Peer-Reviewed Publications(1Graduate Student Advisee; 2Post-Doctoral Advisee)


    1. Wang, X.1, Planavsky, N.J., Hofmann, A., Saupe, E.E., De Corte, B.P., Philippot, P., LaLonde, S.V., Jemison, N.E., Zou, H., Ossa Ossa, F., Rybacki, K., Alfimova, N., Larson, M.J., Tsikos, H., Fralick, P.W., Johnson, T.M., Knudsen, A.C., Reinhard, C.T., Konhauser, K.O., 2018. A Mesoarchean Shift in Uranium Isotope Systematics. Geochimica et Cosmochimica Acta, 238, 438-452. DOI: 10.1016/j.gca.2018.07.024
    2. Jemison, N.E. 1, Shiel, A.E. 2, Johnson, T.M., Lundstrom, C.C., Long, P.E., Williams, K.H., 2018. Field Application of 238U/235U Measurements To Detect Reoxidation and Mobilization of U(IV). Environ. Sci. Technol. 52, 3422-3430. DOI: 10.1021/acs.est.7b05162


    3. Jemison, N.E1., Johnson, T.M., Shiel, A.E2., Lundstrom, C.C., 2016. Uranium Isotopic Fractionation Induced by U(VI) Adsorption onto Common Aquifer Minerals. Environ. Sci. Technol. 50, 12232-12240. DOI: 10.1021/acs.est.6b03488
    4. Basu, A., Schilling, K.2, Brown, S.T., Johnson, T.M., Christensen, J.N., Hartmann, M., Reimus, P.W., Heikoop, J.M., WoldeGabriel, G., DePaolo, D.J., 2016. Se Isotopes as groundwater redox indicators: Detecting natural attenuation of Se at an in situ recovery U mine. Environmental Science & Technology.  DOI: 10.1021/acs.est.6b01464
    5. Mitchell, K.1, Mansoor, S. Z., Mason, P.R.D., Johnson, T.M., Van Cappellen, P., 2016. Geological evolution of the marine selenium cycle: Insights from the bulk shale δ82/76Se record and isotope mass balance modeling. Earth Planet. Sci. Lett. 441, 178-187. DOI: 10.1016/j.epsl.2016.02.030
    6. Wang, X.-l. 1, Reinhard, C.T., Planavsky, N.J., Owens, J.D., Lyons, T.W., Johnson, T., 2016. Sedimentary chromium isotopic compositions across the Cretaceous OAE2 at Demerara Rise Site 1258. Chem. Geol., 429, 85–92.
    7. Wang, X.-l. 1, Planavsky, N.J., Reinhard, C.T., Hein, J.R., Johnson, T.M., 2016, A Cenozoic Seawater Redox Record Derived from 238U/235U in Ferromanganese Crusts. Amer. J. Sci., 316, 64-83. DOI: 10.2475/01.2016.02
    8. Shiel, A.E.2, Johnson, T.M., Lundstrom, C.C., Laubach, P.G., Long, P.E., Williams, K.H., 2016. Reactive transport of uranium in a groundwater bioreduction study: Insights from high-temporal resolution 238U/235U data. Geochim. Cosmochim. Acta, 187, 218-236.  DOI:10.1016/j.gca.2016.05.020


    9. Wang, X. 1, Johnson, T.M., Ellis, A.S., 2015. Equilibrium isotopic fractionation and isotopic exchange kinetics between Cr(III) and Cr(VI). Geochim. Cosmichim. Acta 153, 72-90.  DOI: 10.1016/j.gca.2015.01.003
    10. Wang, X. 1, Johnson, T.M., Lundstrom, C.C., 2015. Low temperature equilibrium isotope fractionation and isotope exchange kinetics between U(IV) and U(VI). Geochim. Cosmichim. Acta 158, 262-275.  DOI: 10.1016/j.gca.2015.03.006
    11. Wang, X. 1, Johnson, T.M., Lundstom, C.C., 2015. Isotope fractionation during oxidation of tetravalent uranium by dissolved oxygen. Geochim. Cosmichim. Acta, 150, 160-170.  DOI: 10.1016/j.gca.2014.12.007
    12. Schilling, K. 2, Johnson, T.M., Dhillon, K.S., Mason, P.R.D., 2015. Fate of selenium in soils at a seleniferous site recorded by high precision Se isotope measurements. Env. Sci. Technol. 49, 9690–9698. DOI: 10.1021/acs.est.5b00477


    13. Zhu, J.-M., Johnson, T.M., Clark, S.K. 1, Zhu, X.-K., Wang, X.-L. 1, 2014. Selenium redox cycling during weathering of Se-rich shales: A selenium isotope study. Geochim. Cosmichim. Acta 126, 228-249. DOI:  10.1016/j.gca.2013.11.004
    14. Xie, X., Johnson, T.M., Wang, Y., Lundstrom, C.C., Ellis, A., Wang, X. 1, Duan, M., Li, J., 2014. Pathways of arsenic from sediments to groundwater in the hyporheic zone: Evidence from an iron isotope study. Journal of Hydrology 511, 509-517. DOI: 10.1016/j.jhydrol.2014.02.006
    15. Wang, Y.X., Xie, X.J., Johnson, T.M., Lundstrom, C.C., Ellis, A., Wang, X.L., Duan, M.Y., Li, J.X., 2014. Coupled iron, sulfur and carbon isotope evidences for arsenic enrichment in groundwater. Journal of Hydrology 519, 414-422.
    16. Basu, A. 1, Sanford, R.A., Johnson, T.M., Lundstrom, C.C., Löffler, F.E., 2014, Uranium Isotopic Fractionation Factors during U(VI) Reduction by Bacterial Isolates. Geochim. Cosmochim. Acta 136, 100-113.  DOI: 10.1016/j.gca.2014.02.041
    17. Planavsky, N.J., Asael, D., Hofmann, A., Reinhard, C.T., Lalonde, S.V., Knudsen, A., Wang, X., Ossa Ossa, F., Pecoits, E., Smith, A.J.B., Beukes, N.J., Bekker, A., Johnson, T.M., Konhauser, K.O., Lyons, T.W., Rouxel, O.J., 2014. Evidence for Oxygenic Photosynthesis Half a Billion Years Before the Great Oxidation Event. Nature Geosci. 7, 283-286 doi:10.1038/ngeo2122.
    18. Heikoop, J.M., Johnson, T.M., Birdsell, K.H. Longmire, P., Hickmott, D.D., Jacobs, E.P., Broxton, D.E., Katzman, D., Vesselinova, V.V.,  Dinga, M., Vaniman, D.T., Reneaua, S.L., Goering, T.J., Glessner, J., and Basu, A. 1 Isotopic evidence for reduction of anthropogenic hexavalent chromium in Los Alamos National Laboratory groundwater., Chem. Geol. 373, 1–910.  DOI: 1016/j.chemgeo.2014.02.022
    19. Schilling, K. 2, Johnson, T.M., Mason, P.R.D., A sequential extraction technique for mass-balanced stable selenium isotope analysis of soil samples. Chemical Geology, 381, 125-130.  DOI:10.1016/j.chemgeo.2014.04.014
    20. Reinhard, C.T., Planavsky, N.J., Wang, X., Fischer, W.W., Johnson, T.M., Lyons, T.W., 2014. The isotopic composition of authigenic chromium in anoxic marine sediments: A case study from the Cariaco Basin. Earth and Planetary Science Letters 407, 9-18.
    21. Planavsky, N.J., Reinhard, C.T., Wang, X., Thomson, D., McGoldrick, P., Rainbird, R.H., Johnson, T., Fischer, W.W., Lyons, T.W., 2014. Low Mid-Proterozoic atmospheric oxygen levels and the delayed rise of animals. Science 346, 635-638.  DOI: 10.1126/science.1258410
    22. Basu, A. 1, Johnson, T.M., Sanford, R.A., 2014. Cr isotope fractionation factors for Cr(VI) reduction by a metabolically diverse group of bacteria. Geochimica et Cosmochimica Acta 142, 349-361.


    23. Mitchell, K. 1, Couture, R.-M., Johnson, T.M., Mason, P.R.D., Van Cappellen, P., 2013. Selenium sorption and isotope fractionation: Iron(III) oxides versus iron(II) sulfides. Chemical Geology 342, 21-28. DOI:  10.1016/j.chemgeo.2013.01.017
    24. Xie, X., Johnson, T.M., Wang, Y., Lundstrom, C.C., Ellis, A., Wang, X., Duan, M., 2013. Mobilization of arsenic in aquifers from the Datong Basin, China: Evidence from geochemical and iron isotopic data. Chemosphere 90, 1878-1884.
    25. Shiel, A.E. 2, Laubach, P.G. 1, Johnson, T.M., Lundstrom, C.C., Long, P.E., Williams, K.H., 2013. No Measurable Changes in 238U/235U due to Desorption-Adsorption of U(VI) from Groundwater at the Rifle, Colorado, Integrated Field Research Challenge Site. Environmental Science & Technology 47, 2535-2541.
    26. Mead, C. 1, Lyons, J.R., Johnson, T.M., Anbar, A.D., 2013. Unique Hg Stable Isotope Signatures of Compact Fluorescent Lamp-Sourced Hg. Environmental Science & Technology 47, 2542-2547.
    27. Schilling, K. 1, Johnson, T.M., Wilcke, W., 2013. Isotope fractionation of selenium by biomethylation in microcosm incubations of soil. Chemical Geology 352, 101-107. DOI: 10.1016/j.chemgeo.2013.05.013


    28. Johnson, T.M., 2012. Stable Isotopes of Cr and Se as Tracers of Redox Processes in Earth Surface Environments, in: Baskaran, M. (Ed.), Handbook of Environmental Isotope Geochemistry. Springer, New York, pp. 155-176.
    29. Mitchell, K. 1, Mason, P.R.D., Van Cappellen, P., Johnson, T.M., Gill, B.C., Owens, J.D., Diaz, J., Ingall, E.D., Reichart, G.-J., Lyons, T.W., 2012. Selenium as paleo-oceanographic proxy: A first assessment. Geochim. Cosmochim. Acta 89, 302-317.
    30. Kitchen, J.W. 1, Johnson, T.M., Bullen, T.D., Zhu, J., Raddatz, A.L., 2012. Chromium isotope fractionation factors for reduction of Cr(VI) by aqueous Fe(II) and organic molecules. Geochim. Cosmichim. Acta 89, 190-201.
    31. Basu, A. 1, Johnson, T.M., 2012. Determination of Hexavalent Chromium Reduction Using Cr Stable Isotopes: Isotopic Fractionation Factors for Permeable Reactive Barrier Materials. Environmental Science & Technology 46, 5353-5360.
    32. Villalobos-Aragón, A., Ellis, AS, Armienta, MA, Morton-Bermea, O., Johnson, TM, 2012. Geochemistry and Cr Stable Isotopes of Cr-Contaminated Groundwater in León valley, Guanajuato, México, Applied Geochemistry 27, 1783-1794.
    33. Zhu, J.-M., Johnson, T.M., Finkelman, R.B., Zheng, B.-S., Sykorova, I., Pesek, J., 2012. The occurrence and origin of selenium minerals in Se-rich stone coals, spoils and their adjacent soils in Yutangba, China. Chemical Geology 330-331, 27-38.
    34. Bartov, G. 1, Deonarine, A., Johnson, T.M., Ruhl, L., Vengosh, A., Hsu-Kim, H., 2012. Environmental Impacts of the Tennessee Valley Authority Kingston Coal Ash Spill. 1. Source Apportionment Using Mercury Stable Isotopes. Environmental Science & Technology 47, 2092-2099.
    35. Deonarine, A., Bartov, G. 1, Johnson, T.M., Ruhl, L., Vengosh, A., Hsu-Kim, H., 2012. Environmental Impacts of the Tennessee Valley Authority Kingston Coal Ash Spill. 2. Effect of Coal Ash on Methylmercury in Historically Contaminated River Sediments. Environmental Science & Technology 47, 2100-2108.


    36. Schilling, K., Johnson, T.M. and Wilcke, W., 2011. Selenium partitioning and stable isotope ratios in urban topsoils. Soil Science Society of America Journal, 75, 1354-1364.
    37. Schilling, K., Johnson, T.M. and Wilcke, W., 2011. Isotope Fractionation of Selenium During Fungal Biomethylation by Alternaria alternata. Environmental Science & Technology, 45(7): 2670-2676.


    38. Berna, E.C. 1, Johnson, T.M., Makdisi, R.S. and Basui, A. (2010). Cr Stable Isotopes As Indicators of Cr(VI) Reduction in Groundwater: A Detailed Time-Series Study of a Point-Source Plume. Environmental Science & Technology, 44(3): 1043-1048.  DOI:10.1021/Es902280s
    39. Mead, C. 1 and Johnson, T.M. (2010) Hg stable isotope analysis by the double-spike method. Anal. Bioanal. Chem., 397:1529–1538. DOI: 10.1007/s00216-010-3701-0
    40. Clark, S.K. 1 and Johnson, T.M. (2010) Selenium Stable Isotope Investigation into Selenium Biogeochemical Cycling in a Lacustrine Environment: Sweitzer Lake, Colorado. Journal of Environmental Quality, 39(6): 2200-2210.
    41. Bopp, CJ (IV), Lundstrom, CC, Johnson, TM, Sanford, R, Long, P. and Williams, K. (2010) Uranium Isotope Ratios as Indicators of Reduction: Results from an in situ Biostimulation Experiment at Rifle, CO, Environ. Sci. Technol., 44 (15), pp 5927–5933.
    42. Widory, D., Petelet-Giraud, E., Le Bihan, O., Le Moullec, Y. Quetel, C., Snell, J., Van Bocxstaele, M., Hure, A., Canard, E., Joos, E., Fori, L., Bullen, T., Johnson, T., and Fiani, E.  (2010) Les métaux dans les particules atmosphériques : les isotopes peuvent-ils aider à discriminer les pôles d’émission potentiels ? Metals in atmospheric particles: can isotopes help discriminate potential sources?  Pollution Atmospherique, September, 2010.
    43. Raddatz AL1, Johnson TM, McLing TL (2010) Cr Stable Isotopes in Snake River Plain Aquifer Groundwater: Evidence for Natural Reduction of Dissolved Cr(VI). Environmental Science & Technology 45:502-507.

      2009 and earlier

    44. Charles John Bopp, Craig C. Lundstrom, Thomas M. Johnson, and Justin J. G. Glessner , (2009). Variations in 238 U/ 235 U in uranium ore deposits; isotopic signatures of the U reduction process?  Geology  37(7):611-614. DOI: 10.1130/G25550A.1
    45. Bethke, C.M. and Johnson, T.M., 2008. Groundwater Age and Groundwater Age Dating. Ann. Rev. Earth Planet. Sci., 36: 121-152.
    46. Clark, S.K1. and Johnson, T.M., 2008. Effective isotopic fractionation factors for solute removal by reactive sediments: A laboratory microcosm and slurry study. Environ. Sci. Technol., 42(21): 7850-7855.
    47. Hedman, K.M., Curry, B.B., Johnson, T.M., Fullagar, P.D. and Emerson, T.E., 2008. Variation in strontium isotope ratios of archaeological fauna in theMidwestern United States: A preliminary study J. Archaeolog. Sci., 36: 64-73.
    48. Sikora, E.R. 1, Johnson, T.M. and Bullen, T.D., 2008. Microbial mass-dependent fractionation of chromium isotopes. Geochim. Cosmochim. Acta, 72: 3631–3641.
    49. Mehnert E., Hwang H.-H., Johnson T. M., Sanford R. A., Beaumont W. C. 1, and Holm T. R. (2007) Denitrification in the shallow ground water of a tile-drained, agricultural watershed. J. Environ. Qual. 36, 80-90.
    50. Rademacher, L. K., Lundstrom, C. C., Johnson, T.M., Sanford, R. A., Zhao, J., and Zhang, Z.  (2006) Experimentally Determined Uranium Isotope Fractionation During Reduction of Hexavalent U by Bacteria and Zero Valent Iron.  Env. Sci. Technol., 40, 6943-6948.
    51. Johnson, T.M. (2004) A review of mass-dependent fractionation of selenium isotopes and implications for other heavy stable isotopes. Chemical Geology, 204, 201-214.
    52. Johnson, T.M. and Bullen, T.D. (2004). Mass-dependent fractionation of selenium and chromium isotopes in low-temperature environments. In: C.M. Johnson, B.L. Beard and F. Albarede (Editors), Geochemistry of Non-Traditional Stable Isotopes. Rev. Mineral. 55, Mineral. Soc. Amer., Washington, D.C., 289-317.
    53. Johnson, T. M. and Bullen, T. D. (2004) Selenium, Iron and Chromium Stable Isotope Ratio Measurements by the Double Isotope Spike TIMS Method, in , P. DeGroot, ed., Handbook of Stable Isotope Analytical Techniques, Ch. 29, pp. 632-651, Elsevier, Amsterdam.
    54. Ellis A. S1., Johnson T. M., and Bullen T. D. (2004) Using Chromium Stable Isotope Ratios to Quantify Cr(VI) reduction: Lack of Sorption Effects. Env. Sci. Technol.38, 3604-3607.
    55. Johnson T. M. and Bullen T. D. (2003) Selenium isotope fractionation during reduction of Se oxyanions by Fe(II) + Fe(III) hydroxide-sulfate (green rust), Geochimica et Cosmochimica Acta, 67, 413-419.
    56. Ellis A. S1., Johnson T. M., Bullen T. D., and Herbel M. J2. (2003) Stable isotope fractionation of selenium by natural microbial consortia. Chem. Geol., 195, 119-129.
    57. Bethke, C. M., and Johnson T. M., (2002) Paradox of groundwater age, Geology, 30, 385-388.
    58. Herbel, M.J2., Johnson, T.M., Tanji, K. K., Gao, S., and Bullen, T.D. (2002) Selenium stable isotope ratios in California agricultural drainage water, Journal of Environmental Quality 31(4), 1146-1156.
    59. Bethke, C.M., and Johnson, T.M., (2002) Ground water age.  Ground Water40, 337-339.
    60. Ellis A. S1., Johnson T. M., and Bullen T. D., (2002) Cr isotopes and the fate of hexavalent Cr in the environment. Science, 265, 2060-2062.
    61. Park, J., Bethke, C. M., Torgersen, T., and Johnson, T.M. (2002) Transport modeling applied to the interpretation of 36Cl age. Water Resources Research, 38 (5) DOI 10.1029/2001WR000399.
    62. McLing, T. L., Smith, R. W., and Johnson, T.M., (2002) Chemical characteristics of thermal water beneath the eastern Snake River Plain aquifer, in L.L. Mink and P. K. Link, eds., Geology, hydrogeology, and environmental remediation: Idaho National Engineering and Environmental Laboratory, Eastern Snake River Plain,   Idaho, Geological Society of America Special Paper 353, 205-212.
    63. Roback R. C., Johnson T. M., McLing T. L., Murrell M. T., Luo, S. and Ku, T.-L. (2001) Uranium isotopic evidence for groundwater chemical evolution and flow patterns in the eastern Snake River Plain aquifer, Idaho, Geological Society of America Bulletin, 113, 1133-1141.
    64. Johnson T. M., Roback R. C., McLing T. L., Bullen T. D., DePaolo D. J., Doughty C., Hunt R. J., Murrell M. T., and Smith R. W. (2000) Groundwater ‘Fast Paths’ in the Snake River Plain Aquifer: Radiogenic Isotope Ratios as Natural Groundwater Tracers, Geology, 28, 871-874.
    65. Herbel, M.J2., Johnson, T.M., Oremland, R.S., Bullen, T.D. (2000) Fractionation of Selenium Isotopes during Bacterial Respiratory Reduction of Selenium Oxyanions, Geochimica et Cosmochimica Acta, 64, 3701-3709.
    66. Johnson, T. M., Bullen, T. D., and P. T. Zawislanski (2000) Selenium stable isotope ratios as indicators of sources and cycling of selenium: Results from the northern reach of San Francisco Bay, Environmental Science and Technology,34, 2075-2079.
    67. Johnson, T.M., Herbel, M.J2., Bullen, T.D., and Zawislanski, P.T. (1999) Se isotope ratios as indicators of Se sources and oxyanion reduction, Geochimica et Cosmochimica Acta, 63, 2775-2784.
    68. Johnson, T.M. and DePaolo, D.J., (1997) Rapid exchange effects on isotope ratios in groundwater systems, 2,  Flow investigation using Sr isotope ratios. Water Resources Research, 33, 197-210.
    69. Johnson, T.M. and DePaolo, D.J., (1997) Rapid exchange effects on isotope ratios in groundwater systems, 1,  Development of a transport-dissolution-exchange model. Water Resources Research, 33, 187-196.
    70. Johnson, T.M. and DePaolo, D.J., (1996) Reaction-transport models for radiocarbon in groundwater:  The effects of dispersive transport and the use of Sr isotope ratios to correct for water-rock interaction. Water Resources Research, 32, 2203-2212.
    71. Johnson, T.M. and DePaolo, D.J., (1994) Interpretation of isotopic data in groundwater systems:  Model development and application to Sr isotope data from Yucca Mountain.  Water Resources Research, 30, 1571-1587.