Downcore rock-magnetic properties of ICDP Core 5045-1, Lake Ohrid

Tipo Dataset Classe Dati di campioni fisici (campioni e parametri fisici di rocce, minerali e materiali vari)

Depth, Sediment/rock Susceptibility, Volume Saturation Isothermal Remanent Magnetisation Saturation Isothermal Remanent Magnetization/kappa Ratio S-Ratio (hematite/magnetite) Arm/irm Δ Grm/δ Nrm Hard Isothermal Remanent Magnetization Deep Lake Drilling System

The bulk magnetic mineral record from Lake Ohrid, spanning the past 637 kyr, reflects large-scale shifts in hydrological conditions, and, superimposed, a strong signal of environmental conditions on glacial–interglacial and millennial timescales. A shift in the formation of early diagenetic ferrimagnetic iron sulfides to siderites is observed around 320 ka. This change is probably associated with variable availability of sulfide in the pore water. We propose that sulfate concentrations were significantly higher before ~320 ka, due to either a higher sulfate flux or lower dilution of lake sulfate due to a smaller water volume. Diagenetic iron minerals appear more abundant during glacials, which are generally characterized by higher Fe/Ca ratios in the sediments.While in the lower part of the core the ferrimagnetic sulfide signal overprints the primary detrital magnetic signal, the upper part of the core is dominated by variable proportions of high- to low-coercivity iron oxides. Glacial sediments are characterized by high concentration of high-coercivity magnetic minerals (hematite, goethite), which relate to enhanced erosion of soils that had formed during preceding interglacials. Superimposed on the glacial–interglacial behavior are millennial-scale oscillations in the magnetic mineral composition that parallel variations in summer insolation. Like the processes on glacial–interglacial timescales, low summer insolation and a retreat in vegetation resulted in enhanced erosion of soil material. Our study highlights that rock-magnetic studies, in concert with geochemical and sedimentological investigations, provide a multi-level contribution to environmental reconstructions, since the magnetic properties can mirror both environmental conditions on land and intra-lake processes.

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Citare come

Just J., Nowaczyk N. R., Sagnotti L., Francke A., Vogel H., Lacey J. H., Wagner B. (2015). Downcore rock-magnetic properties of ICDP Core 5045-1, Lake Ohrid, supplement to: Just, Janna; Nowaczyk, Norbert R; Sagnotti, Leonardo; Francke, Alexander; Vogel, Hendrik; Lacey, Jack H; Wagner, Bernd (2016): Environmental control on the occurrence of high-coercivity magnetic minerals and formation of iron sulfides in a 640 ka sediment sequence from Lake Ohrid (Balkans). Biogeosciences, 13(7), 2093-2109 [Data set]. PANGAEA - Data Publisher for Earth & Environmental Science.

Formati di codifica dei dati disponibili tab

Nome campo Valore
Identificativo del dataset (DOI) 10.1594/pangaea.848639
Altro identificativo Codice: ingv_568
Gestore del codice: INGV
Temi del dataset Scienza e tecnologia
Editore del Dataset PANGAEA - Data Publisher for Earth & Environmental Science
Data di rilascio 01-01-2015
Data di modifica 06-10-2021
Copertura Geografica Area di competenza dell'unità organizzativa preposta
URI di GeoNames Non disponibile
Lingue del dataset italiano
Estensione temporale Non disponibile
Titolari University of Cologne
ROR 00rcxh774
Helmholtz-Zentrum Potsdam - Deutsches GeoForschungsZentrum (GFZ)
ROR 04z8jg394
Istituto Nazionale di Geofisica e Vulcanologia (INGV)
ROR 00qps9a02
IPA ingv
University of Bern
ROR 02k7v4d05
British Geological Survey (BGS)
ROR 04a7gbp98
Frequenza di aggiornamento mai
Versione di Non disponibile
Spatial extent {"type": "MultiPoint","coordinates": [[20.715,41.0492]]}
Autori JUST Janna
University of Cologne, Germany
Helmholtz-Zentrum Potsdam - Deutsches GeoForschungsZentrum (GFZ), Germany
Istituto Nazionale di Geofisica e Vulcanologia (INGV), Italy
FRANCKE Alexander
University of Cologne, Germany
VOGEL Hendrik
University of Bern, Switzerland
British Geological Survey (BGS), United Kingdom
University of Cologne, Germany

Schema dati