de.pangaea.dataset930758 und de.pangaea.dataset930796 dataset PANGAEA
info@pangaea.de
https://www.pangaea.de/ information pointOfContact 2026-04-30T21:45:10Z https://doi.pangaea.de/10.1594/PANGAEA.930758 <gco:CharacterString>XRF elemental contents of sediment core POS362-2_33</gco:CharacterString> 2021-04-26T06:21:18 publication https://doi.org/10.1594/PANGAEA.930758 Blanchet, C author Tjallingii, Rik
rik.tjallingii@gfz-potsdam.de
https://orcid.org/0000-0002-9723-3622 information author Schleicher, Anja Maria https://orcid.org/0000-0003-4052-8654 information author Schouten, Stefan
Stefan.Schouten@nioz.nl
author Frank, Martin
mfrank@geomar.de
https://orcid.org/0000-0002-8606-4421 information author Brauer, Achim
achim.brauer@gfz-potsdam.de
https://orcid.org/0000-0002-6655-9451 information author PANGAEA
info@pangaea.de
https://www.pangaea.de/ information publisher tableDigital Ocean deoxygenation is a rising threat to marine ecosystems and food resources under present climate warming conditions. Organic-rich sapropel layers deposited in the Mediterranean Sea provide a natural laboratory to study the processes that have controlled the changes in seawater oxygen levels in the recent geological past. Our study is based on three sediment cores spanning the last 10 thousand years (10 kyr BP) and located on a bathymetric transect offshore the western distributaries of the Nile delta. These cores are partly to continuously laminated in the sections recording sapropel S1, which is indicative of bottom-water anoxia above the western Nile deep-sea fan. We used a combination of microfacies analyses and inorganic and organic geochemical measurements to reconstruct changes in oxygenation conditions at seasonal to millennial time-scales. The regular alternations of detrital, biogenic and chemogenic sublayers in the laminated sequences are interpreted in terms of seasonal changes. Our microfacies analyses reveal distinct summer floods and subsequent plankton blooms preceding the deposition of inorganic carbonates formed in the water-column during spring-early summer. The isotopic signature of these carbonates suggests year-round anoxic to euxinic bottom waters resulting in high levels of anaerobic remineralisation of organic matter and highlights their potential to reconstruct seawater chemistry at times when benthic fauna was absent. Synchronous changes in terrigenous input, primary productivity and past oxygenation dynamics on millennial time-scales obtained by our multi-proxy study show that runoff-driven eutrophication played a central role in driving rapid changes in oxygenation state of the entire Levantine Basin. Rapid fluctuations of oxygenation conditions in the upper 700 m water depth occurred above the Nile deep-sea fan between 10 and 6.5 ka BP while deeper cores recorded more stable anoxic conditions. These findings are further supported by other regional records and reveal time-transgressive changes in oxygenation state driven by rapid changes in primary productivity during a period of long-term deep-water stagnation. completed Blanchet, C principalInvestigator Deoxygenation Geochemistry Nile River Sapropel S1 theme <gco:CharacterString>PANGAEA Keyword List</gco:CharacterString> 1995-01-01 creation PANGAEA
info@pangaea.de
https://www.pangaea.de/ information pointOfContact copyright copyright CC-BY-4.0: Creative Commons Attribution 4.0 International textTable und geoscientificInformation 29.75083 29.75083 31.69317 31.69317 2008-02-16T00:00:00 2008-02-16T00:00:00 0.01 5.58 DEPTH, sediment/rock physicalMeasurement m m AGE physicalMeasurement ka BP ka BP Age, error physicalMeasurement 2s ± ± log-ratio thematicClassification Log ratio of sulfur over chlorine log-ratio thematicClassification Log ratio of potassium over titanium log-ratio thematicClassification Log ratio of titanium over calcium Score thematicClassification Z-scored Log ratio of titanium over calcium text/tab-separated-values unknown https://doi.pangaea.de/10.1594/PANGAEA.930758?format=textfile download dataset The data set was checked for completeness, correctness, and consistency of metainformation. Validity of used methods was checked and - if applicable - precision and range of data. EVENT LABEL: POS362-2_33 * LATITUDE: 31.693170 * LONGITUDE: 29.750830 * DATE/TIME: 2008-02-16T00:00:00 * ELEVATION: -738.0 m * LOCATION: Mediterranean Sea * CAMPAIGN: POS362/2 * BASIS: Poseidon * METHOD/DEVICE: Gravity corer 2008-02-16T00:00:00 Supplement to <gco:CharacterString>Deoxygenation dynamics above the western Nile deep-sea fan during sapropel S1 at seasonal to millenial time-scales</gco:CharacterString> https://doi.org/10.5194/cp-2020-114 Blanchet, Cécile L
cblanchet@geomar.de
https://orcid.org/0000-0002-7146-705X information author Tjallingii, Rik
rik.tjallingii@gfz-potsdam.de
https://orcid.org/0000-0002-9723-3622 information author Schleicher, Anja Maria https://orcid.org/0000-0003-4052-8654 information author Schouten, Stefan
Stefan.Schouten@nioz.nl
author Frank, Martin
mfrank@geomar.de
https://orcid.org/0000-0002-8606-4421 information author Brauer, Achim
achim.brauer@gfz-potsdam.de
https://orcid.org/0000-0002-6655-9451 information author documentDigital Climate of the Past