Ryan Portner


Ryan Portner

Assistant Professor

Phone: 408 924-5009 
Office: DH 202 
Office Hours (Spring 2017): W & R 9:30 AM-10:30 AM or by appointment
E-mail: ryan.portner@sjsu.edu



  • Ph.D. 2010, Macquarie University, Sydney, NSW, AUS

Research Interests

  • I am a sedimentologist with broad interests in volcanology, basin evolution, petrology, tectonics and Earth history. My research integrates field mapping, stratigraphy, petrography, geochemistry, and geochronology to investigate the sedimentary and tectono-magmatic evolution of the Earth. A specific research objective of mine is to better understand eruption dynamics, volcaniclast fragmentation and dispersal processes associated with submarine volcanism. To do this my research team combines field studies of modern and ancient deposits exposed on the seafloor and on land with laboratory based analytical approaches.
  • Introductory Field Camp (GEOL 129A)
  • Petrology (GEOL 122)

Recent Activity (2011-2016)


Peer-reviewed Papers

      • Portner, R.A., Clague D.A., Helo C., Dreyer, B. D., Paduan, (2015). Contrasting styles of deep-marine pyroclastic eruptions revealed from Axial Seamount push core records. Earth and Planetary Science Letters, v. 423, 219-231p. DOI:10.1016/j.epsl.2015.03.043

      • Clague, D.A., Dreyer, B.M., Paduan, J.B., Martin, J.F., Caress, D.W., Gill, J.B., Kelley, D.S., Thomas, H., Portner, R.A.,  Delaney, J.R., Guilderson, T.P., and McGann, M.L. (2014). Eruptive and tectonic history of the Endeavour Segment, Juan de Fuca Ridge, based on AUV mapping data and lava flow ages. Geochemistry Geophysics Geosystems, v. 15, no. 8, pg. 3364-3391. DOI: 10.1002/2014GC005415

      • Portner, R.A., Clague, D.A., Paduan, J.B. (2014). Caldera formation and varied eruption styles on North Pacific seamounts: the clastic lithofacies record. Bulletin of Volcanology, v. 76, no. 845, 28p. DOI: 10.1007/s00445-014-0845-3

      • Clague, D.A., Dreyer, B.M., Paduan, J.B., Chadwick Jr., W.W., Caress, D.W., Embley, R.W., Thomas, H. Portner, R.A., Guilderson, T.P., McGann, M.L., Butterfield, D.A. (2013). Geologic History of the summit of Axial seamount, Juan De Fuca Ridge. Geochemistry Geophysics Geosystems, v. 14, no. 10; p. 4403-4443. DOI: 10.1002/ggge.20240

      • Portner, R.A., Dickinson, J.A., Daczko, N.R. (2011). Interaction of gravity flows with a rugged mid­ocean ridge seafloor: an outcrop example from Macquarie Island. Journal of Sedimentary Research, May 2011, 81 (5) p. 355-375. DOI: 10.2110/jsr.2011.30

      • Portner, R.A., Murphy, M.J., Daczko, N.R, (2011). A detrital record of lower oceanic crust exhumation within a Miocene slow-spreading ridge: Macquarie Island, Southern Ocean. Geological Society of America Bulletin, v. 123, p. 255-273. DOI: 10.1130/B30082.1

      • Portner, R.A., Daczko, N.R., Murphy, M.J., Pearson, N.J. (2011). Enriching mantle melts within a dying mid-ocean spreading ridge: insights from Hf-isotope and trace element patterns in detrital oceanic zircon. Lithos, v. 126, p. 355-368. DOI: 10.1016/j.lithos.2011.07.017

      • Portner, R.A., Hendrix, M.S., Stalker, J.C., Miggins, D.P., Sheriff, S.D. (2011). Sedimentary response to orogenic exhumation in the northern Rocky Mountain Basin and Range province, Flint Creek Basin, west-central Montana. Canadian Journal of Earth Sciences, v. 48, p. 1131-1153. DOI: 10.1139/e10-107

      • Portner, R.A., Daczko, N.R., Dickinson, J.A. (2010). Vitriclastic lithofacies from Macquarie Island (Southern Ocean): compositional influence on abyssal eruption explosivity in a dying Miocene spreading ridge. Bulletin of Volcanology, v. 72, p. 165-183. DOI: 10.1007/s00445-009-0312-8
      • Daczko, N.R., Harb, N., Portner, R.A., Dickinson, J.A. (2009). Geochemical fingerprint of hyaloclasts in glassy fragmental rocks of Macquarie Island. Australian Journal of Earth Sciences, v. 56, p. 951-963.DOI: 10.1080/08120090903005402   
      • Dickinson, J.A., Harb. N., Portner, R.A., Daczko, N.R. (2009). Glassy fragmental rocks of Macquarie Island (Southern Ocean): Mechanism of formation and deposition. Sedimentary Geology, v. 216, p. 91-103. DOI: 10.1016/j.sedgeo.2009.02.001   
      • Portner, R.A Hendrix, M.S. (2005). Preliminary Geologic Mp of the Eastern Flint Creek Basin, West Central Montana. Montana Bureau of Mines and Geology, Open File Report 521, 17 p., 1:24,000.

Recent Awards and Grants

      • 2016 NSF grant #OCE-1634044 - Collaborative Research: Fingerprinting source-to-sink
        associations for d
        eep-marine vitriclastic deposits and their association to caldera formation
        on Axial Seamount
      • 2014 NSF grant # OCE-1355436 - Collaborative research: Dynamics and origins of explosive silicic
        volcanism at 2300 mbsl on a mid-ocean spreading center
      • 2010 MBARI post-doctoral fellowship

Invited Seminars

      • Submarine Volcanism, American Geophysical Union, Hobart, Tasmania, Australian (Janurary 2017)
      • EarthByte group, School of Geosciences, University of Sydney, Sydney Australia (June 2016)
      • Earth Sciences Department, University of New England, Armidale, Australia (June 2016)
      • Earth Sciences Department, University of Tasmania, Hobart, Australia (May 2016)
      • Department of Earth and Ocean Sciences, University of South Carolina, Columbia SC (April 2016)
      • Earth Science department Macquarie University, Sydney Australia (May 2014)
      • Planetary Geology group, Geological Sciences, Brown University, Providence RI (June 2013)
      • Marine Geology and Geophysics group, University of Rhode Island Graduate School of Oceanography, Narragansett Rhode Island (March, 2013)
      • Stanford Project on Deep-Water Depositional Systems (SPODDS), Stanford University School of Earth Sciences, Stanford California (October, 2012)

Reviewing and Editorial Service

      • Portner, R.A., Journal reviewer for:
        • Geochemistry, Geophysics, and Geosystems (G3)
        • Gondwana Research
        • Marine Geology
        • Journal of Volcanology and Geothermal Research
        • Journal of the Geological Society
        • National Science Foundation: Ocean Sciences Program; Petrology Program
        • Foundation for Science and Technology: Portugal