Dalton Hardisty's work has been focused on placing constraints on how ocean chemistry and early animal life co-evolved with the emergence and proliferation of oxygenic photosynthesis over billion year timescales. Additional work focuses on determining the more recent pre-anthropogenic history of seawater oxygen in coastal settings in order to provide a perspective on natural variable and the impacts and consequences of humans on ocean chemistry. These questions ultimately require studies of the geochemistry of modern seawater and sediments, determining how post-depositional processes (diagenesis) might alter sediment geochemistry, as well as applications toward using the geochemistry of sedimentary rocks to reconstruct how ancient seawater contrasted with that of
Dalton is looking for graduate students starting in the Winter of 2019 or later. Field opportunities for this position will range from expeditions at sea to sampling of Precambrian sediments. Ideal candidates will have a record of independence, some lab experience, and an eager interest in geobiology on any timescale. For more information, contact Dalton at email@example.com. The Graduate Programs page has more information for prospective graduate students.
Lu, W., Ridgewell, A., Thomas, E., Hardisty, D.S., Luo, G., Algeo, T.J., Saltzman, M.R., Gill, B.C., Shen, Y., Ling, H.F., Edwards, C.T., Whalen, M.T., Zhou, X., Gutchess, K.M., Jin, L., Rickaby, R.E.M., Jenkyns, H.C., Lyons, T.W., Lenton, T.M., Kump, L.R., & Lu, Z., 2018, Late inception of a resiliently oxygenated upper ocean. Science 361, 174–177.
Hardisty, D.S., Lyons, T.W., Riedinger, N., Isson, T.T., Owens, J.D., Aller, R.C., Rye, D.M., Planavsky, N.J., Reinhard, C.T., Gill, B.C., Masterson, A.L., & Johnston, D., 2018, An evaluation of sedimentary molybdenum and iron as proxies for pore fluid paleoredox conditions. American Journal of Science 318(5), 527-556.
Raiswell, R., Hardisty, D.S., Lyons, T.W., Canfield, D.E., Owens, J.D., Planavsky, N.J., Poulton, S.W. & Reinhard, C.T., 2018, The iron paleoredox proxies: A guide to the pitfalls, problems and proper practice. American Journal of Science 318(5), 491-526.
Chen, X., Romaniello, S.J., Herrmann, A.D., Hardisty, D.S., Gill, B.C. & Anbar, A.D., 2018, Diagenetic effects on uranium isotope fractionation in carbonate sediments from the Bahamas. Geochimica et Cosmochimica Acta 237, 294-311.
Hardisty, D.S., Lu, Z, Planavsky, N.J., Kah, L.C., Bekker, A., Knoll, A.H., Zhou, X., Osburn, M.R., Loyd, S.J., Jiang, G., Gill, B.C., Diamond, C.W., & Lyons, T.W., 2017, Perspectives on Proterozoic surface ocean redox from iodine contents in ancient and recent carbonate. Earth and Planetary Science Letters 463, 159-170.