentide sources occur around glacial/deglacial interval preceding penultimate glaciation. By integrating seismostratigraphy constrain formation mid-slope western side Rise to glaciation (estimated age range MIS 4 6). Considering coeval erosion off margin, results confirm that ESIS time extended water depths ~650/950 m Rise/East margin. comparison, (MIS 2 possibly 4) was smaller, identified seafloor imprint limited ~450 Borderland, while its extent remains be determined.

Language: Английский

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Spatial distribution of n-alkanes and GDGTs in the central Arctic Ocean during Marine Isotope Stages 1, 2 and 3

Organic Geochemistry, Journal Year: 2024, Volume and Issue: unknown, P. 104920 - 104920

Published: Dec. 1, 2024

Language: Английский

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