Carbon dioxide concentrations in the atmosphere (pCO2) play a key role in the Earth’s climate dynamics. Quantifying pCO2 in the geological record can offer context for evaluating the direction and magnitude of climate change, and aid in a better understanding of evironmental responses and feedback mechanisms associated with increasing greenhouse gas release.
A recently developed method utilizes the isotopic composition of phytane as a pCO2 proxy. Phytane is one of the most abundantly available phytoplanktonic biomarkers and spatially and temporally ubiquitous. It therefore has the potential to generate long-term and high resolution pCO2 reconstructions based on a single proxy preserved in the Mesozoic record - a vast advantage above e.g., species- specific biomarkers (e.g. alkenones) and the leaf stomatal index.
The Early Jurassic (~201 - 174 Ma) was marked by major paleoenvironmental and climatic events, namely the end-Triassic mass extinction (ETE) and the Toarcian oceanic anoxic event (T-OAE). While these event intervals are well studied, information on the time interval bracketed by these events, comprising some 18 Ma years, is comparatively scarse. Geochemical records suggest changes in the global carbon cycle, frequent development of organic matter preservation intervals, climatic hot and cold snaps and oceanographic changes - however, there is no hollistic understanding of the secular evolution of the Early Jurassic paleoenvironment and climate following the ETE and leading up to the T-OAE.
This project is aiming to reconstruct atmospheric CO2 throughout Early Jurassic key intervals, such as the Sinemurian-Pliensbachain boundray, in order to contextualize climatic events and distinguish between and the causal mechanisms driving climatic shifts such as changing Carbon dioxide concentrations vs paleogeographic and oceanographic chages.
Ph.D. (Earth Sciences), Oxford University, UK
M.Sc. (Geology). Heidelberg University, Germany
B.Sc. (Georessources Management), RWTH Aachen, Germany
Al-Suwaidi, A.H., Ruhl, M., Jenkyns, H.C., Damborenea, S. E., Manceñido, M. O., Condon, D. J., Angelozzi, G. N., Kamo, S. L., Storm, M. and Riccardi, A. C. (2022): New age constraints on the Lower Jurassic Pliensbachian–Toarcian Boundary at Chacay Melehue (Neuquén Basin, Argentina). Sci Rep 12, 4975.
Ruhl M., Hesselbo S.P., Al-Suwaidi A., Jenkyns H.C., Damborenea S.E., Manceñido M., Storm M.S., Mather T., Riccardi A. (2020): On the Onset of Central Atlantic Magmatic Province (CAMP) Volcanism, Environmental and Carbon-Cycle Change at the Triassic–Jurassic Transition (Neuquén Basin, Argentina). Earth-Science Reviews 208:103229.
Storm M.S., Hesselbo S.P., Jenkyns H.C., Ruhl R., Ullmann C.V., Xu W., Leng M., Riding R.B., Gorbanenko O. (2020): Orbital pacing and secular evolution of the Early Jurassic carbon cycle. PNAS 117(8): 3974.
Wilmsen M., Storm M.S., Fürsich F.T., Majidifarad M.R., Schlagintweit F. & Hart M.B. (2018): The mid-Cretaceous Debarsu Formation (Upper Albian–Middle Turonian) of Central Iran: depositional environment, palaeogeography, and sequence stratigraphic signicance. Facies 64(4).
Xu W., Ruhl M., Jenkyns H.C., Leng M.J., Huggett J.M., Minisini D., Ullmann C.V., Riding J.B., Weijers J.W., Storm M.S., Percival L.M., Tosca N.J., Idiz E.F., Tegelaar E.W., Hesselbo S.P. (2018): Evolution of the Early Jurassic Toarcian carbon-cycle and global climatic controls on local sedimentary processes (Cardigan Bay Basin, UK). Earth and Planetary Science Letters 484: 396 – 411.
Ruhl M., Hesselbo S.P., Hinnov L., Jenkyns H.C., Xu W., Riding J.B., Storm M.S., Minisini D., Ullmann C.V. (2016): Astronomical constraints on the duration of the Early Jurassic Pliensbachian Stage and global climatic fuctuations. Earth and Planetary Science Letters: 455, 149 – 165.
Percival L.M.E, Cohen A.S., Davies, A.K., Dickson A.J., Hesselbo S.P., Jenkyns H.C., Leng M.J., Mather T.A., Storm M.S., Xu W. (2016): Osmium isotope evidence for two pulses of increased continental weathering linked to Early Jurassic volcanism and climate change. Geology: 44 (9), Pages 759 – 762.
Percival L.M.E., Witt M.L.I., Mather T.A., Hermoso M., Jenkyns H.C., Hesselbo S.P., Al-Suwaidi A.H., Storm M.S., Xu W., Ruhl M. (2015): Globally enhanced mercury deposition during the end-Pliensbachian extinction and Toarcian OAE: A link to the Karoo Ferrar Large Igneous Province. Earth and Planetary Science Letters, Volume 428, 15 October 2015, Pages 267–280.
Wilmsen M., Storm M., Fürsich F.T. & Majidifarad M.R. (2013): Upper Albian and Cenomanian (Cretaceous) ammonites from the Debarsu Formation (Yazd Block, Central Iran). Acta Geologica Polonica, Volume 63, Issue 4, Pages 489 – 513.