University of California, Riverside

Alternative Earths Astrobiology Center



Alternative Earths Team Members


Timothy Lyons
Principal Investigator
Center Director

Contact Information

Email: timothy.lyons@ucr.edu
Website: http://earthsciences.ucr.edu/lyons.html


Much of my current work explores the evolving ocean and atmosphere and their cause-and-effect relationships with the origin and evolution of life. Biogeochemical processes that dominate modern and ancient carbonate platforms and oxygen-deficient marine basins are at the heart of this research. Primary methodologies track the signals of microbially mediated cycling of carbon, sulfur, and metals as expressed in their signature isotopic compositions preserved in ancient sedimentary rocks. With my students and colleagues, I am calibrating these proxy methods using modern sediments from the Black Sea, Cariaco Basin in Venezuela, Florida Bay, cold seeps in the Gulf of Mexico, and other settings. We have applied these proxies to deconstruct the paleoenvironmental contexts of Paleozoic black shale deposition and Precambrian biospheric evolution. Particularly exciting are patterns of early atmospheric oxygenation expressed in trace sulfate trapped within carbonate rocks (carbonate-associated sulfate) and in redox-sensitive metals within shales. Related work features marine oxygen isotope records preserved in phosphatic conodonts, iron paleoredox proxies, sulfur geomicrobiology, pathways of metal enrichment, and organic biomarker approaches.

Algeo, T.J. and Lyons, T.W., 2006, Mo–total organic carbon covariation in modern anoxic marine environments: Implications for analysis of paleoredox and paleohydrographic conditions: Paleoceanography, v. 21.

Anbar, A. D., Duan, Y., Lyons, T. W., Arnold, G. L., Kendall, B., Creaser, R. A., Kaufman, A. J., Gordon, G. W., Scott, C., Garvin, J. and Buick, R., 2007, A whiff of oxygen before the Great Oxidation Event?: Science, v. 317, p. 1903-1906.

Asael, D., Tissot, F.L.H., Reinhard, C.T., Rouxel, O., Dauphas, N., Lyons, T.W., Ponzevera, E., Liorzou, C., and Chéron, S., 2013, Coupled molybdenum, iron and uranium stable isotopes as oceanic paleoredox proxies during the Paleoproterozoic Shunga Event: Chemical Geology, v. 362, p. 193-210.

Kaufman, A. J., Johnston, D. T., Farquhar, J., Masterson, A. L., Lyons, T. W., Bates, S., Anbar, A. D., Arnold, G. L., Garvin, J. and Buick, R., 2007, Late Archean biospheric oxygenation and atmospheric evolution: Science, v. 317, p. 1900-1903.

Kelly, A. E., Love, G. D., Lyons, T. W., Bowden, S. A., McGoldrick, P. and Summons, R.E., Reassessing Biomarker Evidence for a Mid-Proterozoic Purple Ocean: Nature Geosciences, submitted. 

Kendall, B., Reinhard, C. T., Lyons, T., Kaufman, A. J., Poulton, S. W. and Anbar, A. D., 2010, Pervasive oxygenation along late Archaean ocean margins: Nature Geoscience, v. 3, p. 647-652.

Konhauser, K. O., Lalonde, S. V., Planavsky, N. J., Pecoits, E., Lyons, T. W., Mojzsis, S. J., Rouxel, O. J., Barley, M. E., Rosiere, C., Fralick, P. W., Kump, L. R. and Bekker, A., 2011, Aerobic bacterial pyrite oxidation and acid rock drainage during the Great Oxidation Event: Nature, v. 478, p. 369.

Lyons, T.W., Anbar, A.D., Severmann, S., Scott, C. and Gill, B., 2009, Tracking euxinia in the ancient ocean: a multiproxy perspective and Proterozoic case study: Annual Review of Earth and Planetary Sciences, v. 37:, p. 507-534.

Lyons, T. W., Reinhard, C. T. and Planavsky, N. J., 2014, The rise of oxygen in Earth's early ocean and atmosphere: Nature, v. 506, p. 307-315.

Lyons, T.W. and Severmann, S., 2006, A critical look at iron paleoredox proxies: New insights from modern euxinic marine basins: Geochimica et Cosmochimica Acta, v. 70, p. 5698-5722.

Ono, S., Whitehill, A.R. and Lyons, J.R., 2013, Contribution of isotopologue self-shielding to sulfur mass-independent fractionation during sulfur dioxide photolysis: Journal of Geophysical Research, v. 118, p. 2444-2454.

Partin, C. A., Bekker, A., Planavsky, N. J., Scott, C. T., Gill, B. C., Li, C., Podkovyrov, V., Maslov, A., Konhauser, K. O., Lalonde, S. V., Love, G. D., Poulton, S. W. and Lyons, T. W., 2013, Large-scale fluctuations in Precambrian atmospheric and oceanic oxygen levels from the record of U in shales: Earth and Planetary Science Letters, v. 369, p. 284-293.

Payne, J.L., McLain, C.R., Boyer, A.G., Brown, J.H., Finnegan, S., Kowalewski, M., Krause Jr., R.A., Lyons, S.K., McShea, D.W., Novack-Gottshall, P.M., Smith, F.A., Spaeth, P., Stempien, J.A. and Wang, S.C., 2011, The evolutionary consequences of oxygenic photosynthesis: a body size perspective: Photosynthesis Research, v. 107, p. 37-57.

Planavsky, N. J., Bekker, A., Hofmann, A., Owens, J. D. and Lyons, T. W., 2012, Sulfur record of rising and falling marine oxygen and sulfate levels during the Lomagundi event: Proceedings of the National Academy of Sciences USA, v. 109, p. 18300-18305.

Planavsky, N. J., McGoldrick, P., Scott, C. T., Li, C., Reinhard, C. T., Kelly, A. E., Chu, X. L., Bekker, A., Love, G. D. and Lyons, T. W., 2011, Widespread iron-rich conditions in the mid-Proterozoic ocean: Nature, v. 477, p. 448-U495.

Raiswell, R., Reinhard, C.T., Derkowski, A., Owens, J., Bottrell, S.H., Anbar, A.D., and Lyons, T.W., 2011, Formation of syngenetic and early diagenetic iron minerals in the late Archean Mt. McRae Shale, Hamersley Basin, Australia: New insights on the patterns, controls and paleoenvironmental implications of authigenic mineral formation: Geochimica et Cosmochimica Acta, v. 75, p. 1072-1087.

Reinhard, C.T., Lalonde, S. and Lyons, T.W., 2013a, Oxidative sulfide dissolution on the early Earth: Chemical Geology, v. 362, p. 44-55.

Reinhard, C.T., Planavsky, N.J. and Lyons, T.W., 2013b, Long-term sedimentary recycling of rare sulphur isotope anomalies: Nature.

Reinhard, C.T., Planavsky, N.J., Robbins, L.J., Partin, C.A., Gill, B.C., Lalonde, S.V., Bekker, A., Konhauser, K.O. and Lyons, T.W., 2013c, Proterozoic ocean redox and biogeochemical stasis: Proceedings of the National Academy of Sciences USA, v. 110, p. 5357-5362.

Reinhard, C. T., Raiswell, R., Scott, C., Anbar, A. D. and Lyons, T. W., 2009, A Late Archean Sulfidic Sea Stimulated by Early Oxidative Weathering of the Continents: Science, v. 326, p. 713-716.

Sahoo, S.K., Planavsky, N.J., Kendall, B., Wang, X.Q., Shi, X.Y., Scott, C., Anbar, A.D., Lyons, T.W. and Jiang, G.Q., 2012, Ocean oxygenation in the wake of the Marinoan glaciation: Nature, v. 489, p. 546-549.

Scott, C., Bekker, A., Reinhard, C.T., Schnetger, B., Krapež, B., Rumble III, D. and Lyons, T.W., 2011, Late Archean euxinic conditions before the rise of atmospheric oxygen: Geology, v. 39, p. 119-122.

Scott, C., Lyons, T. W., Bekker, A., Shen, Y., Poulton, S. W., Chu, X. and Anbar, A. D., 2008, Tracing the stepwise oxygenation of the Proterozoic ocean: Nature, v. 452, p. 456-U455.

Scott, C., Planavsky, N. J., Dupont, C. L., Kendall, B., Gill, B. C., Robbins, L. J., Husband, K. F., Arnold, G. L., Wing, B. A., Poulton, S. W., Bekker, A., Anbar, A. D.,

Konhauser, K. O. and Lyons, T. W., 2013, Bioavailability of zinc in marine systems through time: Nature Geosci, v. 6, p. 125-128.

Scott, C., Wing, B. A., Bekker, A., Planavsky, N. J., Medvedev, P., Bates, S. M., Yun, M. and Lyons, T. W., 2014, Pyrite multiple-sulfur isotope evidence for rapid expansion and contraction of the early Paleoproterozoic seawater sulfate reservoir: Earth and Planetary Science Letters, v. 389, p. 95-104.

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University of California, Riverside
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Riverside, CA 92521
Tel: (951) 827-1012

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Alternative Earths Astrobiology Center
2460 Geology

Tel: (951) 827-3106
E-mail: astrobiology@ucr.edu

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