Phone: +1 401 863 1927
Phone 2: +1 401 863 2240
The focus of my research is the experimental, field, and theoretical investigations of the phase equilibria of calc-alkaline magmas. The purpose is to establish mineral stabilities and compositions in these magmas as a function of the fugacities of the volatile species, temperature, and the total pressure. This type of phase equilibrium is used to assess the conditions in pre-eruption subvolcanic magma systems at Mount St. Helens, and in the pre-eruption magma system at Mount Pinatubo, Philippines.
I received a B.Sc. Engineering in 1961 and an M.Sc. in 1963, both at the University of Saskatchewan. I served as a PostDoc, then as an acting Assistant Professor at the University of California/Los Angeles before coming to Brown in 1970. In 1985, I was promoted to Full Professor in the Department of Geological Sciences. Though a Professor Emeritus, I am still very active within the Geochemistry/Mineralogy/Petrology (GMP) research group.
Most of my research has been experimental: field and theoretical investigations of the phase equilibria of calc-alkaline magmas. The purpose of my research is to establish mineral stabilities and compositions in these magmas as a function of the fugacities of the volatile species(H2O, CO2,SO2, Cl etc.), temperature and the total pressure. Originally, this type of phase equilibrium study was used to assess the conditions in pre-eruption subvolcanic magma systems at Mount St. Helens, and more recently, in the pre-eruption magma system at Mount Pinatubo in the Philippines. An investigation of conditions in the andesite composition magmas erupted at Mount Rainier over the past 5000 years was recently completed.
My second major research interest is the rates of volcanic processes. My group has studied the reaction of the hydrous amphibole phenocrysts with the surrounding melt in calc-alkaline magmas as they rise to the surface in attempts to determine the rates of magma ascent in different volcanic systems. The erupted rocks at Mount St. Helens show that this reaction has proceeded to different degrees in different samples, and that most samples contain amphibole populations with different ascent histories. In contrast, the eruption of dacitic magma at Black Butte near Mt. Shasta in northern CA., clearly contains magma which has not experienced any mixing either pre-eruption or during ascent. My latest use of these petrological methods for assessing magma ascent rates is illustrated in the papers on recent eruptions at Montserrat and Unzen. At Montserrat, this method was important in recognizing the changes that were taking place in the rate of magma ascent during the eruption, and in predicting a change from quiet magma effusion to more explosive activity. I am actively involved with collaborators in the U.S. Geological Survey (USGS) studying the new lava dome eruption of Mount St. Helens.
I have been working closely in collaboration with a small group of international scientists to study the parameters that have controlled volcanic eruptions at the Phlegrean fields center near Naples in Italy. This center has been extremely active over the past 35,000 years, with the most recent eruption in 1800 AD.
Studies of magmatic processes on the moon and other terrestrial type planetary bodies continue to be carried out with NASA support. At the same time, the SNC meteorites are being investigated for evidence of magmatic and volcanic conditions on Mars. A part of this project comes from the discovery of andesite composition rocks on the surface of Mars at the Pathfinder site. My team completed a study that demonstrates how these andesite composition magmas could be related by igneous processes to the main group of SNC magmas known to erupt on Mars.
A three-year proposal has been funded by the NASA Mars Data Analysis Program that will allow my group and its associated students to study the nature of magmatic and surface oxidation processes on Mars. Specifically, studies were defined that might explain the compositions of the Mars rocks represented by the SNC meteorites on one hand, and those deduced from spectroscopic study of rock and soil samples at the Mars Pathfinder site on the other. Additionally, I have proposed experiments which might indicate how surface oxidation and alteration of SNC basaltic rocks might alter the spectral properties of the Mars surface, and explain some of the high plagioclase to pyroxene ratios identified in the remotely sensed spectra of the Mars Global Surveyor spacecraft. Finally, this proposal allows Mac's group to continue investigations of volcanism and the role of volatile elements in Martian volcanic processes.
NASA Cosmochemistry Planetary Science Proposal Review Panel 2000; chair in 2001
Member American Geophysical Union Executive Committee for VGP, and chair of the Bowen Award Committee 2002-3
Chair of the Mars Fundamental Analysis Program Peer Review Panel 2004
Member of the University Space Research Foundation Council, 2002-present
Professor Rutherford is a Professor Emeritus, and therefore is no longer teaching.
GEOL 0060: Earthquakes, Volcanic Eruptions & Other Geographic Hazards
GEOL 0230: Geochemistry: Earth & Planetary Materials & their Processes
GEOL 2430: Igneous Petrology
GEOL 2910: Volcanology and Meteorite Petrology
Current PhD Students:
Former Graduate Students:
Leslie Baker, Ph.D. '96
James Brunell, Ph.D. '83
Harry Campbell, Sc.M. '78
Michael Carroll, Ph.D. 86
Brett Conaway, Sc.M. '98
Garland Daniel, Sc.M. '75
Susan Dixon Spulber, Ph.D. '81
Robert Fogel, Ph.D. '89
Danielle Ford, Sc.M. '93
Carl-Henry Geschwind, Sc.M. '90
Renaid Guillemette, Sc.M. '75
Stephen Haase, Sc.M. '75
Peter Hill, Sc.M. '89
Beth Holmberg, Sc.M. '94
Philip Horzempa, Sc.M. '91
Sargon de Jesus, Sc.M. '08
Marie Johnson, Ph.D. '90
Dushon Javonovich, Ph.D. '74
Molly McCanta, PhD '04
Michelle Minitti, PhD '01
Michael Nicholis, PhD '07
Angela Roach, Ph.D. '05
Dudley Schoales, Sc.M. '87
Harold Tuchfeld, Sc.M. '76
Dina Venezky, Ph.D. '98
Robert Wintsch, Ph.D. '75
Three research grants in effect, each for a term of 3 Years; One funded by National Science Foundation (NFS), two from National Aeronautics and Space Administration (NASA).
Also research support from the Istitutio Nazionale di Geofisica e Vulcanologia (INGV) in Italy for collaborative projects on fundamentals of volcanic systems for use in volcanic hazard prediction.