Large Lakes Observatory

Josef Werne

Associate Professor

Large Lakes Observatory
University of Minnesota
2205 E. 5th St.,
Research Laboratory Building 205
Duluth, MN 55812

Tel. (218) 726-7435

Fax: (218) 726-6979

email: jwerne at d.umn.edu

RESEARCH INTERESTS

• Organic and Stable Isotope Biogeochemistry.
• Sedimentary cycling of organic and inorganic sulfur and the sulfurization of organic matter.
• Biogeochemical isotope fractionation processes of C, H, O, N, and S.
• Molecular isotopic indicators of paleoclimate in sedimentary archives.
• Microbial geochemistry.

EDUCATION

Northwestern University, Ph.D.
Denison University, B.S.

COURSES TAUGHT

• CHEM 2212 Environmental Chemistry
• LIM 5004 Field Limnology
• LIM 5102 Chemical Limnology
• CHEM 5150 Organic and Stable Isotope Biogeochemistry

RECENT PUBLICATIONS
* denotes student/postdoc author

Powers*, L.A., J.P. Werne, E.C. Hopmans, J.S. Sinninghe Damsté, S. Schouten (In review) Applicability and calibration of the TEX86 paleothermometer in lakes. Submitted to Geochimica et Cosmochimica Acta.

Werne, J.P., D.J. Hollander, T.W. Lyons, E.C. Hopmans, S. Schouten, and J.S. Sinninghe Damsté (In review) Investigating pathways of diagenetic organic matter sulfurization using compound-specific sulfur isotope analysis. Submitted to Geochimica et Cosmochimica Acta

Castañeda*, I., Werne, J.P., Johnson, T., and Filley, T. (In review) Terrestrial plant biomarkers indicate variability in tropical East African vegetation during the Late Pleistocene and Holocene Submitted to Palaeogeography, Palaeoclimatology, Palaeoecology.

Donahue*, M., J.P. Werne, C. Meile (2007) The sulfur isotope signature of sulfate reduction in Cariaco Basin sediments: Modeling effects of fractionation and differential diffusion. Geochimica et Cosmochimica Acta. Submitted 3/07, accepted 7/07.

Castañeda*, I., Werne, J.P., Johnson, T.C. (2007) Wet/arid phases in the southeast African tropics since the Last Glacial Maximum. Geology. v. 35, no. 9, pp. 823-826.

Russell*, J., Werne, J.P. (2007) Technical Note: The Use of Solid Phase Extraction Chromatographic Columns in Fatty Acid Purification. Organic Geochemistry. v. 38, p. 48-51.

Powers*, L., T.C. Johnson, J.P. Werne, I. Castañeda*, E.C. Hopmans, J.S. Sinninghe Damsté, S. Schouten (2005) Large temperature variability in the southern African tropics since the Last Glacial Maximum. Geophysical Research Letters. 32, L08076, doi:10.1029/2004GL022014.

Werne, J.P., and J.S Sinninghe Damsté (2005) Mixed sources contribute to the molecular isotopic signature of methane-rich mud breccia sediments of Kazan mud volcano (Eastern Mediterranean). Organic geochemistry, v. 36, no. 1, pp. 13-27.

Werne, J.P. and D.J. Hollander (2004) Balancing supply and demand: Controls on carbon isotope fractionation in the Cariaco Basin (Venezuela) Younger Dryas to Present. Marine Chemistry. v. 92, no. 1-4, pp. 275-293.

Powers*, L., Werne, J.P., Johnson, T.C., Hopmans, E.C., Sinninghe Damste, J.S.S., and Schouten, S. (2004) Crenarchaeotal membrane lipids in lake sediments: a new paleotemperature proxy for continental paleoclimate reconstruction? Geology, v. 32, no. 7, p. 613-616.

Werne, J.P., T. Zitter, R.R. Haese, G. Aloisi, I. Bouloubassi, S. Heijs, A. Fiala-Medioni, R.D. Pancost, J.S. Sinninghe Damste, G. de Lange, L.J. Forney, J.C. Gottschal, J.-P. Foucher, J. Mascle, J. Woodside, and the MEDINAUT and MEDINETH Shipboard Scientific Parties. 2004. Life at cold seeps: A synthesis of ecological and biogeochemical data from Kazan mud volcano, eastern Mediterranean Sea. Chemical Geology, v. 205, no. 3-4, p. 367-390.

Werne, J.P., D.J. Hollander, T.W., Lyons, J.S. Sinninghe Damsté (2004) Organic sulfur biogeochemistry: Recent advances and future directions for organic sulfur research. In: Sulfur Biogeochemistry: Past and Present. J. Amend, K. Edwards, & T. Lyons, eds. GSA Special Paper 379, Ch. 9 pp. 135-150.

Werne, J.P., T.W. Lyons, D.J. Hollander, M.J. Formolo, J.S. Sinninghe Damsté (2003) Reduced sulfur in euxinic sediments of the Cariaco Basin: sulfur isotope constraints on organic sulfur formation. Chemical Geology v. 195, p. 159-179.

Lyons, T.W., J.P. Werne, and D.J. Hollander, R.W. Murray (2003) Contrasting sulfur geochemistry and Fe/Al and Mo/Al ratios across the last oxic-to-anoxic transition in the Cariaco Basin, Venezuela. Chemical Geology. v. 195, p. 131-157.

Sageman, B.B., A.E. Murphy, J.P. Werne, C.A. Ver Straeten, D.J. Hollander, and T. W. Lyons (2003) A tale of shales: the relative roles of production, decomposition, and dilution in the accumulation of organic-rich strata, Middle-Upper Devonian, Appalachian basin. Chemical Geology, v. 195, p. 229-273.

Werne, J.P., B.B. Sageman, T.W. Lyons, and D.J. Hollander (2002) An integrated assessment of a "type euxinic" deposit: Evidence for multiple controls on black shale deposition in the middle Devonian Oatka Creek Formation. American Journal of Science, v. 302, pp. 110-143.

Werne, J.P., M. Baas, J.S. Sinninghe Damsté (2002) Molecular isotopic tracing of carbon flow and trophic relationships in a methane-supported microbial community. Limnology & Oceanography v. 46 no. 6, p. 1694-1701.

Werne, J.P., D.J. Hollander, T.W. Lyons, L.C. Peterson (2000) Climate-induced variations in productivity and planktonic ecosystem structure from the Younger Dryas to Holocene in the Cariaco Basin, Venezuela Paleoceanography, v. 15, no. 1, pp. 19-29.

Werne, J.P., D.J. Hollander, A. Behrens, P. Schaeffer, P. Albrecht, J.S. Sinninghe Damsté (2000) Timing of early diagenetic sulfurization of organic matter: A precursor-product relationship in Holocene sediments of the anoxic Cariaco Basin, Venezuela, Geochimica et Cosmochimica Acta, v. 64, no. 10, pp. 1741-1751.