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Wortmann Ulrich G.

wortman-in the field
Associate Professor

University of Toronto
Department of Earth Sciences

22 Ursula Franklin St., Toronto
Ontario, Canada M5S 3B1

Office#: ESC3127
Tel.:  416 978 7084
Fax.: 416 978 3938

e-mail: uli.wortmann@utoronto.ca


My research interests straddle marine geology, paleoceanography, and geomicrobiology. I am interested in the global interplay of biology, chemistry, and physics on various timescales. Investigation of these tightly coupled systems requires an interdisciplinary approach, involving a multitude of methods. Stable isotope geochemistry and numerical modeling are versatile tools in Earth System Science and the cornerstone of my own research. I currently serve on the council of the  Centre for Global Change Science, and as the University of Toronto’s Liason to the Canadian Consortium for Ocean Drilling (which represents Canada within the international  IODP-Program.

Selected Publications

For a complete list of my publications click here

Large-scale ocean deoxygenation during the Paleocene-Eocene Thermal Maximum, Weiqi Yao1, Adina Paytan, Ulrich G. Wortmann. Science 2018 http://science.sciencemag.org/content/early/2018/07/18/science.aar8658
Palaeomagnetic time and space constraints of the Early Cretaceous Rhenodanubian Flysch zone (Eastern Alps).
E Dallanave, U Kirscher, J Hauck, R Hesse, V Bachtadse, UG Wortmann
Geophysical Journal International 213 (3), 1804-1817
Multicentennial record of Labrador Sea primary productivity and sea-ice variability archived in coralline algal barium. Phoebe Chan, Jochen Halfar, Walter Adey, Steffen Hetzinger, Thomas Zack, GWK Moore, UG Wortmann, Branwen Williams, Alicia Hou. Nature Communications, 2017.
An evaporite-based high-resolution sulfur isotope record of Late Permian and Triassic seawater sulfate. Stefano M Bernasconi, Irene Meier, Stephan Wohlwend, Peter Brack, Peter A Hochuli, Hansruedi Bläsi, Ulrich G Wortmann, Karl Ramseyer. Geochimica et Cosmochimica Acta, 204, 2017.
Quantifying the volcanic emissions which triggered Oceanic Anoxic Event 1a and their effect on ocean acidification KW Bauer, RE Zeebe, UG Wortmann. Sedimentology 64 (1), 204-214
A new model of the formation of Pennsylvanian iron carbonate concretions hosting exceptional soft‐bodied fossils in Mazon Creek, Illinois.  S Cotroneo, JD Schiffbauer, VE McCoy, UG Wortmann, SAF Darroch, Y Peng, M Laflamme. Geobiology 2016
A revised seawater sulfate oxygen isotope record for the last 4 Myr
S Markovic, A Paytan, H Li, UG Wortmann
Geochimica et Cosmochimica Acta 175, 239-251. 2016
S. Markovic, A. Paytan, and U. G. Wortmann (2015): Pleistocene sediment offloading and the global sulfur cycle. Biogeosciences, 12:3043–3060, http://www.biogeosciences.net/12/3043/2015/, DOI:10.5194/bg-12-3043-2015
Wortmann UG & Paytan A (2012): Rapid Variability of Seawater Chemistry Over the Past 130 Million Years. Science337(6092):334-336.
Li L, Lollar BS, Li H, Wortmann UG & Lacrampe-Couloume G (2012): Ammonium stability and nitrogen isotope fractionations for NH4+-NH3 (aq)-NH3 (gas) systems at 20-70 °C and pH of 2-13: Applications to habitability and nitrogen cycling in low-temperature hydrothermal systems. Geochimica et Cosmochimica Acta84(0):280 – 296.
DeBond N, Oakes RL, Paytan A & Wortmann UG (2012): Early Aptian carbon and sulphur isotope signatures at ODP Site 765. Isotopes in Environmental and Health Studies48(1):180-194.
Wortmann UG & Chernyavsky BM (2011): The significance of isotope specific diffusion coefficients for reaction-transport models of sulfate reduction in marine sediments. Geochimica et Cosmochimica Acta75(11):3046 – 3056. – Doi: 10.1016/J.Gca.2011.03.007.
Eckert T, Brunner B, Edwards EA & Wortmann UG (2011): Microbially mediated re-oxidation of sulfide during dissimilatory sulfate reduction by Desulfobacter latus. Geochimica et Cosmochimica Acta75(12):3469 – 3485. – Doi: 10.1016/J.Gca.2011.03.034.
Williams B, Halfar J, Steneck RS, Wortmann UG, Hetzinger S, Adey W, Lebednik P & Joachimski M (2011): Twentieth century d13C variability in surface water dissolved inorganic carbon recorded by coralline algae in the northern North Pacific Ocean and the Bering Sea. Biogeosciences8(1):165–174.
Hetzel A, Boettcher ME, Wortmann UG & Brumsack HJ (2009): Paleo-redox conditions during OAE 2 reflected in Demerara Rise sediment geochemistry (ODP Leg 207). Palaeogeography, Palaeoclimatology, Palaeoecology273(3 – 4):302 – 328.
Groecke D & Wortmann U (ed.) (2008): Investigating climates, environments and biology using stable isotopes. Elsevier, vol. 266. Palaeogeography, Palaeoclimatology Palaeoecolog, Special Volume.
Wortmann UG & Chernyavsky BM (2007): Effect of evaporite deposition on Early Cretaceous carbon and sulphur cycling. NATURE446:654–656.
Wortmann UG, Chernyavsky B, Bernasconi SM, Brunner B, Boettcher ME & Swart PK (2007): Oxygen isotope biogeochemistry of pore water sulfate in the deep biosphere: Dominance of isotope exchange reactions with ambient water during microbial sulfate reduction (ODP Site 1130). GEOCHIMICA ET COSMOCHIMICA ACTA71:4221–4232.
Wortmann UG, Herrle JO & Weissert H (2004): Altered carbon cycling and coupled changes in Early Cretaceous weathering patterns: Evidence from integrated carbon isotope and sandstone records of the western Tethys. EARTH AND PLANETARY SCIENCE LETTERS220:69–82.
Wortmann UG, Weissert H, Funk H & Hauck J (2001): Alpine plate kinematics revisited: The Adria problem. TECTONICS20:134–147.
Wortmann UG, Bernasconi SM & Bottcher ME (2001): Hypersulfidic deep biosphere indicates extreme sulfur isotope fractionation during single-step microbial sulfate reduction. GEOLOGY29:647–650.
Wortmann UG, Hesse R & Zacher W (1999): Major-element analysis of cyclic black shales: Paleoceanographic implications for the Early Cretaceous deep western Tethys. PALEOCEANOGRAPHY14:525–541.