Dr Micha Ruhl

Foto_M

Shell Postdoctoral Researcher Sedimentology/ Stratigraphy/ Geochemistry/ Diagenesis of Mudrocks

Email: Micha.Ruhl@earth.ox.ac.uk

Research Interests

I am a geologist/palaeoclimatologist, with a background in (organic) geochemistry, stratigraphy and sedimentology, interested in studying deep-time environmental and climatic perturbations and changes in the depositional environment and their link to internal and external forcing mechanisms of the Earth system. I am specifically interested in (1) changes in global geochemical cycles and their link to (major) volcanic events (LIPs) and (global) climatic perturbations, (2) changes in depositional environments on local, regional and global scales and their link to palaeoceanographic and climatic change and the formation of source rocks, (3) astrochronology: understanding timing of events observed in sedimentary archives.

Current Research

In the Oxford-Shell Mudrock Observatory project I use organic/inorganic geochemical and sedimentological (core description/SEM) methods to study Mesozoic sedimentary records often marked by massive carbon burial and often recognized as (global) Oceanic Anoxic Events (OAEs). In particular I study:

  • The Local and regional, intra-basinal, depositional environment of the Cenomanian-Turonian Eagle Ford Formation (comprising OAE2) and its link to global palaeoceanographic, climatic and volcanic perturbations.
  • The Toarcian OAE in the marine (Mochras-core & Yorkshire coastal sections (UK) and Neuquen Basin (Argentina)) and continental (Sichuan Basin, China) realms, to understand the global significance of early Toarcian observations known from the European realm.
  • Changes in the local and regional, intra-basinal, depositional environment in the Lower Saxony Basin (Germany), leading to deposition of the Posidonia Shale.
  • Lower and middle Jurassic stratigraphy in the Neuquen Basin, Argentina.
  • Astronomical calibration of the lower Jurassic in the marine Mochras core.
  • Triassic-Jurassic boundary events in European sections and in the Argentinian Neuquen Basin.

Past:

  • Nordic Center for Earth Evolution (NordCEE), University of Copenhagen, Denmark (2010-2012)
  • TNO Built, Environment & Geosciences, Netherlands (2010)
  • Laboratory of Palaeobotany and Palynology/ Palaeoecology/ Geochemistry, Utrecht University, Netherlands (2006-2010)

Publications

Xu, W., Ruhl, M., Jenkyns, H., Hesselbo, S.P., Riding, J.B., Selby, D., Naafs, B.D.A., Weijers, J.W.H., Pancost, R.D., Tegelaar, E.W. and Idiz, E.F. (2017) Carbon sequestration in an expanded lake system during the Toarcian oceanic anoxic event. Nature Geoscience, DOI: 10.1038/NGEO2871

Jenkyns, H.C.,Dickson, A.J., Ruhl, M. and van den Boorn, S.H.J.M (2017) Basalt–seawater interaction, the Plenus Cold Event, enhanced weathering and geochemical change: deconstructing Oceanic Anoxic Event 2 (Cenomanian–Turonian, Late Cretaceous). Sedimentology, 64, 16-43, doi: 10.1111/sed.12305

Xu, W., Ruhl, M., Hesselbo, S.P., Riding, J.B. and Jenkyns, H., 2017. Orbital pacing of the Early Jurassic carbon cycle, black-shale formation and seabed methane seepage. Sedimentology (2017) 64, 127–149, doi: 10.1111/sed.12329

Robnison, S.A., Ruhl, M., Astley, D. L.,  Naafs, B.D.A., Farnsworth, A.J., Bown, P.R., Jenkyns, H.C., Lunt, D.J., O’Brien, C., Pancost, R. and Markwick, P.J. (2017) Early Jurassic North Atlantic sea-surface temperatures from TEX86 palaeothermometry. Sedimentology, 64, 215-230, doi: 10.1111/sed.12321

Ruhl, M., Hesselbo, S.P., Hinnov, L., Jenkyns, H.C., Xu, W., Riding, J.B., Storm, M., Minisini, D., Ullmann, C.V. and Leng, M.J (2016). Astronomical constraints on the duration of the Early Jurassic Pliensbachian Stage and global climatic fluctuations. Earth and Planetary Science Letters, 455, 149–165.

Korte, C., Hesselbo, S.P., Ullmann, C.V., Dietl, G., Ruhl, M., Schweigert, G. and Thibault, N. (2015) Jurassic climate mode governed by ocean gateway. Nature Communications. DOI: 10.1038/ncomms10015

Hüsing, S., Beniest, A., van der Boon, A., Deenen, M.H.L., Ruhl, M., Krijgsman, W. (2014) Magnetostratigraphy of the Lower Jurassic marine successions at St. Audrie’s Bay and East Quantoxhead (Hettangian-Sinemurian; Somerset, UK). Palaeogeography, Palaeoclimatology, Palaeoecology, 403, 43–56 .

Ullmann, C., Hesselbo, S., Ruhl, M., Thibault, N, Korte, C. (2014) Effect of a Jurassic Oceanic Anoxic Event on belemnite ecology and evolution. Proceedings of the National Academy of Sciences USA, 111 (28), pp. 10073-10076

Hesselbo, S. Bjerrum, C.J., Hinnov, L., MacNiocaill, C., Miller, K., Riding, J., Van de Schootbrugge, B. and the Mochras Revisited Science Team (2013) Mochras Revisited: A New Global standard for Early Jurassic Earth History. Scientific Drilling 16, pp. 81–91

Hillebrandt, A.v., Krystyn, L., Kurschner, W.M., Bonis, N.R., Ruhl, M., Richoz, S., Schobben, M. A. N., Urlichs, M., Bown, P.R., Kment, K., McRoberts, C.A., Simms, M., Tomasových, A. (2013) The Global Stratotype Sections and Point (GSSP) for the base of the Jurassic System at Kuhjoch (Karwendel Mountains, Northern Calcareous Alps, Tyrol, Austria). Episodes, 36 (3), 162-198

Dahl. T.W., Ruhl, M., Hammarlund, E.U., Canfield, D.E., Rosing, M.T., Bjerrum, C.J. (2013) Tracing euxinia by molybdenum concentrations in sediments using handheld x-ray fluorescence spectroscopy (HH-XRF). Chemical Geology, 360, pp. 241-251

Ruhl, M., Bonis N.R., Reichart, G.-J., Sinninghe Damsté, J.S., Kürschner, W.M. (2011) Atmospheric methane injection caused end-Triassic mass extinction. Science, pp. 333, 430

Ruhl, M. & Kürschner, W.M. Multiple phases of carbon-cycle disturbance from Large Igneous Province formation at the Triassic-Jurassic transition. Geology 39 (5), 431-434 (2011).

Deenen, M.H.L., Krijgsman, W., Ruhl, M. (2011) The quest for E23r at Partridge Island (Bay of Fundy): CAMP emplacement post-dating the end-Triassic extinction event in Canada. Canadian Journal of Earth Sciences, 48, 1282-1291 .

Ruhl, M., Deenen, M.H.L., Abels, H.A., Bonis, N.R., Krijgsman, W., Kürschner, W.M. (2010) Astronomical constraints on the duration of the early Jurassic Hettangian stage and recovery rates following the end-Triassic mass extinction (St. Audrie’s Bay/ East Quantoxhead, UK). Earth and Planetary Science Letters 295 (1-2): 262-276 .

Bonis, N.R., Ruhl, M., Kürschner, W.M. (2010) Climate change driven black shale deposition during the end-Triassic in the western Tethys. Palaeogeography, Palaeoclimatology, Palaeoecology 290 (1-4): 151-159 .

Bonis, N.R., Ruhl, M. and Kürschner, W.M. (2010) Milankovitch-scale palynological turnover across the Triassic-Jurassic transition at St. Audrie’s Bay, SW UK. Journal of the Geological Society, London 167: 877-888.

Ruhl, M., Veld, H., Kürschner, W.M. (2010) Sedimentary organic matter characterization of the Triassic–Jurassic boundary GSSP at Kuhjoch (Austria). Earth and Planetary Science Letters, 292 (1-2): 17-26 .

Deenen, M.H.L., Ruhl, M., Bonis, N.R., Krijgsman, W., Kürschner, W.M., Reitsma, M. and Bergen, M.J. v. (2010) A new chronology for the end-Triassic mass extinction. Earth and Planetary Science Letters, 291 (1-4): 113-125 .

Ruhl, M., Kürschner, W.M., Krystyn, L. (2009) Triassic-Jurassic organic carbon isotope stratigraphy of key sections in the western Tethys realm (Austria). Earth and Planetary Science Letters, 281 (3-4): 169-187 .

Hillebrandt, A. v., Krystyn, L., Kürschner, W.M., Bonis, N.R., Ruhl, M., Urlichs, M., with contributions by Bown, P., Kment, K., McRoberts, C., Simms, M., Tomasovych, A. (2007) A candidate GSSP for the base of the Jurassic in the Northern Calcareous Alps (Kuhjoch section; Karwendel Mountains, Tyrol, Austria). International Subcommission on Jurassic Stratigraphy Newsletter, 34(1), 2-20 .

Book/-chapter

Ruhl., M. Carbon cycle changes during the Triassic-Jurassic transition. PhD-thesis, LPP Contributions series, 28, 151p, Utrecht, (2010).

Koho, K.A., de Stigter, H.C., Kouwenhoven, T.J., Ruhl, M., Kuijpers, A. and Van der Zwaan, G.J. The response of benthic foraminifera to differential sedimentary regimes in the lower Nazaré Canyon since the last deglaciation. Geologica Ultraiectina 286 (Chapter 6): 93-107 (2008).

Commissioned report

Verreussel, R.M.C.H., Abbink, O.A., Cremer, H., Donders, T.H., Garming, J.F.L., Guasti, E., Van Hoof, T.B., Kirchholtes, R.P.J., Ruhl, M., 2010. TNO-report 034-UT-2010-00970. Biogenic silica particle based stratigraphy for the Rotliegend in the Netherlands. BIOSIL III Project: Final report.

Published abstracts

Ruhl, M., Bjerrum, C.J., Canfield, D.E., Frei, R. Triassic-Jurassic marine anoxia in response to massive carbon release from CAMP? Geophysical Research Abstracts 14, EGU2012-11595 (2012).

Ruhl, M., Ullmann, C.V., Mette, W., Korte, C. Carbon-cycle disturbances and environmental change preceding the end-Triassic mass extinction. Geophysical Research Abstracts 14, EGU2012-13359 (2012).

Ruhl, M., Bjerrum, C., Frei, R., Korte, C., 2011. A Novel Proxy Links CAMP Volcanism with End-Triassic Mass Extinction and Early Jurassic Evolution. GOLDSCHMIDT CONFERENCE, Mineralogical Magazine 75 (3), 2011.

Ruhl, M. & Kürschner, W.M., 2010. Multiple late Triassic carbon cycle perturbations preceding intensified volcanic activity in the Central Atlantic Magmatic Province. EGU GENERAL ASSEMBLY, Geophysical Research Abstracts 10: EGU2010-7214.

Deenen, M.H.L., Ruhl, M., Bonis, N.R., Krijgsman, W., Kürschner, W.M. & Van Bergen, M.J., 2010. A new chronology for the end-Triassic mass extinction. EGU GENERAL ASSEMBLY, Geophysical Research Abstracts 10: EGU2010-9400.

Ruhl, M., Bonis, N.R., Deenen, M.H.L., Abels, H.A., Krijgsman, W. & Kurschner, W.M., 2010. Astronomical control on climate and vegetation history at the Triassic-Jurassic transition. EGU GENERAL ASSEMBLY, Geophysical Research Abstracts 10: EGU2010-7199.

Ruhl, M., Bonis, N.R., Reichart, G.-J., Sinninghe Damsté, J.S. & Kürschner, W.M., 2010. Atmospheric methane injection caused end-Triassic mass extinction. EGU GENERAL ASSEMBLY, Geophysical Research Abstracts 10: EGU2010-7212.

Ruhl, M., Kürschner, W.M. & Reichart, G.-J., 2009. Global carbon cycle turnover at the Triassic-Jurassic boundary. GOLDSCHMIDT CONFERENCE, Geochimica et Cosmochimica Acta 73, (13-1): A1066-A1138.

Ruhl, M., Bonis, N.R. & Kürschner, W.M., 2008. Stomatal frequency analysis and carbon isotope stratigraphy from the Germanic Basin: Changing CO2 levels during the end-Triassic. EGU GENERAL ASSEMBLY, Geophysical Research Abstracts 10: EGU2008-A-02506.

Ruhl, M., Kürschner, W.M., Reichart, G.-J. & Krystyn, L., 2008. High resolution carbon isotope data of Triassic-Jurassic key sections in the western Tethys realm. EGU GENERAL ASSEMBLY, Geophysical Research Abstracts10: EGU2008-A-02083.

Ruhl, M., Kürschner, W.M., Reichart, G.-J. & Krystyn, L., 2007. Detailed carbon isotope analysis of Triassic-Jurassic key sections in the western Tethys realm. THE GLOBAL TRIASSIC CONFERENCE, (Albequerque, USA): New Mexico Museum Natural History and Science Bulletin 41.

Koho, K.A., de Stigter, H.C., Kouwenhoven, T.J., Ruhl, M., Kuijpers, A. & Van der Zwaan, G.J., 2007. The response of canyon-fan benthic foraminifera to changing sedimentary regimes since the Last Glacial Maximum. EGU GENERAL ASSEMBLY, Geophysical Research Abstracts 9: EGU2007-A-08791.

Ruhl, M., Kürschner, W.M. & Krystyn, L., 2006. New detailed carbon isotope analysis of sedimentary organic matter from the classical Triassic-Jurassic Kendlbachgraben (Austria). EGU GENERAL ASSEMBLY, Geophysical Research Abstracts 8: EGU2006-A-07438.

Invited talks

Ruhl, M., Bjerrum, C., Frei, R., Korte, C., 2011. A Novel Proxy Links CAMP Volcanism with End-Triassic Mass Extinction and Early Jurassic Evolution. GOLDSCHMIDT CONFERENCE, Mineralogical Magazine, Vol. 75 (3), 2011.

Ruhl, M., 2009. Carbon cycle changes during the Triassic-Jurassic transition. NETHERLANDS SCHOOL OF SEDIMENTARY GEOLOGY CONFERENCE, (Amsterdam, Netherlands).

Ruhl, M., 2009. Carbon isotope events at the Triassic-Jurassic transition. ADVANCES IN TRIASSIC PALEOBIOLOGY CONFERENCE, (Winterswijk, Netherlands).