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Zeitliche und räumliche Dynamik des Kohlenstoffs in intermittierenden Quellen - Umweltrelevante Einflussfaktoren und Konnektivität zu Quellbächen

Quellen stellen den Ausgangspunkt des Flusskontinuums dar und sind wichtige Ökotone zwischen Grund- und Oberflächenwasser. Insbesondere intermittierende Quelltypen, die in oberflächennahen, nicht begrenzten Grundwasserleitern mit einem variierenden, vorübergehend grundwassergetrennten Fließregime, kurzen Verweilzeiten und potenziell höheren Konzentrationen an organischem Kohlenstoff (OC) auftreten, haben das Potenzial, die Kohlenstoffflüsse in den anschließenden Quellbächen erheblich zu beeinflussen. Allerdings gibt es hierzu nur wenige Studien und es ist noch unklar, wie sich das variable Fließregime auf die zeitliche Variabilität des OC in diesen für Mittelgebirge typischen vielfältigen Ökotonen auswirkt. In diesem Projekt werden daher die räumliche und zeitliche Dynamik des OC in intermittierenden Quellen, die umweltrelevanten Einflussfaktoren und ihre Auswirkungen auf die Quellbäche in verschiedenen Mittelgebirgen (Rheinisches Schiefergebirge, Erzgebirge, Schwarzwald) untersucht. Insgesamt werden 44 Quellen hydrologisch und biogeochemisch erfasst und die OC-Dynamik auf verschiedenen zeitlichen und räumlichen Skalen quantifiziert. Neben dem permanenten Monitoring der Quellschüttung, elektrischen Leitfähigkeit und Wassertemperatur werden saisonale und ereignisbasierte Messungen des OC, Nährstoffe und stabilen Isotope durchgeführt. Modernste Labormethoden (C/N- und TOC-Analyzer, Picarro) werden zur Erfassung der zeitlichen und räumlichen Variabilität von DOC, POC, optischen Eigenschaften (Fluoreszenz, Absorption), Nährstoffen (PO4, NO3, NO2, NH4) und stabilen Isotopen (18O, 2H) eingesetzt. Zur Identifizierung räumlicher und zeitlicher Muster, Prozesse, Stoffflüsse und Einflussfaktoren werden verschiedene multivariate statistische Verfahren und Modelle eingesetzt (z.B. PCA, PARAFAC, SIMMR, LOADest, machine learning). Funktionelle Nahrungsgruppen der gegenwärtigen Wirbellosenfauna werden bestimmt, um Artengemeinschaften und -vielfalt zu charakterisieren. Diese skalenübergreifende Untersuchung der hydrologischen und biogeochemischen Eigenschaften intermittierender Quellen und ihrer räumlichen und zeitlichen Dynamik wird die Wissenslücke bezüglich der Rolle intermittierender Quellen innerhalb des Flusskontinuums schließen und zum Verständnis der zukünftigen Dynamik von Quellen aufgrund der durch den Klimawandel verursachten Variationen von Niederschlag und Abfluss und der Auswirkungen ihrer Veränderungen sowohl auf das Quellökosystem als auch auf die damit verbundenen Quellbäche beitragen.

Total organic carbon data of the Devonian Kellwasser Crisis interval (ca. 372 Ma) at Winsenberg, Germany

A total of 34 samples (35 cm average sample spacing) were analysed for organic carbon d13C in order to identify the two characteristic positive excursions associated with the Lower and Upper Kellwasser Events. Measurements were carried out at the Analytical, Environmental and Geo-Chemistry Research Group (AMGC) of the Vrije Universiteit Brussel (Belgium). The samples were decarbonated with 10% HCl in two steps, rinsed with milliQ water, and dried in an oven at 50°C. Total organic carbon (TOC) contents and δ13Corg compositions were determined on a Euro EA 150 Elemental Analyzer (CHNS) - Euro Vector HT-PyrOH combustion system coupled to a Nu-Instruments Horizon 2 isotope ratio mass spectrometer.

pXRF data of the Devonian Kellwasser Crisis interval (ca. 372 Ma) at Winsenberg, Germany

A total of 556 samples (3 cm average sample spacing) were collected from the 12 m long Winsenberg section in order to reconstruct a floating timescale using cyclostratigraphic methods and to investigate paleoclimatic dynamics using selected elemental ratios. Samples were measured as a powder covered with Chemplex film on a Bruker S1 Titan 800 portable XRF at the University of Münster with the following settings: 40 kV, 20 mA, no filters, 75 s. Spectra were deconvoluted in Bruker Artrax software, and linearly calibrated using a set of 10 sedimentary standards of known composition and 11 calcite-quart mixtures. The composition of these standards is also included. Selected elemental ratios were tuned via the methods described in the accompanying manuscript, and are included in this dataset as well.

Stable carbon organic carbon isotope ratios of the Devonian Kellwasser Crisis interval (ca. 372 Ma) at Winsenberg, Germany

A total of 34 samples (35 cm average sample spacing) were analysed for organic carbon d13C in order to identify the two characteristic positive excursions associated with the Lower and Upper Kellwasser Events. Measurements were carried out at the Analytical, Environmental and Geo-Chemistry Research Group (AMGC) of the Vrije Universiteit Brussel (Belgium). The samples were decarbonated with 10% HCl in two steps, rinsed with milliQ water, and dried in an oven at 50°C. Total organic carbon (TOC) contents and δ13Corg compositions were determined on a Euro EA 150 Elemental Analyzer (CHNS) - Euro Vector HT-PyrOH combustion system coupled to a Nu-Instruments Horizon 2 isotope ratio mass spectrometer. The results were calibrated using two international standards, IAEA-C6 (sucrose: δ13C = -10.45‰) and IA-R068 (soy protein: δ13C = -25.22‰), together with reference material IVA33802151, which is calibrated against these international standards (organic-rich sediment: δ13C = -28.85‰). This calibration was verified with a further reference material, IVA33802153 (organic-rich soil: δ13C = -22.88‰).

Calibrated pXRF data of the Devonian Kellwasser Crisis interval (ca. 372 Ma) at Winsenberg, Germany

A total of 556 samples (3 cm average sample spacing) were collected from the 12 m long Winsenberg section in order to reconstruct a floating timescale using cyclostratigraphic methods and to investigate paleoclimatic dynamics using selected elemental ratios. Samples were measured as a powder covered with Chemplex film on a Bruker S1 Titan 800 portable XRF at the University of Münster with the following settings: 40 kV, 20 mA, no filters, 75 s. Spectra were deconvoluted in Bruker Artrax software, and linearly calibrated using a set of 10 sedimentary standards of known composition and 11 calcite-quart mixtures. The composition of these standards is also included. Selected elemental ratios were tuned via the methods described in the accompanying manuscript, and are included in this dataset as well.

Tuned SiO2/CaO ratios of the Devonian Kellwasser Crisis interval (ca. 372 Ma) at Winsenberg, Germany

A total of 556 samples (3 cm average sample spacing) were collected from the 12 m long Winsenberg section in order to reconstruct a floating timescale using cyclostratigraphic methods and to investigate paleoclimatic dynamics using selected elemental ratios. Samples were measured as a powder covered with Chemplex film on a Bruker S1 Titan 800 portable XRF at the University of Münster with the following settings: 40 kV, 20 mA, no filters, 75 s. Spectra were deconvoluted in Bruker Artrax software, and linearly calibrated using a set of 10 sedimentary standards of known composition and 11 calcite-quart mixtures. The composition of these standards is also included. Selected elemental ratios were tuned via the methods described in the accompanying manuscript, and are included in this dataset as well.

Tuned TiO2/Al2O3 ratios of the Devonian Kellwasser Crisis interval (ca. 372 Ma) at Winsenberg, Germany

A total of 556 samples (3 cm average sample spacing) were collected from the 12 m long Winsenberg section in order to reconstruct a floating timescale using cyclostratigraphic methods and to investigate paleoclimatic dynamics using selected elemental ratios. Samples were measured as a powder covered with Chemplex film on a Bruker S1 Titan 800 portable XRF at the University of Münster with the following settings: 40 kV, 20 mA, no filters, 75 s. Spectra were deconvoluted in Bruker Artrax software, and linearly calibrated using a set of 10 sedimentary standards of known composition and 11 calcite-quart mixtures. The composition of these standards is also included. Selected elemental ratios were tuned via the methods described in the accompanying manuscript, and are included in this dataset as well.

Stable carbon and oxygen carbonate isotope ratios of the Devonian Kellwasser Crisis interval (ca. 372 Ma) at Winsenberg, Germany

A total of 152 samples (8 cm average sample spacing) were analysed for carbonate d13C in order to identify the two characteristic positive excursions associated with the Lower and Upper Kellwasser Events. Measurements on powdered samples weighing 120-150 μg were carried out on a ThermoScientific Delta V Plus mass spectrometer at the University of Münster, using an in-house standard (Kabonat-1; δ13C = 1.46‰, δ18O = -1.19‰) for calibration and an external standard (NBS-19; δ13C = 1.95‰, δ18O = -2.20‰) for long-term performance monitoring.

Tuned K2O/Al2O3 ratios of the Devonian Kellwasser Crisis interval (ca. 372 Ma) at Winsenberg, Germany

A total of 556 samples (3 cm average sample spacing) were collected from the 12 m long Winsenberg section in order to reconstruct a floating timescale using cyclostratigraphic methods and to investigate paleoclimatic dynamics using selected elemental ratios. Samples were measured as a powder covered with Chemplex film on a Bruker S1 Titan 800 portable XRF at the University of Münster with the following settings: 40 kV, 20 mA, no filters, 75 s. Spectra were deconvoluted in Bruker Artrax software, and linearly calibrated using a set of 10 sedimentary standards of known composition and 11 calcite-quart mixtures. The composition of these standards is also included. Selected elemental ratios were tuned via the methods described in the accompanying manuscript, and are included in this dataset as well.

Depth levels and associated (floating) age of SiO2/CaO depth record of the Devonian Kellwasser Crisis interval (ca. 372 Ma) at Winsenberg, Germany

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