Wortmann Ulrich G.

wortman-in the field
Associate Chair

University of Toronto
Department of Earth Sciences

22 Russel 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 a 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

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.
 
 
 
 
 
 
 
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