Citation for Mark Ghiorso

Mark Ghiorso

Ms. President, thank you. First of all, Mark, thanks for inviting me to be part of this night when we celebrate your career and the use of quantitative thermodynamic models to understand magmatic processes. It is a great pleasure to be here.

Mark is part of a generation of petrologists who worked with Ian Carmichael at Berkeley. From that amazing nursery of talent, Mark emerged as the leading force in the development of thermodynamic models of magmas and coexisting minerals. Mark proceeded to develop a comprehensive description of the phase relations between minerals and melt in magmas, an effort that took some 15 years to yield its first version. That Mark pursued this is a testament to his vision and perseverance. Albeit imperfect, MELTS allows us to rigorously model the evolution of magmas and the associated mineral and volatile assemblages. The 1995 paper alone has drawn more than 1500 citations, and altogether, Mark’s work has drawn more than 6000 citations. These are not empty metrics; they are a clear demonstration that MELTS has become part of the modus operandi of petrology and geochemistry and of the tremendous influence of his work.

But Mark is much bigger than MELTS. Mark is an incredible teacher, as you could see this morning in full display. Mark is a fabulous mentor. I cannot overstate his influence in my own career. His students include two former Bowen awardees and a Macelwane awardee, one of whom is about to also receive the Mineralogical Society of America’s Dana Medal. Such a track record of mentorship is worthy of an award by itself.

Mark has always had the clarity and vision to understand that computational thermodynamics is just a tool to address important scientific questions. From partial melting in the mid-ocean ridges, to the phase relations in the deep mantle, to the evolution of silicic magmas in the shallowest crust, Mark has been involved in work that has greatly influenced our thinking.

It could not be more fitting for Mark to receive the Bowen Award. First, Mark’s work builds directly on the legacy of experimental petrology mastered by Bowen. Secondly, Mark has been a fundamental contributor to the effort of putting such experimental work onto solid theoretical footing. Finally, Mark has managed to create the tools that allow every petrologist to perform calculations that are unfathomable to most of us. And he has done so while addressing fundamental problems in petrology and geochemistry.

I wish Mark had dedicated some of his time to the cloning business because we could use a few more copies of him. But he is not looking back at his career; he’s looking forward, creating unbelievably clever and powerful methods to address petrologic problems, as he says, at the speed of thought. We have been incredibly fortunate to have Mark devote his time and energy to petrology and geochemistry, and we can be assured of many more productive years in his career.

Members of the Volcanology, Geochemistry, and Petrology (VGP) section, it fills me with tremendous joy to call all of you to join me in congratulating Master Ghiorso as he receives a 2014 Norman L. Bowen Award.

—Guilherme A. R. Gualda, Vanderbilt University, Nashville, Tenn.


It is both exhilarating and humbling to be awarded an honor named after Norman L. Bowen. I can’t help but ask, “What would Bowen think about this choice?” Would he be appalled, indifferent, or intrigued? I hope that his response would be the last.

I was both an undergraduate and graduate student at the University of California, Berkeley, during the 1970s. I went to Berkeley because it was the local school, because tuition was essentially free, and because I was fascinated as a high school student with hot springs, volcanos, and, in particular, the work of Howell Williams and Arthur L. Day. Day was no longer living, but Williams was still alive and at Berkeley. I got to Berkeley and began to take courses from Garnis Curtiss and Charles Gilbert and this young guy with a funny cockney accent named Ian Carmichael. Then, as a junior I took a class from Hal Helgeson. That changed my life because I discovered in Hal the style of scientific pursuit that I wanted to spend the rest of my life doing. I stayed at Berkeley for graduate school, deciding to work with Ian. It has always been important to me to work with people who have a sense of humor. Carmichael had a brilliant mind, an uncanny ability to motivate and mentor students, but most of all he had a great sense of humor.

At Berkeley my fellow graduate students included Charlie Bacon, Wes Hildreth, Frank Spera, Gail Mahood, Jim Luhr, Jon Stebbins, and Mark Rivers. I thought it was normal to be surrounded by intellect of this caliber, and I did not realize how lucky I was. I took courses from Leo Brewer, Ken Pitzer, and Jon Prausnitz, and I was able to hover about Helgeson as he completed his seminal synthesis of the thermodynamic properties of aqueous solutions and the rock-forming minerals.

Ian Carmichael ignited my interest in the thermodynamics of silicate melts, and he shared with and encouraged the work which has occupied me since that time. Ian introduced me to Richard Sack, from whom I learned all about the thermodynamics of solid solutions. That was another extraordinary stroke of luck, as was working with Ed Stolper, whose generosity of spirit stands out as a high point in my career.

I want to thank the faculty at the University of Washington, where I worked for 23 years, especially my first two chairs, John Adams and Tom Dunne, for encouraging me to do what I do even if I could not get it funded. In addition, I thank my extraordinary students Peter Kelemen and Marc Hirschmann for their gifted insights and my consummate experimental colleague Victor Kress. I have since 2005 had the great fortune of working with Guil Gualda, who introduced me this evening. That collaboration has been so much fun that I hope it never ends. I want to thank him for nudging me to work on silicic magmas that I never thought would be so fascinating.

It is a wonderful thing to receive the Bowen Award, and I sincerely thank the committee and the VGP membership for selecting me for this magnificent honor.

—Mark Ghiorso, OFM Research, Redman, Wash.

Citation for Richard O. Sack

Richard O. Sack

I am very pleased and honored to introduce Richard Sack, the corecipient of this year’s Norman L. Bowen Award of the American Geophysical Union (AGU). This award is given annually to individuals who have made outstanding contributions to volcanology, geochemistry, or petrology. Richard Sack is certainly one of those unique scientists.

His work on the thermochemistry of sulfides proved that experiment and theory have relevance to studying ore deposits. After a decade of sulfide work, Richard returned to solid solutions found in meteorites, most recently, to those relevant to the petrogenesis of calcium-aluminum inclusions in carbonaceous chondrites, defect spinels, and now fassaites. In addition, Richard Sack’s and Mark Ghiorso’s publications on thermodynamics of multicomponent pyroxenes have provided new understanding of the phase relations of these complicated but extremely important mineral systems.

Richard has been an affiliate faculty member of the Department of Earth and Space Sciences of the University of Washington since 1993, and he founded the not-for-profit OFM Research Corporation with Mark Ghiorso in 2005. Richard provided experimental data and constructed solution models for minerals to calibrate the SILCAL model, predecessor of MELTS. Mark and Richard collaborated to produce thermodynamically viable models for minerals, which led to the calibration of the original MELTS software. Mark Ghiorso and his coworkers afterward produced many variants and improvements in models for silicate melts in the code. This is truly a significant scientific contribution to a quantitative understanding of mineral-melt systems. More than a quarter of a million visits in 2014 alone show the global interest in this software. Norman Bowen would doubtless have loved to check his experimental results against the output of the MELTS.

It is my great pleasure and honor to present to you my friend and colleague, the 2014 Norman Bowen Award corecipient, Dr. Richard Sack.

—Attila Kilinc, University of Cincinnati, Cincinnati, Ohio


Thank you, Attila! I am pleased to accept this Norman Bowen Award on behalf of all the individuals who helped me achieve this recognition. My parents, Bernhard and Mary, and brother, John, are high on this list, as are Ron Brown and Leo Matthew Hall, who introduced me to chemistry and mineralogy, and Philip R. Whitney, who introduced me to coronas in Adirondack mafic granulites and persuaded me to continue my studies in metamorphic petrology with James B. Thompson Jr. During these studies I met many interesting characters, including Tim Grove, Mike Mottl, Barbara Luedtke, Nicolas DarBois, Steve Bushnell, Ed Stolper, and Dave Walker. I am forever in the debt of Dave, Ian Carmichael, and Jim Thompson for arranging for the postdoc that enabled me to meet Hal Helgeson, Peter Lichtner, and the MELTS architect, my colleague at OFM Research and long-term collaborator, Mark Ghiorso.

I also thank Attila Kilinc, Atilla Aydin, Cliff Kubiak, Dave Gaskell, Arvid Johnson, Tom Tharp, Mark Ghiorso, Marc Hirschmann, Bruce Nelson, Nick Hayman, John Fitzpatrick, and Bill and Betty Clinkenbeard, Scott Kuehner, Carl Hager, Dave McDougall, Ed Mulligan, Jamie Allan, and Victor Kress for their sage advice, friendship, assistance, and collaboration. I am grateful to Phil Goodell and Lisa Hardy for introducing me to practical mining geology, Peter Lichtner for helping me keep my signs straight, and my former graduate students Ken Raabe, Roy Hill, Mike O’Leary, Lauren Gee Carroll, William Azeredo, Denton Ebel, Daniel Harlov, Shuvo Ghosal, Irfan Yolcubal, Alexey Balabin, and Nathan Chutas for doing the hard work that makes all this possible. I thank my family, Odee, Filo, Milo, and O’Win, and their predecessors Olde, Fidelity, and Morgan, for always racing to my side. And, finally, I want to thank the Volcanology, Geochemistry, and Petrology section of the AGU for this honor.

—Richard O. Sack, OFM Research, Redmond, Wash.

Citation: AGU (2015), Ghiorso and Sack receive 2014 Norman L. Bowen Award, Eos, 96, doi:10.1029/2015EO028095. Published on 20 April 2015.

Text © 2015. The authors. CC BY-NC 3.0
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