John Stix


Processus volcaniques,

Department of Earth and Planetary Sciences

john.stix [at]

Mots clés: volcanologie, pétrologie ignée 

I study active volcano systems. My principal research philosophy is to address important problems in volcanology by applying a multi-disciplinary and integrated approach. This approach has worked very successfully. Some examples of my approach include the role of calderas in certain types of ore deposits, the relationship of degassing to other geophysical parameters of volcano unrest, and the role played by volcanism in terms of human health. During the past five years, my group has tackled the important problem of caldera evolution and caldera structure. We have been employing a combination of field and experimental techniques to elucidate the subsurface structure of calderas. By examining partly eroded calderas in the field as well as surface sections and cross sections of sandbox experiments, we have been able to gain insight into the diversity of structures formed during caldera development. 
The physical processes which occur during degassing and within the conduit system of a volcano are important for eruption style and periodicity, as well as for changing pressure conditions in the magma conduit-reservoir system. I have examined various problems such as the role of diffuse degassing and passive degassing at the surface and within the conduit system itself. These studies typically integrate petrology, textural analysis of rocks, and gas remote sensing.
An important development in my research during the last five years has been the inclusion of experimental approaches and methods to help solve the problems I am studying. Examples include experimental density currents as an analogue for pyroclastic flows, sandbox experiments to model caldera subsidence, and piston-cylinder experiments to investigate boron behavior in vapor-rich and liquid-rich fluids. This experimental approach has been particularly fruitful and gratifying to me, and I expect to greatly expand this aspect over the next five years.

Bray, B., Stix, J., Cousens, B., 2017Mafic replenishment of multiple felsic reservoirs at the Mono domes and Mono Lake islands, CaliforniaBulletin of Volcanology 79 (7), art. no. 54.

Longpré, M.-A., Stix, J., Klügel, A., Shimizu, N., 2017Mantle to surface degassing of carbon- and sulphur-rich alkaline magma at El Hierro, Canary IslandsEarth and Planetary Science Letters 460, 268-280.

Malowany, K.S., Stix, J., de Moor, J.M., Chu, K., Lacrampe-Couloume, G., Sherwood Lollar, B., 2017Carbon isotope systematics of Turrialba volcano, Costa Rica, using a portable cavity ring-down spectrometerGeochemistry, Geophysics, Geosystems 18 (7), 2769-2784.

Seropian, G. and Stix, J., 2017Monitoring and forecasting fault development at actively forming calderas: An experimental studyGeology 46(1), 23-26.

Stix, J., Lucic, G., Malowany, K., 2017. Near real-time field measurements of d13C in CO2 from volcanoesBulletin of Volcanology79 (8), art. no. 62

Coumans, J.P., Stix, J., Clague, D.A., Minarik, W.G., Layne, G.D., 2016Melt-rock interaction near the Moho: Evidence from crystal cargo in lavas from near-ridge seamountsGeochimica et Cosmochimica Acta 191, 139-164.

Kennedy, B., Stix, J., Hon, K., Deering, C., Gelman, S., 2016. Magma storage, differentiation, and interaction at Lake City caldera, Colorado, USAGeological Society of America Bulletin 128, 764-776.

Lucic, G., Berg, A.-S., Stix, J., 2016Water-rich and volatile-undersaturated magmas at Hekla Evolcano, IcelandGeochemistry, Geophysics, Geosystems 17 (8), 3111-3130.

Nadeau, O., Stix, J., Williams-Jones, A.E., 2016Links between arc volcanoes and porphyry-epithermal ore depositsGeology 44 (1) pp. 11-14.

Coumans, J.P., Stix, J., Clague, D.A., Minarik, W.G., 2015The magmatic architecture of taney seamount-A, NE Pacific OceanJournal of Petrology 56 (6), 1037-1067. 

Klügel, A., Longpré, M.-A., García-Cañada, L., Stix, J., 2015Deep intrusions, lateral magma transport and related uplift at ocean island volcanoesEarth and Planetary Science Letters 431, art. no. 13483, 140-149.

Lucic, G., Stix, J., Wing, B., 2015Structural controls on the emission of magmatic carbon dioxide gas, Long Valley Caldera, USAJournal of Geophysical Research B: Solid Earth 120 (4), 2262-2278.

Malowany, K., Stix, J., Van Pelt, A., Lucic, G., 2015H2S interference on CO2 isotopic measurements using a Picarro G1101-i cavity ring-down spectrometerAtmospheric Measurement Techniques 8 (10), 4075-4082

Longpré, M.-.A, Klügel, A., Diehl, A., Stix, J. 2014, Mixing in mantle magma reservoirs prior to and during the 2011-2012 eruption at El Hierro, Canary Islands, Geology, vol. 42, no. 4, pp. 315-318.

Longpré, M.-A., Stix, J., Costa, F., Espinoza, E., Muñoz, A. 2014, Magmatic processes and associated timescales leading to the January 1835 eruption of Cosigüina Volcano, Nicaragua, Journal of Petrology, vol. 55, no. 6, pp. 1173-1201.

Lucic, G., Stix, J., Sherwood Lollar, B., Lacrampe-Couloume, G., Muñoz, A., Carcache, M.I. 2014, The degassing character of a young volcanic center: Cerro Negro, Nicaragua, Bulletin of Volcanology, vol. 76, no. 9, art. 850. 

Helo, C., Clague, D.A., Dingwell, D.B., Stix, J. 2013, High and highly variable cooling rates during pyroclastic eruptions on Axial Seamount, Juan de Fuca Ridge, Journal of Volcanology and Geothermal Research, vol. 253, pp. 54-64. 

Mann, C.P., Wallace, P.J., Stix, J. 2013, Phenocryst-hosted melt inclusions record stalling of magma during ascent in the conduit and upper magma reservoir prior to vulcanian explosions, Soufrière Hills volcano, Montserrat, West Indies, Bulletin of Volcanology, vol. 75, no. 2, pp. 1-16. 

Nadeau, O., Williams-Jones, A.E., Stix, J. 2013, Magmatic-hydrothermal evolution and devolatilization beneath Merapi volcano, Indonesia, Journal of Volcanology and Geothermal Research, vol. 261, pp. 50-68. 

Nadeau, O., Stix, J., Williams-Jones, A.E. 2013, The behavior of Cu, Zn and Pb during magmatic-hydrothermal activity at Merapi volcano, Indonesia, Chemical Geology, vol. 342, pp. 167-179.  

Wilcock, J., Goff, F., Minarik, W.G., Stix, J. 2013, Magmatic recharge during the formation and resurgence of thevalles caldera, new mexico, usa: Evidence from quartz compositional zoning and geothermometry, Journal of Petrology, vol. 54, no. 4, pp. 635-664. 

Girard, G., Stix, J. 2012. Future volcanism at yellowstone caldera: Insights from geochemistry of young volcanic units and monitoring of volcanic unrest. GSA Today, 22(9), 4-10. 

Berlo, K., Stix, J., Roggensack, K., Ghaleb, B., 2012. A tale of two magmas, Fuego, Guatemala, Bulletin of Volcanology, 74 (2), 377-390, doi 10.1007/s00445-011-0530-8.

Stix, J., Phillips, J.C., 2012. An analog investigation of magma fragmentation and degassing: Effects of pressure, volatile content, and decompression rate, Journal of Volcanology and Geothermal Research, 211-212(2), 12-23.

Helo, C., Longpré, M.-A., Shimizu, N., Clague, D.A., Stix, J., 2011. Explosive eruptions at mid-ocean ridges driven by CO 2-rich magmas, Nature Geoscience, 4(4), 260-263.

Girard, G., Stix, J., 2010. Rapid extraction of discrete magma batches from a large differentiating magma chamber: The Central Plateau Member rhyolites, Yellowstone caldera, Wyoming, Contributions to Mineralogy and Petrology, 160(3), 441-465.

Nadeau, O., Williams-Jones, A.E., Stix, J., 2010. Sulphide magma as a source of metals in arc-related magmatic hydrothermal ore fluids, Nature Geoscience, 3(7), 501-506.

Campbell, M.E., Hanson, J.B., Minarik, W.G., Stix, J., 2009. Thermal history of the bandelier magmatic system: Evidence for magmatic injection and recharge at 1.61 Ma as revealed by cathodoluminescence and titanium geothermometry, Journal of Geology, 117 (5), 469-485.

Girard G., J. Stix, 2009. Buoyant replenishment in silicic magma reservoirs: Experimental approach and implications for magma dynamics, crystal mush remobilization, and eruption, J. Geophys. Res., 114, B08203, doi:10.1029/2008JB005791.

Girard, G., Stix, J., 2009.  Magma Recharge and Crystal Mush Rejuvenation Associated with Early Post-collapse Upper Basin Member Rhyolites, Yellowstone Caldera, Wyoming, Journal of Petrology, 50(11), 2095-2125; doi:10.1093/petrology/egp070 .

Mueller, W.U., Stix, J., Corcoran, P.L., Daigneault, R., 2009. Subaqueous calderas in the Archean Abitibi greenstone belt: An overview and new ideas, Ore Geology Reviews, 35 (1), 4-46.

Kennedy, B.M., Mark Jellinek, A., Stix, J., 2008.Coupled caldera subsidence and stirring inferred from analogue models, Nature Geoscience, 1(6), 385-389.

Mueller, W.U., J. Stix, J.D.L. White, P.L. Corcoran, B. Lafrance, and R. Daigneault, 2008. Characterization of Archean subaqueous calderas in Canada: physical volcanology, carbonate-rich hydrothermal alteration and a new exploration model. In. J. Gottsmann and J. Martí (Editors), Caldera Volcanism. Elsevier, Developments in Volcanology, 10: 181-232.

Stix, J., Kobayashi, T., 2008. Magma dynamics and collapse mechanisms during four historic caldera-forming events, Journal of Geophysical Research B: Solid Earth, 113 (9), Article number B09205.

Stix, J., G. Williams-Jones, and C. Hickson, 2008. Applying the COSPEC at active volcanoes. In: Williams-Jones, G., J. Stix, and C.J. Hickson (Editors), The COSPEC cookbook: making SO2 gas measurements at active volcanoes. IAVCEI Methods in Volcanology, 1: 121-168.

Williams-Jones, G., J. Stix, and P.A. Nadeau, 2008. Using the COSPEC in the field. In: Williams-Jones, G., J. Stix, and C.J. Hickson (Editors), The COSPEC cookbook: making SO2 gas measurements at active volcanoes. IAVCEI Methods in Volcanology, 1: 63-120.

Kennedy, B., Stix, J., 2007. Magmatic processes associated with caldera collapse at Ossipee ring dyke, New Hampshire, Bulletin of the Geological Society of America, 119(1-2), 3-17. GEOTOP publication n° 2007-0020

Longpré, M.-A., Staudacher, T., Stix, J., 2007. The November 2002 eruption at Piton de la Fournaise volcano, La Réunion Island: Ground deformation, seismicity, and pit crater collapse, Bulletin of Volcanology, 69(5), 511-525. GEOTOP publication n° 2007-0021

Stix, J., 2007. Stability and instability of quiescently active volcanoes: the case of Masaya, Nicaragua, Geology, 35, 535-538. GEOTOP Publication n° 2007-0019.

Stix, J., 2005. Editorial, Bulletin of Volcanology, 68(1), 1-2. 

Dartevelle, S., Rose, W.I., Stix, J., Kelfoun, K., Vallance, J.W., 2004. Numerical modeling of geophysical granular flows: 2. Computer simulations of plinian clouds and pyroclastic flows and surges, Geochem. Geophys. Geosyst., 5(8), Q08004, DOI 10.1029/2003GC000637.

Kennedy, B., Stix J., Vallance, J.W., Lavallée, Y., Longpré, M.-A., 2004. Controls on caldera structure: results from analogue sandbox modeling, Geol. Soc. Am. Bull., 116, 515-524.

Lavallée, Y., Kennedy, B., Stix, J., Richer, M., Longpré, M.-A., 2004. Caldera subsidence in areas of variable topographic relief: results from analogue modelling, J. Volcanol. Geotherm. Res., 129, 219-236.

Mann, C.P., Stix J., Richer, M., Vallance, J.W., 2004. Subaqueous intracaldera volcanism, Ilopango caldera, El Salvador, Central America, Geol. Soc. Am. Spec. Pap., 375, 159-174.

Mueller, W., J. Stix, J.D.L. White, and G. Hudak, 2004. Archaean calderas. In: P.G. Eriksson, W. Altermann, D.R. Nelson, W.U. Mueller, and O. Catuneanu (Editors), The Precambrian Earth, Tempos and Events. Elsevier, Developments in Precambrian Geology, 12: 345-356.

Richer, M., Mann, C.P., Stix, J., 2004. Mafic magma injection triggering eruption at Ilopango caldera, El Salvador, Central America, Geol. Soc. Am. Spec. Pap., 375, 175-189.

Schatz, O.J., Dolejš, D., Stix, J., Williams-Jones, A.E., Layne, G.D., 2004. Partitioning of boron among melt, brine and vapor in the system haplogranite-H2O-NaCl at 800 °C and 100 MPa, Chemical Geology, 210(1-4), 135-147.

Stix,  J., 2004. Applying the COSPEC at active volcanoes, Geol. Surv. Can. Paper.

Williams-Jones, G., Stix J., 2004. COSPEC field measurements, Geol. Surv. Can. Paper.

Witter, J.B., Kress, V.C., Delmelle, P., Stix, J., 2004. Volatile degassing, petrology, and magma dynamics of the Villarrica lava lake, southern Chile, J. Volcanol. Geotherm. Res., 134, 303-337.

Kennedy, B., Stix, J., 2003Igneous Rock Associations 1: Styles and mechanisms of caldera collapse,Geoscience Canada, 30 (2), 59-72.

Kennedy, B., Stix, J., 2003. Igneous Rock Associations of Canada 2: Stages in the temporal evolution of calderasGeoscience Canada, 30 (3) , 129-140.

Najman, Y., Garzanti, E., Pringle, M., Bickle, M., Stix, J., Khan, I., 2003. Early-middle Miocene paleodrainage and tectonics in the Pakistan Himalaya, Geol. Soc. Am. Bull., 115, 1265-1277.

Lewicki, J.L., Connor, C., St-Amand, K., Stix, J., Spinner, W., 2003. Self-potential, soil CO2 flux, and temperature on Masaya volcano, Nicaragua, Geophys. Res. Lett., 30(15), 1817, DOI 10.1029/2003GL017731.

Stix, J., Kennedy, B., Hannington, M., Gibson, H., Fiske, R., Mueller, W., Franklin, J. 2003. Caldera-forming processes and the origin of submarine volcanogenic massive sulfide deposits, Geology, 31, 375-378.

Stix, J., Layne, G.D., Williams, S.N., 2003. Mechanisms of degassing at Nevado del Ruiz volcano, Colombia, J. Geol. Soc. London, 160, 507-521.

Wardell, L., Delmelle, P., Fischer, T., Lewicki, J., Malavassi, E., Stix, J., Strauch, W., 2003. Volcanic gas workshop features state-of-the-art measurement techniques, EOS, Trans. Am. Geophys. Union, 84(47), 519-520.

Delmelle, P., Stix, J., Baxter, P.J., Garcia-Alvarez, J., Barquero, J., 2002. Atmospheric dispersion, environmental effects and potential health hazard associated with the low-altitude gas plume of Masaya volcano, Nicaragua, Bull. Volcanol., 64, 423-434.

Dartevelle, S., Ernst, G.G.J., Stix, J., Bernard, A., 2002. Origin of the Mount Pinatubo climactic eruption cloud: implications for volcanic hazards and atmospheric impacts, Geology, 30 (7) , 663-666.

Harvey, D.C., Gaonac’h, H., Lovejoy, S., Stix, J., Schertzer, D., 2002. Multifractal characterization of remotely sensed volcanic features: a case study from Kilauea volcano, Hawaii, Fractals, 10, 265-274.

Delmelle, P., Stix, J., Bourque, C. P.-A., Baxter, P.J., Garcia-Alvarez, J., Barquero, J., 2001. Dry deposition and heavy acid loading in the vicinity of Masaya volcano, a major sulfur and chlorine source in Nicaragua, Environ. Sci. & Technol., 35, 1289-1293.

Stix, J., 2001. Flow evolution of experimental gravity currents: implications for pyroclastic flows at volcanoes, J. Geology, 109, 381-398.

Williams-Jones, G., Stix, J., Heiligmann, M., Barquero, J., Fernandez, E., Gonzalez, E.D., 2001. A model of degassing and seismicity at Arenal volcano, Costa Rica, J. Volcanol. Geotherm. Res., 108, 121-139.

Ujike, O., Stix J., 2000. Geochemistry and origins of Ueno and On-take basaltic to andesitic rocks (<3 Ma) produced by distinct contributions of subduction components, central Japan,  J. Volcanol. Geotherm. Res., 95, 49-64. 

Williams-Jones, G., Stix, J., Heiligmann, M., Charland, A., Sherwood Lollar, B., Arner, N., Garzón, V. G., Barquero, J., Fernandez, E.,2000. A model of diffuse degassing at three subduction-related volcanoes, Bull. Volcanol., 62, 130-142.

Watson, I.M., Oppenheimer, C., Voight, B., Francis, P.W., Clarke, A., Stix, J., Miller, A., Pyle, D.M., Burton, M.R., Young, S.R., Norton, G., Loughlin, S., Darroux, B., MVO Staff, 2000. The relationship between degassing and ground deformation at Soufriere Hills volcano, Montserrat, J. Volcanol. Geotherm. Res., 98, 117-126.

Bogue, Robert : Doctorat en sciences de la Terre et des planètes
Sujet de recherche : Trees as passive sensors and archives of volcanic CO2 emissions.
D'Arcy, Fiona : Doctorat en sciences de la Terre et des planètes
Sujet de recherche : CO2 cycling in volcanoes.
Mick, Emily : Doctorat en sciences de la Terre et des planètes
Sujet de recherche : The mechanism of phreatic eruptions.
Oni, Stephen : Maîtrise en sciences de la Terre et des planètes
Sujet de recherche : Fluid. dynamics of magma replenishment.
Salas-Navarro, Jessica : Maîtrise en sciences de la Terre et des planètes
Sujet de recherche : Traçage du méthane dans le système hydrothermal du volcan Rincón de la Vieja, Costa Rica.
Saucier, Émilie : Maîtrise en sciences de la Terre et des planètes
Sujet de recherche : Magma dynamics beneath Viti, Krafla caldera, Iceland
Waelkens, Clara : Doctorat en sciences de la Terre et des planètes
Sujet de recherche : H2O and CO2 in melt inclusions as indicators of magma chamber recharge: Valles Caldera, New Mexico, USA