Mitarbeiter
Dr. Christopher Siebert
GEOMAR Helmholtz Zentrum für Ozeanforschung Kiel
FE Paläo-Ozeanographie
Forschungsbereich 1: Ozeanzirkulation und Klimadynamik
Adresse:
Wischhofstrasse 1-3. D-24148 Kiel
Büro:
Raum: 8/D-133
Telefon: +49 431 600-2252
E-Mail: csiebert(at)geomar.de
Leitung Reinraum und MCICPMS Einrichtungen der Paleo-Ozeanographie
Wissenschaftliche Interessen
Ich beschäftige mich mit der Entwicklung und der Anwendung neuer "schwerer" stabiler Isotopensysteme als Indikatoren (Proxies) für biogeochemische Prozesse und Biomarker in der Medizin.
Hierbei habe ich die folgende Schwerpunkte:
- Entwicklung von Isotopen-Biomarkern für medizinische Diagnose
- Marine sedimentäre Prozesse, Land/Ozean Interaktion
- Oxygen Minumum Zonen und ihre zeitliche Entwicklung
- Entwicklung von neuen Methoden in der Massenspektrometrie; Verständnis von instrumenteller Massenfraktionierung in der Massenspektrometrie
Eine Auswahl laufender Projekte:
- Untersuchung der Intensität und Ausbreitung der "oxygen minimum zone" (OMZ) vor der Küste von Peru seit dem Pliozän( Molybdän-Isotopie, Eisen Spezation)
- Entwicklung und Anwendung von Barium Isotopen als (Paleo-) Wassermassen-Proxy, inbesondere für den Eintrag von Frischwasser in die Ozeane; Barium Isotope als Prozess-Indikatoren in Barit-Entstehung
- Transfer: Entwicklung von schweren stabilen Isotopen als Biomarker für Oxidativen Stress und Krebs in der Humanmedizin
- Untersuchung des Zusammenhangs von Plasma Temperatur und instrumenteller Massenfraktionierung
Ausgewählte Publikationen
Yu, Y., Hathorne, E., Siebert, C., Gutjahr, M., Fietzke, J., Frank, M. (2024) Unravelling instrumental mass fractionation of MC-ICP-MS using neodymium isotopes, Chemical Geology, Vol. 662, 10.1016/j.chemgeo.2024.122220
Münker, C., Wombacher, F., Siebert, C. (2023) Cambrian ocean floor crust preserved in the Takaka Terrane, New Zealand, New Zealand Journal of Geology and Geophysics, Vol. 66, Issue 3, 405-427, 10.1080/00288306.2023.2197239
Scholz, F., Cheng, J., Zhang, Z.L,, Vosteen, P., Siebert, C., Frank, M. (2023) Benthic-pelagic coupling and isotopic fractionation of barium in Kiel Bight, SW Baltic Sea, Frontiers in Marine Science, Vol.10, 10.3389/fmars.2023.1101095
Yu, Y., Hathorne, E., Siebert, C., Felis, T., Rajendran, C.P., Frank, M. (2022) Monthly resolved coral barium isotopes record increased riverine inputs during the South Asian summer monsoon, Geochimica et Cosmochimica Act, Vol. 329, 152-167, 10.1016/j.gca.2022.05.001
Eroglu, S., Scholz, F., Salvatteci, R., Siebert, C., Schneider, R., Frank, M. (2021) The impact of postdepositional alteration on iron- and molybdenum-based redox proxies, Geology, Vol. 49, Issue 12, 1411-1415, 10.1130/G49291.1
Cao, Z.M., Rao, X.T., Yu, Y., Siebert, C., Hathorne, E.C., Liu, B., Wang, G.Z., Lian, E.G., Wang, Z.B., Zhang, R.F., Gao, L., Wei, G.J., Yang, S.Y., Dai, M.H., Frank, M. (2021) Stable Barium Isotope Dynamics During Estuarine Mixing, Geophysical Research Letters, Vol. 48, Issue 19, 10.1029/2021GL095680
Siebert, C., Scholz, F., Kuhnt, W. (2021) A new view on the evolution of seawater molybdenum inventories before and during the Cretaceous Oceanic Anoxic Event 2, Chemical Geology, Vol. 582, 10.1016/j.chemgeo.2021.120399
Yu, Y., Siebert, C., Fietzke, J., Goepfert, T., Hathorne, E., Cao, Z.M., Frank, M. (2020) The impact of MC-ICP-MS plasma conditions on the accuracy and precision of stable isotope measurements evaluated for barium isotopes, Chemical Geology, Vol. 549, 10.1016/j.chemgeo.2020.119697
Eroglu, S, Scholz, F, Frank, M, Siebert, C (2020) Influence of particulate versus diffusive molybdenum supply mechanisms on the molybdenum isotope composition of continental margin sediments, Geochimica et Cosmochimica Acta, Vol. 273, 51-69
Scholz, F., Baum, M., Siebert, C., Eroglu, S., Dale, A.W., Naumann, M., Sommer, S. (2018) Sedimentary molybdenum cycling in the aftermath of seawater inflow to the intermittendly euxinic Gotland Deep, Central Baltic Sea, Chemical Geology, 491, 27-38
Yang, J., Barling, J., Siebert, C., Fietzke, J., Stephens, E., Halliday, A. (2017) The molybdenum isotopic compositions of I-, S- and A-type granitic suites, Geochimica et Cosmochimica Acta, 205, 168-186
Scholz, F., Siebert, C., Dale, A.W., Frank, M., (2017) Intense molybdenum accumulation in sediments underneath a nitrogenous water column and implications for the reconstruction of paleo-redox conditions based on molybdenum isotopes, Geochimica et Cosmochimica Acta, 213, 400-417
Liang, H., Halliday, A.N., Siebert, C., Fitton, J.G., Burton, K.W., Wang, K-L., Harvey, J., (2017) Molybdenum isotope fractionation in the mantle, Geochimica et Cosmochimica Acta, 199, 91-111
Baronas, J.J., Hammond, D.E., McManus, J., Wheat, C.G., Siebert, C. (2017) A global Ge isotope budget, Geochimica et Cosmochimica Acta, 203, 265-283
Cao, Z., Siebert, C., Hathorne, E.C., Minhan, D., Frank, M. (2016) Constraining the oceanic barium cycle with stable barium isotopes, Earth and Planetary Science Letters, 434, 1-9
Abraham, K., Barling, J., Siebert, C., Belshaw, N., Gall, L., Halliday, A.N. (2015) Determination of mass-dependent variations in tungsten stable isotope compositions of geological reference materials by double-spike and MC-ICPMS, Journal of Analytical Atomic Mass Spectrometry, DOI: 10.1039/c5ja00210a
Ventura, G.T., Gall, L., Siebert, C., Prytulak, J., Szatmari, P., Hürlimann, M., Halliday, A.N. (2015) The stable isotope composition of vanadium, nickel, and molybdenum in crude oils, Applied Geochemistry, 59, 104-117
Dausmann, V., Frank, M., Siebert, C., Christl, M., Hein, J.R. (2015) The evolution of climatically driven weathering inputs into the western Arctic Ocean since the late Miocene: Radiogenic isotope evidence, Earth and Planetary Sciences Letters, 419, 111-124
Yang, J., Siebert, C., Barling, J., Savage, P., Liang, Y.-H., Halliday, A.N. (2015) Absence of molybdenum isotope fractionation during magmatic differentiation at Hekla volcano, Iceland, Geochimica et Cosmochimica Acta, 162, 126-136
Siebert, C., Pett-Ridge, J.C., Opfergelt, S., Guicharnaud, R.A., Halliday, A.N., Burton, K.W. (2015) Molybdenum isotope fractionation in soils: Influence of redox conditions, organic matter, and atmospheric inputs, Geochimica et Cosmochimica Acta, 162, 1-24
Gall, L., Williams, H.M., Siebert, C., Halliday, A.N., Herrington, R.J., Hein, J.R. (2013) Nickel isotopic compositions of ferromanganese crusts and the constancy of deep ocean inputs and continental weathering effects over the Cenozoic, Earth and Planetary Sciences Letters, 375, 148-155
Greber, N.D., Siebert, C., Naegler, T.F., Pettke, T. (2012) δ98/95Mo values and Molybdenum Concentration Data for NIST SRM 610, 612 and 3134: Towards a Common Protocol for Reporting Mo Data, Geostandards and Geoanalytical Research, 36 (3), 291
Gall, L., Williams, H.M., Siebert, C., Halliday, A.N. (2012) Determination of mass-dependent variations in nickel isotope compositions using double spiking and MC-ICPMS, Journal of Analytical Atomic Mass Spectrometry, 27,137
Opfergelt S., Georg, R.B., Burton K.W., Guicharnaud, R., Siebert C., Gislason S.R., Halliday A.N. (2010) Silicon Isotopes in allophane as a proxy for mineral formation in volcanic soils, Applied Geochemistry, 26, S115
Siebert C., Ross A., McManus J. (2006), Germanium isotope measurements of high-temperature geothermal fluids using double-spike hydride generation MC-ICP-MS, Geochimica et Cosmochimica Acta 70 (15), 3986-3995
Poulson R.L., Siebert C., McManus J., Berelson W.M. (2006), Authigenic molybdenum isotope signatures in marine sediments, Geology, 34 (8), 617-620
Siebert C., McManus J., Bice A., Poulson R., Berelson W.M. (2006), Molybdenum isotope signatures in continental margin marine sediments, Earth and Planetary Science Letters, 241 (3-4), 723-733
Siebert C., Kramers J.D., Meisel T., Morel P., Nägler T.F. (2005), PGE, Re-Os, and Mo isotope systematics in Archean and early Proterozoic sedimentary systems as proxies for redox conditions of the early Earth, Geochimica et Cosmochimica Acta, 69 (7), 1787-1801
Siebert, C., Nägler, T.F., von Blanckenburg, F., and Kramers, J.D. (2003), Molybdenum isotope records as potential new proxy for paleoceanography, Earth and Planetary Science Letters, 211 (3-4), 159-171
McManus, J., Nägler, T., Siebert, C., Wheat, C.G., and Hammond, D. (2002), Oceanic molybdenum isotope fractionation: Diagenesis and hydrothermal ridge flank alteration, Geochemistry Geophysics Geosytems, 3, Art. No. 1078, doi:10.1029/2002GC000356.
Siebert, C., Nägler, T.F., and Kramers, J.D. (2001), Determination of molybdenum isotope fractionation by double-spike multicollector inductively coupled plasma mass spectrometry, Geochemistry Geophysics Geosytems, 2, Art. No. 2000GC000124
Verkürzter Lebenslauf
2012-present: Wissenschaftler, GEOMAR, Helmholtz Zentrum für Ozean Forschung, Kiel, Germany
2010-2012: NERC Fellow, Department of Earth Sciences, University of Oxford, UK
2007-2010: Research Fellow, Department of Earth Sciences, University of Oxford, UK
2006: Research Associate, School of Earth and Space Exploration, Arizona State University, USA
2003-2005: SNF Fellow, College of Oceanic and Atmospheric Sciences, Oregon State University, USA
1999-2003: PhD, Institute of Geological Sciences, University of Berne, CH
