Dr. Debbie Thomas

Bio

Research Interests

• My primary research interest is paleoceanography of the Cretaceous and Paleogene, particularly in using the deep-sea sedimentary record to investigate the relationship between global tectonism and the evolution of the earth's climate system. I use radiogenic isotopes (Nd, Pb, Hf, Sr), stable isotopes, and trace element geochemistry to investigate the effects of changing oceanic basin configurations on the patterns of deep-water formation and thermohaline circulation in order to better understand the potential regulating role of thermohaline circulation on global climate under different boundary conditions. Please see my homepage for specific projects and recent results.

Projects

• Evolution of Atlantic thermohaline circulation patterns from the early Cenozoic "greenhouse" mode to the modern "icehouse" mode
• Investigation of the role of Pacific thermohaline circulation in the climates of the Cretaceous and Paleogene
• Use of radiogenic isotopes (Nd, Pb, Hf) to estimate changes in the flux of ancient deep-water production
• Reconstruction of the onset of deep-water circulation as the South Atlantic basins opened during the Early to Late Cretaceous
• Investigation of the use of Lu-Hf in fish debris as a potential radiometric dating tool
• Eolian sedimentation in the Pacific during the Paleogene

Experience

• Assistant Professor, Texas A&M University, Jan 2004 - present
• Post-doctoral Researcher, University of North Carolina, May 2002 - December 2004

Publications

• Thomas, D.J., Lyle, M., Moore, T.C.,Jr., and Rea, D.K., 2008, Paleogene Deep-water Mass Composition of the Tropical Pacific and Implications for Thermohaline Circulation in a Greenhouse World, Geochem. Geophys. Geosyst., 9, Q02002, doi:10.1029/2007GC001748.
• Thomas, D.J. and Via, R.K., 2007, Neogene Evolution of Atlantic Thermohaline Circulation: Perspective from Walvis Ridge, southeastern Atlantic Ocean, Paleoceanography, 22, PA2212, doi:10.1029/2006PA001297.
• *Via, R.K. and Thomas, D.J., 2006, Evolution of Atlantic Thermohaline Circulation - Timing of the onset of Deep-water Production in the North Atlantic, Geology, 34, 441-444. PDF (also see the Science Highlight)
• Rea, D.K., Lyle, M.W., Liberty, L.M., Hovan, S.A., Bolyn, M.P., Gleason, J.D., Hendy, I.L., Latimer, J.C., Murphy, B.M., Owen, R.M., Paul, C.F., Rea, T.H.C., Stancin, A.M., Thomas, D.J., 2006, Broad region of no sediment in the southwest Pacific basin, Geology, 34, 10, 873-876.
• Thomas, D.J., 2005, Reconstructing ancient deep-sea circulation patterns using the Nd isotopic composition of fossil fish debris, in Isotopic and Elemental Tracers of Late Cenozoic Climate Change , GSA Spec. Pub., v. 395, D. Surge and G. Mora, eds., p. 1-12. PDF
• Thomas, D.J., Bralower, T.J., 2005 , The timing of North Atlantic Igneous Province volcanism relative to the Paleocene/Eocene thermal maximum: Implications for the use of metal concentrations for Large Igneous Province activity. Marine Geology , 217, 233-254. PDF
• Frank, T.D., Thomas, D.J., Leckie, R.M., Arthur, M.A., Bown, P.R., Jones, K., and Lees, J.A., 2005, The Maastrichtian record from a depth transect on Shatsky Rise (northwest Pacific): a tropical perspective on global ecological and oceanographic changes. Paleoceanography, 20, PA1008, 1-14. PDF
• Thomas, D.J., 2004, Evidence for Production of North Pacific Deep Waters During the early Cenozoic Greenhouse. Nature, 430, 65-68. PDF (also see the News & Views about the paper)
• Thomas, D.J., Bralower, T.J., and Jones, C.E., 2003, Neodymium Isotopic Reconstruction of Late Paleocene - Early Eocene Thermohaline Circulation. Earth Planet. Sci. Lett ., 209, 309-322. PDF
• Thomas, D.J. , Zachos, J.C., Bralower, T.J., Thomas, E., and Bohaty, S., 2002, Warming the Fuel for the Fire: Evidence for the thermal dissociation of methane hydrate during the Paleocene-Eocene thermal maximum. Geology , 30: 1067-1070. PDF
• Thomas, D.J., Bralower, T.J., and Zachos, J.C., 1999, New evidence for subtropical warming during the late Paleocene thermal maximum: Stable isotopes from Deep Sea Drilling Project Site 527, Walvis Ridge. Paleoceanography , 14: 561-570. PDF
• Bralower, T.J., Thomas, D.J., Thomas, E., and Zachos, J.C., 1998. Reply. Geology , 26: 671.
• Bralower, T.J., Thomas, D.J., Zachos, J.C., Hirschmann, M.M., Rohl, U., Sigurdsson, H., Thomas E., and Whitney, D.L., 1997, High-resolution records of late Paleocene thermal maximum and circum-Caribbean volcanism: Is there a causal link? Geology , 25: 963-966. PDF
• Herbert, T.D., Schuffert, J.D., Thomas, D., Lange, C., Weinheimer, A., Peleo-Alampay, A., and Herguera, J.-C., 1999, A core-top calibration of alkenone unsaturation in California Margin sediments. Paleoceanography, 13: 263-271.
  
  *indicates student primary authorship

Links

• My Research Page