Citation

It is an honor to introduce Peter Ulmer, one of the winners of the 2022 Norman L. Bowen Award of the AGU Volcanology, Geochemistry, and Petrology section. Peter’s breadth of approaches spans experimental petrology, field geology, and magma rheology in a truly exceptional way. Peter started as a field petrologist working on hydrous plutonic rocks in the Alps. The difficulty in retrieving petrological system variables in hydrous magmatic systems and understanding the role of water in magmas inspired his groundbreaking experimental studies ever since. Peter is widely known for exploiting fundamental questions by innovative and carefully designed experiments on subduction zone processes and magma generation and differentiation, with a great eye for big problems. His experimental demonstration of serpentine stability to mantle depth shaped research on volatile cycling in subduction zones for the past 25 years. His discovery changed the perception of hydrous arc magmatism and the subduction zone water cycle and inspired the development of novel experimental and analytical techniques on determining the composition of subduction zone fluids and melts around the second critical end point at high pressure. Peter explored the phase relations of multiply saturated primary hydrous basaltic magmas and their intermediate to felsic distillates that form much of the juvenile continental crust. By simulating both equilibrium and fractional crystallization, Peter showed that fractional crystallization provides in many cases a much closer match to natural rocks, most notably for arc lower crust. The full breadth of these results on transcrustal magmatic systems is yet to be explored. Moreover, Peter’s work on the rheology of particle and bubble-bearing magmas experimentally demonstrated the non-Newtonian behavior of crystal-rich magmas, with implications for the quantitative modeling of magma conduit processes, including the important effects on volatile exsolution. In addition, and perhaps even more important, Peter is a brilliant mentor for Ph.D. students and postdocs, and—rare in academia—incredibly modest. He is an inspiration for young scientists and an extraordinary fount of knowledge on all matters experimental. The diversity, rigor, and creativity in Peter’s experimental research are an extraordinary match to Bowen’s legacy.

—Othmar Müntener, University of Lausanne, Lausanne, Switzerlan

Response

Thank you, Othmar, for the kind citation and for more than 20 years of intense and fruitful collaboration and friendship. Thanks to those who supported my nomination and the Volcanology, Geochemistry, and Petrology Award Committee for selecting me. I am truly honored and humbled to receive the Bowen Award.

Of course, this is more than honoring an individual but a career based on interaction and collaboration with numerous mentors, peers, and students. Volkmar Trommsdorff, Alan Thompson, and Ezio Callegari, all experts combining field, geochemistry, and petrology, introduced me as a student at ETH Zurich into the challenging world of petrology. Studying the Adamello plutonic complex in the Southern Alps, I realized that unraveling the formation of arc-related rocks requires more than conducting fieldwork and analyzing rocks. Alan nudged me to study The Evolution of Igneous Rocks by Bowen, which I did with limited motivation considering the “ancient” publication date. This, however, completely changed my view on how to tackle igneous rocks based on profound knowledge of phase equilibria representing the thermodynamic control on evolution and composition. Understanding arc petrogenesis requires fundamental understanding of phase relations in hydrous systems from magma generation in the mantle to differentiation and emplacement in the crust. This motivated me to apply for a postdoc at the Geophysical Laboratory, allowing me to learn the trade of experimental petrology from the very experts. Bjorn Mysen, Ikuo Kushiro, Neil Irvine, Hatten Yoder, and Joe Boyd are ultimately responsible for turning a “field guy” into something like an experimental petrologist, both intellectually and technically, and deeply influenced the way I perceive igneous processes. Back at ETH, I had the opportunity to expand the existing experimental petrology lab together with Max Schmidt and Stefano Poli constituting the nucleus of what became an established experimental lab. Thank you for your continuous support and friendship.

The generous support by ETH allowed me to conduct research in the most unrestricted way and in close collaboration with great colleagues, postdocs, and motivated students. This included field campaigns to some of the most amazing places such as the Kohistan arc with Jean-Pierre Burg, Patagonia with Othmar and Lukas Baumgartner, and the Sierra Nevada with Tim Grove and Tom Sisson. Keeping a firm grip to the “ground” in the realm of real rocks is essential to identifying crucial processes and unresolved questions in Earth sciences and nourishes my fascination and passion to contribute to resolving the mysteries of continental crust formation.

—Peter Ulmer, Institute of Geochemistry and Petrology, Swiss Federal Institute of Technology (ETH) Zurich, Zurich, Switzerland

Citation

Mike Walter is an experimental petrologist who, like Bowen, asks major questions about Earth. His career began with the resolution of a large number of questions surrounding the compositions of melts and residue produced during partial melting of upper mantle peridotite. Starting with a simplified system, Mike elucidated the key melting reactions; the stability fields of garnet, plagioclase, and spinel; and the changing compositions of melts with increasing pressure and temperature. His paper is an experimental classic, painstaking in execution, remarkably rich in detail and insight. It provided a powerful framework for the interpretation and extrapolation of data on the more complex natural systems that he addressed next. Mike showed that partial melts of fertile peridotite shift from basaltic at low pressure through picritic to komatiitic at approximately 6 gigapascals. In this paper (1998) he also showed the compositional relationships between melts and peridotitic residues for carefully estimated fractions of melting. This is still the classic and definitive work on the pressure dependence of anhydrous peridotite melting (>1,100 citations).

Mike was the first to demonstrate the profound effect of pressure on core-mantle partitioning of nickel (Ni) and cobalt (Co). This led to the model of core segregation at the base of a deep magma ocean, the now generally accepted explanation for the apparent overabundance of siderophile Ni and Co in Earth’s mantle.

Moving into the lower mantle, Mike’s paper on trace element partitioning between perovskite and silicate melt (2004) showed that despite numerous assertions to the contrary, there was no isolation of a large perovskite-rich reservoir in the lower mantle at the end of the magma ocean phase of Earth’s accretion. The need for natural samples to compare with experiments led him into the study of inclusions in superdeep diamonds. In 2011, Mike showed that compositions of some inclusions matched precisely those expected for minerals formed from oceanic crust subducted into the lower mantle. When coupled with isotope measurements indicating formation of the diamonds from surficial carbon, this provided the first direct evidence that surface material is subducted to these depths and later exhumed. This and his succeeding studies on diamond inclusions have had a remarkable impact on our perceptions of both Earth’s convective cycle and the deep carbon cycle, providing some of the only direct constraints on both processes. Cast from the same mold as Bowen himself, Mike Walter asks the important questions and gets the right answers.

—Bernard J. Wood, University of Oxford, Oxford, U.K.

Response

I thank Bernie Wood for his gracious citation, the generous colleagues who gave their precious time to support my nomination, and the Volcanology, Geochemistry, and Petrology committee for acknowledging me when there are so many worthy folks in our community. I am ever thankful for the scientific and personal freedoms I have enjoyed throughout my journey, especially when these gifts are not available to everyone. No one achieves anything without the help and encouragement of others, and there are so many people who have taught, guided, and supported me along the circuitous path I have trodden across three continents. It would be impossible to name each in the space available, and I sincerely thank all of you. Yet there are those whose indelible imprint must be highlighted: Harmon Maher for believing in a late-blooming kid; Dean Presnall for instilling a deep respect and understanding of the power of phase equilibria as a tool for problem-solving in the tradition of Bowen; Ikuo Kushiro for inviting and welcoming me to the high-pressure paradise that is Japan and encouraging me to explore new horizons while tolerating my many egregious shitsugen; Eiji Ito for his kindness and for revealing the dark arts of the multianvil; Dave Walker for letting me in on his “rules”; my most excellent colleagues and friends in Bristol and throughout the United Kingdom from whom I learned and gained immensely, both scientifically and personally, not to mention the many poker nights at Blundy Towers when petrology and straight flushes comingled like crustal magmas; and not least of all the many outstanding students and postdocs who have done the lion’s share, kept me on my toes, and made synchrotron trips so enjoyable. It has been a great privilege to work at the institution that crystallized Bowen himself, first as a postdoc at the Geophysical Lab when Yingwei Fei gave me carte blanche in his high-pressure lab allowing me to become truly independent. I am grateful to my colleagues at Carnegie for welcoming me back into the fold after many years in exile and for their boundless scientific curiosity and enthusiasm. Science has evolved tremendously over the decades, becoming necessarily multidisciplinary to answer the complex questions of planetary formation and evolution. I can only imagine what Bowen would do with the tools and diversity of talented people we enjoy today to explore the Earth, planets, and new worlds beyond our solar system.

—Michael J. Walter, Carnegie Institution for Science, Washington, D.C.

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Graham Pearson and Mary R. Reid received the 2019 Norman L. Bowen Award at AGU’s Fall Meeting 2019, held 9–13 December in San Francisco, Calif. The award recognizes “outstanding contributions to the fields of volcanology, geochemistry, and petrology.”

Citation

Graham Pearson merits the 2019 Norman L. Bowen Award for adding to our fundamental understanding of igneous processes in the upper mantle through studies of volcanic rocks, exhumed mantle sections, subcontinental mantle samples, and diamonds and their inclusions. Pearson has tackled the major topics in mantle geochemical evolution with a research tool kit that ranges from petrography, mineralogy, and petrology through stable isotopes, radiogenic isotopes, siderophile elements, and spectroscopy. In using these techniques, Pearson has sought new analytical method developments that push the frontiers of analytical sensitivity and precision.

Colleagues will remember a long list of discoveries: large pieces of Earth’s mantle emplaced from the diamond stability field; eclogite xenoliths in kimberlite as Archean subducted oceanic crust; continental mantle keel age-match with overlying crust; Re-Os sulfide age-dating of single sulfide inclusions in diamond; kimberlite derivation from unique mantle sources; the Os isotopic imprint in the oceanic mantle of continental crust extraction; trace element abundances in gem diamonds and source fingerprinting; a modern subduction analogue for Archean craton formation; and the finding, in a superdeep diamond, of the first terrestrial ringwoodite.

In this latter accomplishment, we see a typical example of why Graham Pearson is especially deserving of the Bowen Award. He led the effort to successfully measure the water content of a delicately metastable single grain of ringwoodite while it was encased in the diamond so it could avoid breakdown and thereby retain all of its original water. In perhaps one of the most important mineral analyses ever made, Pearson and coworkers were able to show directly that the ringwoodite had approximately 1.5 wt % water. For the first time, here was confirmation that the mantle transition zone can be wet.

In consideration of the sum and variety of his contributions, we deservedly honor Graham Pearson for the wide interdisciplinary influence of his work in understanding the mantle at all depths.

—Steven B. Shirey, Carnegie Institution for Science, Washington, D.C.

Response

Thank you, Steve, for your very generous and flattering words. Thanks also to those who nominated me for this award. I am rather humbled by your faith in me. I have just two things in common with Bowen: my Canadian citizenship and time spent at the Carnegie Institution of Washington. I strongly recommend both.

My career has been blessed with a series of fortunate events and fruitful collaborations with a long list of talented people too numerous to mention but too important to ignore. On entering university, I wanted to be a mining geologist—something I still pretend to be when visiting diamond mines—but inspiring undergraduate teaching by Bob Thompson at Imperial College diverted my path. Having two amazing Ph.D. supervisors in Pete Nixon and Gareth Davies was key in pushing me on my way through life. Pete’s infectious fascination with the mantle and his personal integrity are something to aspire to.

Postdoc mentors of the stature, quality, and generosity of Steve Shirey, Rick Carlson, Joe Boyd, and Chris Hawkesworth gave me no excuse to fail. After 15 happy years at Durham, I was lured to Canada, where I am blessed with truly supportive colleagues who make working at the University of Alberta an absolute pleasure.

But I want to end by focusing on a group of people who often do not get the credit they deserve. Without the dedication, enthusiasm, and support of the lineup of lab managers and technical support I have been fortunate to work with through my career, I would have produced very little. So I’d like to acknowledge Geoff Nowell, Chris Ottley, Sarah Woodland, Yan Lou, and Chiranjeeb Sarkar, who, along with all of my students and postdocs, and my heroic wife, Sam, rightfully own some part of this award.

—Graham Pearson, University of Alberta, Edmonton, Canada

Graham Pearson and Mary R. Reid received the 2019 Norman L. Bowen Award at AGU’s Fall Meeting 2019, held 9–13 December in San Francisco, Calif. The award recognizes “outstanding contributions to the fields of volcanology, geochemistry, and petrology.”

Citation

Mary Reid is receiving the Bowen Award for her creative and innovative application of zircon geochronology for understanding active silicic magma systems. Her 1997 paper in Earth and Planetary Science Letters, “Prolonged residence times for the youngest rhyolites associated with Long Valley caldera: 230Th–238U ion microprobe dating of young zircons,” launched a new area of inquiry into magmatic processes, presenting both the analytical and intellectual framework for conducting and interpreting the geochronology of young zircon by secondary ion mass spectrometry. The unique and groundbreaking insights of this paper shifted our understanding of the rates and processes involved in magma storage, recharge, and eruption.

Mary used U–Th disequilibrium dating to show that zircons contained within the products of a single eruption have ages that span tens to hundreds of kiloyears, implying a complex and protracted preeruption history of subvolcanic magmatic evolution. Were the zircons recording the residence time of melt-rich and potentially eruptible magma (her preferred interpretation at that time), or were zircons being recycled from largely solidified parts of a much broader magma reservoir? These questions in turn spurred efforts by the modeling community to explore the conditions required to maintain melt-rich, silicic magma over these timescales and parallel efforts to understand the processes and timescales of silicic melt segregation from crystal mush. Mary’s work subsequent to the 1997 paper, both on her own and with her students, on Long Valley, Yellowstone, and the Youngest Toba Tuff, represent collectively a tour de force of insights into the operation of large, hazardous silicic magma systems. These papers, along with the many papers by other researchers using her techniques, have revealed subvolcanic magma systems to be dynamic, long-lived, and complex environments. Mary Reid’s work on silicic magma systems has had an enduring impact on the volcanology, geochemistry, and petrology fields. She is deserving of the Bowen Award in every respect.

—Jonathan Miller, San José State University, San Jose, Calif.

Response

A heartfelt thanks to AGU for the Bowen Award, one that carries a name known to every student of geology! I am truly honored and humbled. Thanks in particular to you, Jonathan Miller, for nominating me, and to Olivier Bachmann, Calvin Miller, and Tom Sisson for writing thoughtful—apparently!—letters of support. The four of you, and innumerable other scientific colleagues and friends, have made adventures in the world of geochemistry and petrology lively, provocative, and gratifying.

I have been continually intrigued by the generation and storage of magmas and by developing new approaches for our understanding of them. It has been gratifying therefore to watch myriad new insights unfold as our scientific community unlocked the clocks stored within individual crystals. I am indebted to Jim Gill, who first introduced me to U-series disequilibrium dating, and to Tim Grove, Stan Hart, and Nobu Shimizu, who encouraged me to pursue research independently and inspired me with their diverse approaches to dissecting complex geologic problems. The University of California, Los Angeles gang of Mark Harrison, Kevin McKeegan, and ion microprobe whiz Chris Coath created the intellectual and technical environment that made it possible for me to tease tiny time signals from micron-scaled domains within minerals. Working with and nurturing the careers of many talented graduate students have been the proverbial gifts that keep on giving, especially as they keep me honest about magmatic processes. In the context of this honor, I particularly want to acknowledge Wendy Bohrson, Kari Cooper, and Jorge Vazquez. Finally, my life would not be complete without my family: Jim Sample, Caitlin Sample, Jane Reid, Janne Blichert-Toft, and Francis Albarede. You are my trusted supporters, critics, and companions, always encouraging me to look beyond the horizon.

—Mary R. Reid, Northern Arizona University, Flagstaff

Tim Druitt and Steven Goldstein will receive the 2018 Norman L. Bowen Award at AGU’s Fall Meeting 2018, to be held 10–14 December in Washington, D. C. The award recognizes “outstanding contributions to volcanology, geochemistry, or petrology.”

Citation

Tim Druitt has made many fundamental contributions to petrology and volcanology. Tim displays breadth and originality and in the past several years has been a key figure in the revolution in understanding how rapidly large silicic magma chambers are assembled before eruption. His research is characterized by meticulous petrological observations, astute analysis, and interpretative originality. His contributions include masterly elucidation of the geological history of Santorini volcano; pioneering work on the geology of ignimbrites; novel laboratory and modeling studies of pyroclastic flow and debris avalanche dynamics; contributions to understanding caldera formation; insightful studies of Vulcanian explosion dynamics at Soufrière Hills volcano in Montserrat; and exceptionally high quality volcanological, petrological, and geochemical studies of the products of explosive caldera-forming eruptions, notably at Mount Mazama and Santorini.

Tim has had a recent burst of originality through his exhaustive petrological studies of Santorini rocks, focusing on the Minoan eruption. He has used diverse modern petrological methods to extract a compelling explanation of how large silicic magma bodies are assembled before major explosive eruptions. This work is a game changer showing that very large volumes (many cubic kilometers) of silicic magma are transferred into the upper crust in a remarkably short time (less than a few centuries). A series of recent papers with students and collaborators, starting with the already seminal 2012 Nature paper, have developed a new paradigm based on detailed geological characterization of the Minoan deposits, melt inclusion studies, use of major and trace element zoning patterns as a geochronometer to constrain crystal residence times, and experimental studies. This work demonstrates the rapid assembly of the Minoan chamber within a few centuries with the silicic melts originated from deeper sources in the middle crust. Last but not least, Tim is well known for his calm, collaborative, and collegial approach to science and to mentoring students.

—Steve Sparks, University of Bristol, Bristol, U.K.

Response

I am truly honored to receive the Bowen Award. Thank you, members of AGU, and thank you, Steve, for your kind nomination. Several people had a big impact on me during my early career. As an undergraduate I was particularly influenced by the late Stuart Agrell, and then as a master’s student by Roger Powell. Steve Sparks took me on as a research student and taught me to view volcanic systems holistically, to try and always quantify, and to make research fun. Working with Fred Anderson in Chicago exposed me to melt inclusions and to Fred’s profound insight into magmatic processes. During my postdoctoral fellowship at Menlo Park, Charlie Bacon convinced me of the benefits of persistent, focused studies of single volcanic systems. Doing research first in the United Kingdom, then at the U.S. Geological Survey, immersed me in the two great schools of explosive volcanism. My own approach has been to try and address fundamental questions on magmatic systems while having a long-term laboratory volcano, Santorini, to guide me in those questions and to test hypotheses. I have found this dual approach to be both productive and intellectually satisfying. It has allowed me to constantly learn new techniques, to collaborate with great people with skills different from my own, and to advance incrementally in the understanding of my chosen volcanic system. Throughout, my wife, Mary, and daughter, Fabienne, have kept me sane in a wonderful family life and put up with my many absences. I have enjoyed working with a team of fantastic Ph.D. students, postdocs, and colleagues who have taught me a great deal. Being paid to do research with bright and motivated people who share my curiosity for the natural world is a remarkable thing. I gratefully accept this award on their behalf, as well as on my own.

—Tim Druitt, University of Clermont Auvergne, Clermont-Ferrand, France

Citation

For what accomplishments has Steve Goldstein received the Bowen Award? The answers from the community would be diverse. For paleoceanographers, it would be because he pioneered Nd isotopes as an ocean circulation tracer. For those interested in continents, it would be his contributions to understanding continental growth. For mantle geochemists, it would be about the origin of mantle isotope heterogeneity and processes at ridges and convergent margins. Across these communities, the view would be that the honor was overdue, while knowledge of his contributions in other areas would be unlikely to be fully appreciated. Steve’s breadth was evident as a graduate student, with his papers using Nd isotopes in river sediments to constrain continental growth, the “mantle plane” Nature cover that first identified clear systematics of mantle isotope components, and his use of authigenic minerals to constrain seawater isotopic compositions. He followed with a productive decade in the Max Planck geochemistry group, where he and Nick Arndt proposed continental delamination as a major factor in continental growth and mantle heterogeneity, did important work on ocean island basalts, and showed that enriched magmas form an important part of the continental crust. His Aleutians work was among the first to demonstrate multiple distinct components coming from the slab. Returning to Lamont, Steve showed great persistence in developing Nd isotopes as a definitive measure of circulation, showed how ocean ridge basalts are consistent with an origin of mantle heterogeneity by low-degree melt metasomatism, and co-led the Dead Sea Drilling Project. Through these diverse contributions, Steve has demonstrated creativity and rigor and acted as a generous collaborator and mentor. We would all become broader and better educated if we were to familiarize ourselves with Steve’s work beyond our own specialties. For his diverse and fundamental contributions across an amazing range of disciplines, Steve is an outstanding Bowen Award recipient. —Charles Langmuir, Harvard University, Cambridge, Mass.

Response

Thank you, Charlie; I am awed and humbled by your kind words. As a VGP member, I’ve always considered the Bowen Award to be the best of the AGU awards, reflecting recognition by our closest colleagues. And I’ve figured that the very reasons listed by Charlie would exclude me from ever receiving it. A great aspect of geochemistry is that it impacts virtually all the other Earth and space science (ESS) disciplines. As a result, VGP is the AGU section with the broadest ESS impact, whose universality should be valued. I was lucky that when I joined AGU, doing geochemistry meant joining VGP, while today the choice is more difficult. Geochemistry offers great opportunities, for fieldwork all over the world, to learn about and address a wide range of topics and to work with amazing scientists to make important contributions across disciplines. This keeps geochemistry exciting; there are always new things to learn about and do. And it’s remarkable that geochemistry works so well; it’s almost guaranteed that the right questions combined with the right analyses will lead to interesting results. On the other hand, life and career carry no guarantees, and mine have been marked by serendipity; for example, entering Columbia by accident as a junior undergraduate and then discovering Lamont, which was then and is now an amazing, interdisciplinary place, where opportunities for exciting new scientific explorations constantly come at you. It was serendipitous to spend 11 years at the Max Planck Institute in Mainz, Germany, where Al Hofmann created a mecca for geochemistry, with amazing colleagues, and where the world’s greatest geochemists regularly visited. I’ve been privileged to have great mentors, colleagues, postdocs, and students, who have taught me more than I’ve taught them. And serendipity is having a great family, who above all deserve great thanks for putting up with me. —Steven Goldstein, Lamont-Doherty Earth Observatory, Columbia University, Palisades, N.Y.

Craig Manning and Bernard Marty will receive the 2017 Norman L. Bowen Award at the 2017 American Geophysical Union Fall Meeting, to be held 11–15 December in New Orleans, La. The award recognizes “outstanding contributions to volcanology, geochemistry, or petrology.”

Citation

At a time when many of us focus on models of multidimensional chemical systems, pursue the first measurements of new isotope systems, analyze ever smaller samples, or write short, “silver-bullet” papers, Craig Manning brings exceptional rigor and simplicity to experimental geochemistry. As a result, his experimental results are timeless benchmarks for future work. The same results are timely contributions to understanding complex topics such as the evolution of aqueous fluids in subduction zones, and speciation in fluids at high pressure. This is a unique combination. In his dedication to a simple, physical chemistry approach, Craig stands alone among his generation of experimental petrologists. His insight into design of single-phase solubility experiments, and their application to multiphase, multicomponent systems, is unmatched. Craig’s work calls to mind the giants of experimental geochemistry: Norman Bowen, who merged observational geology with the rigor of chemical thermodynamics; George Kennedy, whose experiments brought similar discipline to hydrothermal systems; Hal Helgeson, who, like Bowen, brought physical chemistry to bear on the study of water–rock reaction; and Bruce Watson, whose innovative experiments showed a generation how mineral solubility data could be applied to real geologic problems. Craig is a sought-after and conscientious advisor, with many first-author papers by his students. He is an experienced field geologist who spent many seasons in Greenland and the Himalaya. He has published more than 95 papers during this century, so one might expect him to be something of a nerd. Yet this is far from the truth. Craig’s wife, Becky, is an accomplished filmmaker, producer, and professor at UCLA, and he spends much more time socializing with Becky’s interesting colleagues than with boring geoscientists. He’s a great reader, a generous friend, and a sophisticated traveler. Craig brings honor, credibility, and style to the Bowen award, AGU, and geoscience in general.

—Peter Kelemen, Columbia University of New York

Response

Thank you, Peter. Your eclectic list of geochemical greatness emphasizes my convoluted path, starting with Bowen’s The Evolution of the Igneous Rocks, assigned by Barry Doolan for my undergrad petrology class at the University of Vermont. I was hooked from the first phase diagram and probably should have foreseen my future as an experimentalist. Instead, I went to Stanford to work on ophiolites with Bob Coleman, then with Dennis Bird, who was rigorously applying thermodynamics to the fossil hydrothermal systems of East Greenland. I got hooked on that too, and we had so much fun discovering how they worked while defending ourselves in the Arctic. A newly minted aqueous geochemist cannot fail to notice the complex high-pressure veining of the Franciscan Formation, but it was frustrating to discover that the beautiful Helgesonian framework for solutes only worked to 5 kilobars. I persuaded Steve Bohlen to take me on for a postdoc at the U.S. Geological Survey. His enthusiasm and willingness to try anything spurred my initial attempts to measure high-pressure quartz solubility in water while I was not working on other things. I was too dumb or obstinate to accept the many failures. Finally, enough capsules held that upon arriving at UCLA I repurposed Art Montana’s piston cylinders for their true calling: determining high-pressure mineral solubility in fluids. Bob Newton eventually joined the fray; he has provided constant inspiration and lasting friendship. Meanwhile, An Yin and Mark Harrison indulged returns to my field roots in the deserts of central Asia. Like so many past recipients of this honor, I can testify that traveling the anastomosing paths of field and experimental study will always reward. Thanks to all of you, to my parents for creating a family of Earth and environmental scientists, and to Becky for companionship, insight, wit—and friends.

—Craig Manning, University of California, Los Angeles

Craig Manning and Bernard Marty will receive the 2017 Norman L. Bowen Award at the 2017 American Geophysical Union Fall Meeting, to be held 11–15 December in New Orleans, La. The award recognizes “outstanding contributions to volcanology, geochemistry, or petrology.”

Citation

Bernard Marty has made major contributions to our understanding of the origins of volatile elements in the terrestrial planets. One could perhaps highlight four areas, centered on neon, carbon, nitrogen, and xenon. In parallel with Sarda and others, he showed that the neon isotopic composition of oceanic basalts is light relative to the atmosphere and argued that either the atmosphere was residual to a major fraction of lost volatiles or it was added later. He went on to show that some plume basalts have even higher 20Ne/22Ne than previously thought and used this to argue for a component of solar neon in the Earth. Using C/3He ratios of basalts, he estimated the mantle budget for carbon and demonstrated that budgets in arcs are dominated by recycling. With Dauphas he also made the observation that the nitrogen budget of oceanic basalts correlates with 40Ar/36Ar and used this to infer that nitrogen in the mantle was dominated by subduction of clays. He also made groundbreaking discoveries of the zoned nitrogen isotopic composition of the solar system based on Genesis samples. What is most spectacular is his recent work on xenon, where he and his team have made major inroads into long-standing problems. Working on early sediments, he found evidence that the fractionated isotopic composition of the atmosphere has become more so over time and reflects progressive losses, possibly from early UV irradiation. His well gas studies resolved chondritic xenon in the mantle. Finally, with analyses from Comet 67P sampled by Rosetta, he showed that Pepin’s original prediction of U-Xe, the anomalous isotopic composition of Earth’s primordial xenon, is a feature of comets, adding powerful new evidence for a cometary component in heavy noble gases. For these and other contributions, Bernard Marty is an extremely worthy recipient of the 2017 Bowen Award.

—Alexander Halliday, University of Oxford, United Kingdom

Response

I am deeply honored to receive the prestigious Bowen Award, and I would like to thank the people who nominated me, the awards committee and all at AGU, for their selfless efforts. I am particularly indebted to Alex Halliday, who has always been keeping his eyes wide open to the magical mystery tour that is the geochemistry of noble gases. I was first introduced to this marvelous field by Minoru Ozima in Tokyo, and I have been inspired by some prominent scientists along my way, including Francis Albarède, Chris Ballentine, Keith O’Nions, Yuji Sano, Igor Tolstikhin, and many others in Paris, Cambridge, and Nancy. I have had the chance to work with fantastic colleagues, students, and postdocs at Centre de Recherches Pétrographiques et Géochimiques (CRPG) Nancy, and especially with Pete Burnard, with whom we developed a state-of-the-art noble gas laboratory at CRPG. Pete was a great noble gas geochemist as well as a true human being. I thank Annie, Louise, and Edwige for personal balance in a life busy with science.

The noble gases are fantastic tracers whose chemical inertness and radiogenic isotopes provide a quantitative approach for investigating mass balance at planetary scales. Their origins in planets have been traced back, thanks to their diverse cosmochemical signatures. However, there remained the need to calibrate “useful” volatile elements, such as water, carbon, and nitrogen, to noble gases to gain insights into their origins and cycles, something I have tried to do throughout my career. Interestingly, none of my research has been directly related to mineralogy and petrology, so I feel particularly humble and blessed to receive an award named after a petrologist as great as Norman Bowen, illustrating to me the fact that in science, our tools do not represent the end of the story but are instead keys for unlocking some of the universe’s mysteries.

—Bernard Marty, University of Lorraine, Nancy, France

Dante Canil will receive the 2016 N. L. Bowen Award at the 2016 American Geophysical Union Fall Meeting, to be held 12–16 December in San Francisco, Calif. The award recognizes “outstanding contributions to volcanology, geochemistry, or petrology.”

Citation

The Bowen Award is presented to Dante Canil in recognition of his seminal work on the history of the oxygen fugacity of the upper mantle.
By the early 1990’s Fe3+/Fe2+ measurements of peridotites and MORB glasses indicated that the modern suboceanic mantle melts under oxygen fugacity conditions somewhat below the NNO buffer. But we knew little about the history of mantle oxidation state. Dante addressed this question by determining the partitioning of vanadium between olivine and silicate melt. He showed that the olivine-liquid partition coefficient DV decreases by more than an order of magnitude as the oxidation state of V increases from +2 to +4 with increasing oxygen fugacity. Thus, he demonstrated that Archaean komatiites (up to 3.5 Ga) crystallised olivine under fO2 conditions slightly below NNO and hence under similar conditions to modern oceanic basalts. His conclusion was “If the fO2 values recorded by basic magmas represent the fO2 of their mantle source region then the Archaean mantle source for komatiites is not likely to have been significantly less oxidizing than at present.” The important next step was to determine whether or not the Archaean mantle residue showed the same oxidation state as the lavas. Dante measured V partitioning into spinel, orthopyroxene, clinopyroxene and garnet. This enabled him to track V/Al ratios of peridotite residues from partial melting at different oxygen fugacities. He showed in this way that garnet peridotites from Archaean cratons exhibit melting depletions at oxygen fugacities about 1 log unit below the NNO buffer ie under similar conditions to those recorded by Archaean komatiites and modern oceanic basalts. Dante Canil’s groundbreaking work thus demonstrates that the oxygen fugacity of the upper mantle played no role in the rise of atmospheric oxygen and has remained approximately constant at the current value for at least 3.5 Ga.

—Bernard Wood, Oxford University, United Kingdom

Response

I thank Bernie Wood for this nomination, the Awards committee and all at AGU for their selfless efforts in adjudicating awards like these. How humbling such awards are. In a career one encounters so many other people to measure up to that it then becomes almost embarrassing to receive an award for what one loves to do. On this note I thank all those people I cannot name whose work I have read, learned from and aspired to match. Every neat idea I have had spawned from some isolated sentence in your paper. In my mind I share this award with you. I also thank those people who in some way took a chance on me along the way: Chris Scarfe, Dave Virgo, Fritz Seifert, Don Dingwell and Hugh O’Neill. I also thank my wife Terri and daughter Olivia for personal balance in a life occupied with science. I thank my parents for teaching me to balance modesty with pride, and to maintain a strong work ethic. I am a particularly honoured for this award because like Bowen, I am a Canadian, started geology in the bush and found myself in experimental petrology. Bowen saw how field observations could be later grounded in experiment. Nature is surely complex, and there are of course many more experiments to do, but they are not always sophisticated or expensive. Many of them require only imagination and paying attention to the work of others. For this reason, if you are a younger person in the audience I would urge you to not tow a party line, always look where your research speaks to other fields, and realize that you do not always need huge resources to make scientific progress. This has been my motto and I thank you all again for this incredible honour.

—Dante Canil, University of Victoria, Canada

Tim Elliott will receive the 2016 N. L. Bowen Award at the 2016 American Geophysical Union Fall Meeting, to be held 12–16 December in San Francisco, Calif. The award recognizes “outstanding contributions to volcanology, geochemistry, or petrology.”

Citation

Timothy (Tim) Richard Elliott is an isotope geochemist in the broadest sense of the term. After a PhD at Open University with Chris Hawkesworth as adviser, he went to Lamont as a post-doc and then to Amsterdam. He became a faculty at the University of Bristol in 1999. Dressing and chucking like a teenager but thinking and performing as a Jedi of Geochemistry, he combines, as his long-term friend Terry Plank puts it, “a child-like curiosity and generous mentorship with an utterly honest and brutal view of shabby work”.
Like a journeyman in previous centuries, Tim has gone through many of the basic techniques, learning to master neodymium, thorium-uranium, lead, nickel, magnesium, and tungsten isotopes with utmost proficiency before he tackled the most daunting challenges left unsolved by the pioneers of mantle and planetary geochemistry. He left his mark on a number of problems that have since become common knowledge, like the U-Th series in the Mariana volcanics as a marker of melting processes, the subduction factory, the history of the uranium cycle, and evidence of tungsten isotope heterogeneities attesting to live 182Hf in the early Earth. Tim is an unusual crossbred with outstanding analytical talent, rigor, and a deep understanding of the theoretical aspects of geochemistry. With Milton Keynes, Lamont, and Bristol efficiently nurturing Tim’s developing personality, his nature, that of a mind both independent and creative, rapidly revealed itself and has long since come into its own.

Time has now come to recognize Tim as one of the leading geochemists in his generation. Dear President and dear Colleagues, I am particularly proud to present to you the 2016 recipient of the Norman Bowen Award of the Volcanology, Geochemistry, and Petrology Section of the American Geophysical Union, Timothy Richard Elliott.

—Francis Albarède, Ecole Normale Superieure Lyon, France

Response

It is daunting to respond in black and white to Francis’ blushingly generous words. He has known me long enough to see more than just the questionable garb, so I am very grateful for his focus on the positive and longstanding support. Briefly wandering back down the memory lane Francis sketched, I think we are both misty-eyed about the excitement of research and life on the banks of the Hudson. To me this was certainly a fillip after the concrete cows of Milton Keynes, although this well-ordered suburban environment did inspire a comeraderie amongst the plucky few who chose to ask questions of Earth rather than estate agents. I remember the weekly window on a largely mysterious world provided by Eos, then in print form. This world, and indeed the bits I had never understood in Scooby Doo, were made gloriously manifest to me during my time at Lamont. Subsequently swapping Old for New Amsterdam seemed a fair exchange; I fear my lack of ostensible productivity during that era would be fatal now, but the freedom I was afforded for intellectual and technical rumination was enormously valuable. Thence my personal Brexit, which has proven to be the stuff of the impossible dreams of the Vote Leave campaigners.

I am hugely buoyed by the kind efforts of those who nominated me. Multitudinous thanks go out to the many who have helped me along a somewhat circuitous path and kept surprising faith in what I have been sometimes doing. I won’t name names, as the list would inevitably be both remiss and too long. Having spent much of my career assuming that the function of Awards Presentations was as a time out for much needed recuperation, I also appreciate the bravery of the committee for giving me a chance to engage.

—Tim Elliott, University of Bristol, United Kingdom

Thomas Sisson will receive the 2015 N. L. Bowen Award at the 2015 American Geophysical Union Fall Meeting, to be held 14–18 December in San Francisco, Calif. The award recognizes “outstanding contributions to volcanology, geochemistry, or petrology.”

Citation

Tom Sisson’s breadth of inquiry and approaches span volcanology, geochemistry, and petrology in a way that is truly rare. Tom is at once a creative and meticulous experimental petrologist, having done landmark work on the effect of water on the compositional evolution of magmas. He also is an innovative geochemical analyst, widely known for ground-breaking measurements on the preeruptive volatile contents of arc basalts. And he’s a prominent volcanologist, having made key discoveries in the study of Hawaiian and Cascades volcanoes while informing the public on their hazards. Tom is also a field geologist of exceptional talent, befitting the challenges of geologic mapping in the Sierra Nevada and at volcanoes such as Mount Rainier, arguably the volcano that poses the highest risk to communities in the conterminous United States. This background has guided his keen insights into magmatic processes from laboratory experiments and measurements anchored in ground truth from the field. Moreover, Tom’s Rainier papers serve as real-world examples of quantitative geoscience with societal relevance through application to volcano hazard evaluations. Tom’s work on the formation of granites, specifically how many steps are involved to create crustal distillates from primary mantle-derived basalt, will shape research and thinking into the next decade. Tom’s knowledge, gravitas, and generosity are also legendary. He is a caring mentor to young scientists, commonly at their side at meetings, listening patiently and then generously working through their problems, with considerable seriousness and substance though not without a sense of humor, helping to inform and inspire their science. When Tom speaks, it is with unusual clarity and confidence, and everyone listens. It is difficult to think of a modern scientist more deserving of Bowen’s legacy than Tom Sisson, in his foundational, high-impact, and diverse contributions to our understanding of magmas, from their origin to eruption.

—Terry Plank, Lamont Doherty Earth Observatory, Palisades, N.Y.

Response

Dear Terry, thanks for your considerate words and thanks to the anonymous colleagues who championed my nomination and to the Volcanology, Geochemistry, and Petrology awards committee. When I was a Stanford undergrad, Bob Compton assigned us Bowen’s The Evolution of the Igneous Rocks. I was convinced, and shortly after graduating, I bought a copy in New Zealand, where I was climbing in the Southern Alps. That copy accompanied me during my “living out of a VW bus and climbing” period, and I was slow to unlearn the few areas where Bowen was wrong. I’ve benefited from numerous inspiring mentors and colleagues, but Jim Moore and Tim Grove stand out. Jim gave me the precious opportunity to collaborate with him mapping a swath of U.S. Geological Survey (USGS) geologic quadrangles across the Sierra Nevada batholith, as well as studying the Mount St. Helens directed blast. Jim never worried too much if he was working on petrology, volcanology, glacial geology, or …, and I found this a good model to follow. Fieldwork only goes so far, so I went to work with Tim at the Massachusetts Institute of Technology because he addresses major scientific issues using the highest-quality experiments guided and tested insofar as possible by field observations. Having mapped numerous mafic intrusions in the Sierra, it seemed obvious and inescapable to me that basaltic arc magmas are wet (yes, this was once not known). We showed experimentally how this explains many aspects of arc magmas, shortly confirmed by my early ion probe measurements on basaltic melt inclusions. The USGS called me back, where I’ve continued mostly studying arc petrogenesis and hazards. The in-depth, place-based studies fostered by the USGS reveal how magmatic systems are at the same time complex and simple. Understanding controls on magmatic volumes, locations, and timing are some of the challenging and fascinating issues that I look forward to seeing addressed.

—Thomas Sisson, California Water Science Center, U.S. Geological Survey, Menlo Park

Mark Ghiorso received 2014 Norman L. Bowen Awards at the 2014 American Geophysical Union Fall Meeting, held 15–19 December in San Francisco, Calif. The award recognizes outstanding contributions to volcanology, geochemistry, or petrology.

Citation

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, TN

Response

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.

Richard O. Sack received 2014 Norman L. Bowen Awards at the 2014 American Geophysical Union Fall Meeting, held 15–19 December in San Francisco, Calif. The award recognizes outstanding contributions to volcanology, geochemistry, or petrology.

Citation

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

Response

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.

Donald B. Dingwell and James W. Head III received the 2013 Norman L. Bowen Award at the 2013 AGU Fall Meeting, held 9–13 December in San Francisco, Calif. The award recognizes outstanding contributions to volcanology, geochemistry, or petrology.

Citation

It is my privilege and honor to deliver the citation for Don Dingwell to receive AGU’s N. L. Bowen Award. Don’s research has profoundly influenced our understanding of the properties of silicate melts, glasses, and magmas and the fundamental control they exert on magmatic, volcanic, and, recently, even on earthquake processes. Don’s approach is experimental, and his studies have interrogated melts, glasses, and magmas for their transport, calorimetric, geophysical, and rheological properties, as well as the solubilities of volatile species. These experiments have been elegantly designed to elucidate properties that provide quantitative explanations for volcanic processes. He has a prodigious publication record, including many seminal “must-read papers,” as evidenced by any bibliometrics you choose. Indeed, his research has changed the very way we communicate about volcanic processes by expanding our vocabulary to include “glass transition” or “melt relaxation.” In many ways, his research career has established what is a new, unique, and expanding line of science—“experimental volcanology.”

Don’s success in research reflects three things. First, he has a native talent for creative experimentation. Even with all the budding superstars sequestered in the Munich labs, when something goes wrong, they go to Don. Don is always able to find a solution, often a workaround. Second, Don recognizes the truly important questions and designs innovative experiments for making the critical measurement. He also has an amazing talent for seeing the broader implications of unexpected experimental results for volcanic processes. Third, intrinsic to Don is his very generous spirit of cooperative and collaborative research—everyone is invited under his big tent of experimental volcanology. There is a constant stream of scientists passing through Munich to participate in experimental volcanology.

Please allow me to close with a few personal insights. With Don, there is no doubt of his passion for the volcanological sciences. One expression of this is his yearly Melts, Glasses, Magmas Workshop (since 2000), which serves our community very well. I had the pleasure of spending a sabbatical year at Ludwig Maximilian University of Munich (LMU) the year Don arrived there. Thus, I can appreciate what Don has built in the meantime. The LMU labs are the international destination for scientists interested in experimental volcanology. Don’s research group remains imaginative, inventive, and productive—and it is still expanding. It is a truly auspicious time for the Volcanology, Geochemistry, and Petrology section of AGU to be able to recognize Don and his achievements with the 2013 N. L. Bowen Award.

—KELLY RUSSELL, University of British Columbia, British Columbia, Vancouver, Canada

Response

Thank you, Kelly!

To all who were involved in this selfless process of nomination, evaluation and selection, thank you for your voluntary efforts.

To Dave Strong, Chris Scarfe, Hat Yoder, Fritz Seifert, and others who took a look at me at some point and thought they saw some potential, thank you for the trust.
To the University of Munich, the Free State of Bavaria, the Federal Republic of Germany, and the European Union, thank you for the generous support that has allowed us to compete with so many bright young Americans.

Ultimately, as a university professor, one tries to catalyze the advancement of ideas and people. In doing so, one is sometimes catalyzed oneself. For the countless catalytic experiences of my research career, I wish to thank Lesley, Hugh, Dave, Chris, Mark, Dave, Bjorn, Jim, Sharon, Alex, Ruth, Nick, Francois, Michel, Pascal, Yan, Sumit, Harald, Eleonora, Fritz, Annibale, Hugh, Herbert, Werner, Jim, Mike, Guy, Tom, Richard, Martin, Philippe, Claudia, Kai, Alex, Mikhail, Markus, Frank, Joan, Jim, Olli, Ilya, Detlef, Jo, Paul, Mark, Caroline, Daniele, Klaus, Conrad, Kelly, Andreas, Sophie, Ulli, Paolo, Betty, Hugh, Gabriele, Sebastian, Alex, Mette, Soren, Ben, Jacopo, Piergiorgio, Brent, Cristina, Lothar, Locko, Marcel, Jon, Annarita, Roman, Cliff, Diego, Benoit, Yan, Yan, Phil, Jo, Daniele, Annika, Miguel, Rita, Simon, Silvio, Alessandro, Jackie, Guilhem, Tom, Oryaelle, Stefan, Cristoph, Paul, Pierre, Phil, David, Sebastian, Audrey, Alejandra, Corrado, Fabian, and Jeremie. (Any omissions are my fault!)

For the core members of the Munich team who have my back covered when I am called to other duties—Betty, Ulli, Corrado, Kai, and Werner—thank you. You have taught me a lot about loyalty and teamwork.

I thank especially all of those young researchers who are making these years the most exciting and productive scientific experience of my life.
If you are in the first decade of your career here tonight, then I can promise you, in volcanology, geochemistry, and petrology, the best is yet to come—stick with it.

To Felix and to Anke, thank you for enduring the crazy life of a researcher.
I’d like to close by dedicating this award to all the first-rate scientists who are members of our community and who have not yet received such recognition.

—DONALD BRUCE DINGWELL, Ludwig Maximilian University of Munich, Munich, Germany

Donald B. Dingwell and James W. Head III received the 2013 Norman L. Bowen Award at the 2013 AGU Fall Meeting, held 9–13 December in San Francisco, Calif. The award recognizes outstanding contributions to volcanology, geochemistry, or petrology.

Citation

It is my pleasure to present James W. Head III of Brown University as a recipient of the 2013 Bowen Award. A major theme of Jim Head’s research career has been the unraveling of the volcanic history of the rocky bodies of the solar system, and he has been an investigator on virtually all of the major international planetary investigation missions. Jim is an excellent observer and interpreter of observations. But more than that, as I have observed over our long history of collaboration, he shares the need to understand the basic physical processes controlling volcanism and to interpret observations in a quantitative, as well as qualitative, way. So in addition to documenting the history of volcanism on silicate planets, Jim has been at the forefront of trying to understand the mechanisms of volcanic eruption processes, on Earth as well as elsewhere.

As part of his drive to maximize the return from spacecraft missions to the terrestrial planets, Jim has been instrumental in encouraging collaboration between planetary scientists across the globe, and as an example, I particularly mention the ongoing program of twice yearly microsymposia focusing on planetary science topics that Jim cofounded in the mid-1980s.

At Brown, nearly 40 graduate students have obtained their Ph.D. under his direct guidance, and of these, several have already obtained full professorial status in the planetary science field and many others are at various points in successful careers in planetary research. The inspiration that Jim has engendered in these people, as well as the many undergraduates he has mentored at Brown, is self-evident.

In summary, Jim Head has been, and continues to be, a powerhouse of inspiration to, and productivity in, the planetary volcanology community, and it is clear that he is very worthy of the Norman L. Bowen Award.

—LIONEL WILSON, Lancaster University, Lancaster, UK

Response

Thank you, Lionel, for your kind words. N. L. Bowen has been an inspiration to me since the first geology course that I took as an incoming freshman at Washington and Lee University. I had to take a science course for distribution requirements, and I discovered geology, where the laboratories were often outdoors and the Earth was your laboratory and inspiration! Geology seemed perfect for me: I could combine my love of the outdoors with an insatiable curiosity about what made things work. I was quickly overwhelmed, however, by the beauty and extreme diversity of rocks and minerals, so much so that it was beginning to seem like yet another foreign language to me. Then one day we discussed N. L. Bowen’s reaction series, and it all immediately started to make sense to me. This inspired in me a “systems approach” to understanding complex geologic processes and problems. It also compelled me to try to quantify all of the observations that contributed to understanding geological processes.

I want to thank Tom McGetchin for introducing me to quantitative physical volcanology, teaching me what the back of an envelope was really for, but, most importantly, teaching me to stop thinking and just take in the sensory awe of an active eruption. In the 1970s, I met Lionel Wilson and Sean Solomon, and my life changed. Sean introduced me to big questions, planetary interiors, thermal structure, and planetary thermal evolution. Lionel taught me the beauty of physics and how complex physical and geological processes can be modeled with the right combination of question-framing and observational input.

Thanks to my students, scientific colleagues, and collaborators and to the Apollo astronauts who warmly welcomed a young geologist who shared their passion for lunar exploration. I gratefully thank the Volcanology, Geochemistry, and Petrology section of AGU for this honor, named for the very first person I came to know in freshman geology.

—JAMES W. HEAD III, Brown University, Providence, R.I.

Yoshiyuki Tatsumi received the 2012 N. L. Bowen Award at the 2012 AGU Fall Meeting, held 3–7 December in San Francisco, Calif. The award recognizes “outstanding contributions to volcanology, geochemistry, or petrology.”

Citation

It is a pleasure to present to you the 2012 Bowen Award winner, Professor Yoshiyuki Tatsumi, of Kobe University. Yoshi is well-known because of his work over the last 30 years on magma genesis and solid Earth geochemistry. His approximately 115 papers have advanced our understanding of the sources of magma in arcs, ocean islands, and continental interiors; the role of fluids in the transfer of elements from subducted slabs into the mantle wedge; the differentiation of basalts; and how juvenile crust develops its seismic and chemical stratification through time. His work combines experimental petrology with trace element and isotope geochemistry.

Yoshi’s rise as a petrologist began as a student of Professor Ishizaka at Kyoto University, studying the geology and petrography of Setouchi high magnesian andesites, then high-P experiments in Ike Kushiro’s piston cylinder lab. He later spent 1 year each in Manchester and Hobart before working for 16 years at Kyoto University. As program director at the Institute for Frontier Research on Earth Evolution, he initiated interdisciplinary efforts in petrology, geochemistry, geophysics, and ocean exploration. He also served in many senior positions within the Integrated Ocean Drilling Program. Largely because of his leadership, 6 months of drilling related to volcanology, geochemistry, and petrology (VGP) objectives are now scheduled for the JOIDES Resolution in 2014. If we do use Chikyu to drill 5.5 kilometers into the middle crust of the Izu arc, it will be because of Yoshi’s dream and initiative.

In addition to being an excellent scientist, Yoshi is also a gracious host, an excellent cook, and a talented pianist. He was a star basketball player both in high school and at the Kyoto University. He has also played the important role of television scientist, teaching the public about our science. We hope he continues for many more years as a leader in our field.

—ROBERT J. STERN, University of Texas, Dallas

Response

Thank you, Bob, for your kind words. I am most grateful to everyone involved in the nomination and evaluation processes, the VGP section, and AGU for affording me this much-appreciated honor, the 2012 Bowen Award. Also, I would like to thank my seniors and many colleagues for sharing the fun of decoding how magmas form in the Earth’s interior.

The first target in my scientific career was unusually magnesium-rich andesites that occur on a small island in the southwestern Japan arc. Through this work, although it is still going on, I strongly recognized the importance of the local study with the global viewpoint. I also learned that multidisciplinary approaches, in addition to classic petrology, are needed for comprehensive understanding of magma genesis. These experiences greatly affected the later works on magma genesis in subduction zones and hotspots and led me to the fantasy of the subduction factory.

One of the great experiences for me is to have been able to work with those who are living on the continents, through staying in the United Kingdom and Australia and numerous meetings for IODPs (Integrated Ocean Drilling Program and International Ocean Discovery Program). I deeply acknowledge them, because they freed me from the island-country mentality, and I really hope to collaborate with them further, in order to understand how continents have been made in the ocean on this planet Earth.

—YOSHIYUKI TATSUMI, Kobe University, Kobe, Japan

James A. Connolly and Marc M. Hirschmann received the 2011 N. L. Bowen Award at the 2011 AGU Fall Meeting, held 5–9 December in San Francisco, Calif. The award recognizes "out-standing contributions to volcanology, geochemistry, or petrology."

Citation

It is an honor to introduce Jamie Connolly, winner of the 2011 N. L. Bowen Award of the AGU Volcanology, Geochemistry, and Petrology section. The Bowen award recognizes outstanding contributions in a paper or series of papers. On this basis, Jamie is doubly worthy of this honor.

Jamie Connolly is perhaps best known for creating and maintaining PERPLE_X, a package of computer codes modestly billed as having the purpose of “calculating and displaying phase diagrams, phase equilibria and thermodynamic data.” But Jamie showed us that there is more. By including key geophysical parameters, he linked petrology with geodynamical modeling of planetary interiors. Jamie’s approach has transformed our understanding of the links between petrology, seismology, and rheology in such important environments as subduction zones and the upper mantle.

Jamie Connolly has also made fundamental contributions in a second area: crustal fluid flow. He was among the first to understand and explore crustal fluid flow via the dynamical approach of Dan McKenzie, Frank Richter, Dave Stevenson, and others, on compaction and porosity waves associated with melt production and migration. Jamie showed that fluid expulsion during metamorphism or sediment lithification is governed by deformation through a rock’s resistance to compaction. He showed that, for compacting rocks, compaction can sustain high fluid pressure and lead to solitary waves of porosity that propagate independently of the reaction that produced the fluid. His contributions provided the first truly dynamic insights into this complex process.

In working at the interface between petrology and geodynamics, Jamie Connolly has advanced both fields through fundamental and rigorous contributions that offer deep understanding of crustal and mantle processes. It is this philosophy that spurred Norman Bowen, who would surely recognize a bit of himself in so accomplished a scholar as Jamie Connolly.

—Craig E. Manning, University of California, Los Angeles

Response

Thank you, Craig, for the kind citation. I am honored to receive the Bowen Award. An award makes you ponder your own merit, so the nice thing about it is the realization that someone else has gone to the trouble of doing that for you and decided favorably. I am grateful to everyone involved in the nomination and evaluation process, and the Volcanology, Geochemistry, and Petrology section, for allowing me to savor that realization. How did I get here? I wish I could say I had some grand scheme, but the path I followed is better described by the word career as a verb than as a noun. I cannot thank everyone who has helped me, so I will restrict myself to three individuals who determined the main directions of my careering. The first is Derrill Kerrick, my Ph.D. advisor at Pennsylvania State University. When I arrived at Penn State I was already fascinated by phase diagrams, but I thought it was a passion that should not be admitted in public. Without Derrill I would never have come out of the closet, nor would I have learned how to water ski or calculate seismic wave speeds. The second person is Alan Thompson, my postdoctoral mentor, whose swashbuckling cross-subdisciplinary raids made me realize that petrology, geodynamics, and geophysics are intimately related. Alan and Derrill introduced me to different worlds. Fourteen years ago, Yuri Podladchikov dragged me out of my office and began teaching me how to connect those worlds. I am pleased that he has not given up on that project. In closing, I acknowledge the Swiss Federal Institute of Technology (ETH) Zurich. It attracts outstanding students who have done much to educate me; and not only is it large enough that you can find the answer to any question there, but also it is large enough to tolerate my idiosyncrasies.

—James A. Connolly, Institute of Geochemistry and Petrology, Swiss Federal Institute of Technology (ETH) Zurich, Zurich, Switzerland

James A. Connolly and Marc M. Hirschmann received the 2011 N. L. Bowen Award at the 2011 AGU Fall Meeting, held 5–9 December in San Francisco, Calif. The award recognizes "out-standing contributions to volcanology, geochemistry, or petrology."

Citation

I am delighted and honored to give the citation for Marc Hirschmann’s Bowen award. Marc and I were graduate students together in Seattle, where he was advised by Mark Ghiorso. Marc achieved a Promethean feat as a postdoc, “carrying the flame” of techniques developed at Berkeley to Ed Stolper’s Harvard-trained group at the California Institute of Technology. Together, Hirschmann and Stolper wrote a classic paper on melting of mafic veins in the mantle. They showed that thermal diffusion into veins would offset the heat of fusion, leading to a superadiabatic PT path. This was unanticipated but seemed immediately obvious once stated.

Moving to Minnesota, Marc became an experimental petrologist and set out to quantify melting of mafic rocks under mantle conditions. Given the diversity of mafic lithologies, I was afraid that Marc would get lost. Instead he and his students delineated quantitative, general properties that apply to a wide range of compositions. The resulting data underpin much recent work on melting of two-lithology sources in the mantle.

Marc then investigated the effect of water and carbon dioxide on mantle melting, the latter mainly with Raj Dasgupta, also an exceptional scientist. Again, tackling this topic using natural compositions posed the risk of getting lost, but instead they discovered valuable guidelines.

Marc has become a sought-after expert on volatile cycling in the Earth. De facto, he has been appointed by consensus to a role that few attain, the small group whom we treat as authorities on the entire Earth system. It’s a select group, a really rare honor.

As a result of this success, achieved with grace and without rancor, Marc was called to fulfill many leadership roles in our community, for example, serving on the MARGINS Steering Committee. While generally I am not happy to be steered, I was relieved to see Marc in these roles and trusted him for unbiased, well-informed, proactive leadership.

I am honored to know Marc, and I feel privileged to have played a role in celebrating his well-deserved Bowen Award.

—Peter B. Kellemen, Lamont-Doherty Earth Observatory, Columbia University, Palisades, N.Y.

Response

I kind of took the long route to my career, so I don’t have time to mention everybody who inspired me. Were it not for Ian Carmichael, I wouldn’t have become a petrologist. I learned a ton about rocks and had great arguments with Charlie Bacon in two summers at Crater Lake. Mark Ghiorso taught me the interior secrets of quantitative petrology, and Ed Stolper’s high expectations showed me a new level of rigor and how to ask bigger questions.

At Minnesota they solved our two-body problem even though there was supposed to be one job. Then we showed up with an infant, and still they were more than welcoming to all three. There, I’ve benefited from the great mentorship of David Kohlstedt and Larry Edwards and from a string of students and research scientists who, of course, do most of the work: Maik Pertermann, Jen Engstrom, Raj Dasgupta, Sandeep Mukherjee, Travis Tenner, Fred Davis, Ben Stanley, Hongluo Zhang, Patrick Hastings, Johnny Zhang, Dimitris Xirouchakis, Tetsu Kogiso, Ken Koga, Tony Withers, Cyril Aubaud, Paola Ardia, Haijin Xu, Anja Rosenthal, and at least that many undergraduates. I could tell stories about them all, so I’ll just say that if it weren’t for Tony Withers, my research enterprise would be a total failure.

I think of geology as the family adventure, and so I’m grateful that Donna and Naomi are with me on the ride. And I’m humbled to receive an award given previously to so many illustrious people, and I feel particularly lucky that I’ve had the benefit of friendship with or mentorship from quite a few of them. I’m even more humbled when I think of some of my peers who have not received this recognition but are certainly more worthy than I.

Thank you.

—Marc M. Hirschamann, University of Minnesota, Minneapolis

Samuel Bowring and Hans Keppler each received the 2010 N. L. Bowen Award at the 2010 AGU Fall Meeting, held 13–17 December in San Francisco, Calif. The award recognizes "out-standing contributions to volcanology, geochemistry, or petrology."

Citation

It is a pleasure to recognize Sam Bowring, whose career achievements have been focused on a better understanding of Earth history. Bowring’s groundbreaking studies of the early Earth include the discovery and interpretation of the ›4.0 Ga Acasta gneisses and the demonstration of how cratons are assembled and stabilized based on integrated mapping, geochronology, radiogenic isotope geochemistry, and xenolith studies.

The Acasta gneisses, discovered by Bowring, are still the oldest recognized rocks on Earth and preserve clear evidence for its early differentiation. He was able to show that the Acasta gneisses are not anomalous with respect to either other Archean rocks or Proterozoic and Phanerozoic continental arc rocks. This interpretation required that massive crust­mantle differentiation occurred early, which in the late 1980s was considered a radical departure from the conventional view. Bowring’s original work should now be viewed as seminal in our understanding of the Earth’s early differentiation.

In subsequent work on the stabilization of cratons he turned his attention to regional studies of the Proterozoic orogenic belt of the U.S. Southwest and the Kaapvaal craton of southern Africa, in addition to the Slave craton. An important aspect of understanding the stabilization of cratons concerns their thermal evolution, and thermochronologic studies of lower crustal xenoliths were used to deduce their thermal histories, from assembly to growth of a cold, buoyant lithospheric root.

In summary, Sam Bowring is a pioneer in this field who has left an indelible mark on our understanding of the history of Earth and its biosphere. Sam, along with his students and postdocs, has amassed a compelling wealth of data that chronicles the processes and history of events involved in differentiation of the early Earth. Norman L. Bowen, dedicated experimentalist who cut his teeth on Precambrian rocks in the Canadian Shield, would surely applaud Sam Bowring’s receipt of the Bowen Award.

—John P. Grotzinger, California Institute of Technology, Pasadena

Response

Thanks, John, for the generous words. I met John on the shores of a mosquito and black fly infested lake in Wopmay orogen more than 30 years ago, and I was very happy to present today our most recent results from Wopmay. John, Kip Hodges, Tom Jordan, and Tim Grove convinced me to come to Massachusetts Institute of Technology (MIT), and I am still here, and grateful for my stimulating colleagues.

I arrived at the University of Kansas to work with Randy van Schmus, but before starting any work, I spent what was supposed to be 2 weeks with Paul Hoffman, Randy, and Robert Hildebrand in northwestern Canada that turned into 6 weeks, and then another 10 or so field seasons. Randy taught me about mass spectrometers and isotope geochemistry, and Paul tutored me in plate tectonics, orogenic belts, baseball, politics, and music.

Any success I may have had is due to the amazing group of graduate students and postdocs from whom I have learned. My graduate students at Washington University, the late Todd Housh, Kevin Chamberlain, Ann Heatherington, Clark Isachsen, Jesse Dann, and Mike Villeneuve kept the lab lively. At MIT, Mark Schmitz, Dave Hawkins, Julie Baldwin, Becky Flowers, Blair Schoene, Anke Friedrich, and Karen Viskupic were instrumental in pushing me in new directions, and my current group, including Noah McLean, Seth Burgess, Terry Blackburn, and Erin Shea, exerts relentless pressure on me to keep up. Postdocs and research scientists Dan Condon, Drew Coleman, Matt Rioux, Jahan Ramezani, Jim Crowley, Mark Martin, Frank Dudas, and Robert Buchwaldt have been a pleasure to work with, and together we have explored some very exciting science.

Thanks to the VGP Bowen Award Committee and AGU for this award and all those who have supported me over the years. I am truly honored.

—Samuel A. Bowring, Massachusetts Institute of Technology, Cambridge

Samuel Bowring and Hans Keppler each received the 2010 N. L. Bowen Award at the 2010 AGU Fall Meeting, held 13–17 December in San Francisco, Calif. The award recognizes "out-standing contributions to volcanology, geochemistry, or petrology."

Citation

Hans Keppler and his research have profoundly influenced our understanding of the physical and chemical properties of fluids in Earth's interior, their interactions with melts and solids, and their controlling influence on geochemical budgets and material properties, all with a global perspective.

In his research, Hans combines experimental innovation with technical skill to pursue in situ observations of critical phenomena and in situ measurements of properties of nonquenchable materials. One of Hans's important contributions has been measuring and systematizing bulk hydroxyl/water solubility in important minerals in the upper mantle and transition zone. He combined these data on individual minerals into a model for the maximum water content of rocks at these depths. In a recent paper in Science he elegantly provided an explanation for the existence of the asthenosphere by considering the water budget, an approach that explains the rather sharp upper boundary of the asthenosphere combined with a relatively diffuse lower boundary.

In closing, let me return to my opening comment, namely, that Hans and his research have had an impact on our science. About 15 years ago, I had the good fortune to spend a year in Bayreuth working with Hans and Dave Rubie. Being 20 years older than Hans, I thought I would be the teacher and he the student. Not so. I remember clearly working through some aspects of thermodynamics as applied to our research. It was absolutely clear to me that Hans knew the answers to the questions with which I was struggling. It was Hans who was the teacher and I the student, as he patiently led me to discover the answers for myself and, in so doing, helped me embrace a much deeper understanding than would have been possible had he simply provided the resolution without my participation in the process.

—David Kohlstedt, University of Minnesota, Minneapolis

Response

Thank you, David, very much indeed. Naturally, I feel deeply honored by the Bowen award, for two reasons. One is that the award is named after Norman Bowen, with whom I share many common beliefs, such as the belief in the need to carefully study simple systems and to fully understand the physicochemical principles behind Earth processes. The other is that this is an award of AGU. I owe a lot to America, and I would not be the person I am had I not spent 2 years as a postdoc at California Institute of Technology, working with Peter Wyllie and also with George Rossman.

In later years I benefited enormously from working with several people. I could now mention many names, but I will just mention two: Andy Shen, who introduced me to externally heated diamond anvil cells, and, of course, David Kohlstedt, who showed me the importance of water in olivine. When David came to Bayreuth, it was around the time of his fiftieth birthday. I looked at him and thought, "Wow, I have never seen anything like this before—a professor who is 50 years old and who is still doing his experiments all by himself!" This apparently left a long-lasting impression on me; today, my fiftieth birthday is not so far away, and I am still sometimes doing experiments all by myself—I hope that Norman Bowen would not be too disappointed about the way I do my experiments.

Thank you all again!

—Hans Keppler, Bayerisches Geoinstitut, Bayreuth, Germany

Tim Holland and Roger Powell received the 2009 Norman L. Bowen Award at the 2009 AGU Fall Meeting, held 14–18 December in San Francisco, Calif. The award recognizes outstanding contributions to volcanology, geochemistry, or petrology.

Citation

Tim Holland and Roger Powell receive the 2009 AGU N. L. Bowen Award for an outstanding contribution to petrology and geochemistry—the result of an ongoing collaboration begun in the early 1980s—that has changed the way we carry out quantitative phase equilibria studies. A quantitative understanding of chemical reactions among minerals, fluids, and melts requires accurate representation of their thermodynamic properties, making a compilation of these properties one of the most important data sets in petrology and geochemistry. The Holland and Powell collaboration has produced the most complete data set of thermodynamic properties of end-members of the phases required to perform calculations on the conditions of formation of rocks and their interactions with fluids and melts. The data set is internally consistent, meaning that all of the available information has been appraised and combined statistically (in a least squares sense), yielding uncertainties and correlations. This allows uncertainties on the calculated results to be obtained—an important element of the Holland and Powell approach. However, quantitative phase equilibria studies require more than just a statistical optimization of the thermodynamic properties gleaned from various sources (experimental, calorimetric, etc.), and Holland and Powell have developed formulations for appropriate equations of state, thermodynamic models to treat nonideal mixing properties, ways to estimate thermodynamic properties, and improvements to some classic nonideal formulations to expand their domain of validity. For example, a critical contribution has been estimation of the mixing properties of complex phases such as the chlorites, the amphiboles, and Na-K dominated melts. In turn, this has enabled phase equilibria calculations to be made for a wide range of rock and domain compositions.

Although the responsibilities of Holland and Powell within their collaboration are clearly defined and complementary, the body of work recognized by this award would not have been possible without the collaboration. Their collaboration has produced 35 papers, of which 19 are authored by Holland and Powell or Powell and Holland. Six papers explain the basis for the internally consistent thermodynamic data set, describe methods to use the data set for various calculations, and provide software to enable users to undertake these calculations for particular rock and domain compositions. Additional papers describe the ever more sophisticated activity-composition models. Furthermore, a thermodynamic data set must evolve or its usefulness will diminish. Holland and Powell have been indefatigable over the past quarter century in increasing the number of entries in the data set, refining the quality of the data and the activity-composition models, and improving their software packages, as well as making it all available free via the World Wide Web.

Given the complex nature of phase equilibria calculations, the provision of “industry standard” programs—AX and THERMOCALC—was critical to enabling all of us to undertake these calculations with minimum training. AX is a program that takes mineral analyses and calculates the activities of the mineral end-members useful for thermodynamic computations. THERMOCALC is a thermodynamic calculation software package for addressing mineral equilibria problems that may be used to undertake a wide range of phase diagram calculations, including P–T projections; P–T, P–X, and T–X pseudosections; compatibility diagrams; and µ–µdiagrams. Phase diagram computations for defined bulk and domain compositions made possible by THERMOCALC have enabled researchers throughout the world to make advances in understanding the thermal evolution and the burial/exhumation history of orogenic belts.

The variety of applications of the Holland and Powell “tools” is beyond belief, and the work cited for this award has pervaded our community from low-temperature geochemistry to mineral deposits geology and from high-pressure metamorphic rocks to crustal melting. Please congratulate the 2009 Bowen awardees, Tim Holland and Roger Powell.

—Michael Brown, University of Maryland, College Park

Response

I would like to say a big thank you to AGU, in particular to Alex Halliday and the Volcanology, Geochemistry, and Petrology (VGP) group, for the honor of being granted the Bowen Award jointly with Roger Powell. It came as a great surprise (and a delight)—particularly cheering was the mention of it as a “midcareer” recognition! Thank you, Mike, for your kind words on our behalf, in your citation, and particularly for the way you have supported and encouraged us in our work over the years.

I would like to take the opportunity to thank several individuals among many who have been significant in my geological career. It was Steve Richardson, a bright and gifted lecturer at Oxford, who inspired me in metamorphic petrology, particularly that eclogites and Alpine geology could be so fascinating, and who taught me that thermodynamics was a powerful tool in understanding them. Ron Oxburgh showed me that fieldwork was an indispensable part of metamorphic petrology, particularly in making painstaking observations in structural geology. It was in Chicago, as a postdoc with that most superb of all experimental petrologists, Bob Newton, that I learned to trust in thermodynamic calculations after finding, by direct experiment, that they could be relied upon.

But, most important, I owe my biggest debt to Roger Powell, whom I met at a Geological Society meeting in London in the early 1980s and found that we shared a mutual enthusiasm for thermodynamics and petrology. Roger's abilities as a computer programmer are legendary, and I have learned more than I could acknowledge here from his skills. It has been a real pleasure to work with him over the years, and it is for these, and his role in them, that I am very pleased to accept this Bowen Award for 2009.

—Tim Holland, University of Cambridge, Cambridge, UK

Tim Holland and Roger Powell received the 2009 Norman L. Bowen Award at the 2009 AGU Fall Meeting, held 14–18 December in San Francisco, Calif. The award recognizes outstanding contributions to volcanology, geochemistry, or petrology.

Citation

Tim Holland and Roger Powell receive the 2009 AGU N. L. Bowen Award for an outstanding contribution to petrology and geochemistry—the result of an ongoing collaboration begun in the early 1980s—that has changed the way we carry out quantitative phase equilibria studies. A quantitative understanding of chemical reactions among minerals, fluids, and melts requires accurate representation of their thermodynamic properties, making a compilation of these properties one of the most important data sets in petrology and geochemistry. The Holland and Powell collaboration has produced the most complete data set of thermodynamic properties of end-members of the phases required to perform calculations on the conditions of formation of rocks and their interactions with fluids and melts. The data set is internally consistent, meaning that all of the available information has been appraised and combined statistically (in a least squares sense), yielding uncertainties and correlations. This allows uncertainties on the calculated results to be obtained—an important element of the Holland and Powell approach. However, quantitative phase equilibria studies require more than just a statistical optimization of the thermodynamic properties gleaned from various sources (experimental, calorimetric, etc.), and Holland and Powell have developed formulations for appropriate equations of state, thermodynamic models to treat nonideal mixing properties, ways to estimate thermodynamic properties, and improvements to some classic nonideal formulations to expand their domain of validity. For example, a critical contribution has been estimation of the mixing properties of complex phases such as the chlorites, the amphiboles, and Na-K dominated melts. In turn, this has enabled phase equilibria calculations to be made for a wide range of rock and domain compositions.

Although the responsibilities of Holland and Powell within their collaboration are clearly defined and complementary, the body of work recognized by this award would not have been possible without the collaboration. Their collaboration has produced 35 papers, of which 19 are authored by Holland and Powell or Powell and Holland. Six papers explain the basis for the internally consistent thermodynamic data set, describe methods to use the data set for various calculations, and provide software to enable users to undertake these calculations for particular rock and domain compositions. Additional papers describe the ever more sophisticated activity-composition models. Furthermore, a thermodynamic data set must evolve or its usefulness will diminish. Holland and Powell have been indefatigable over the past quarter century in increasing the number of entries in the data set, refining the quality of the data and the activity-composition models, and improving their software packages, as well as making it all available free via the World Wide Web.

Given the complex nature of phase equilibria calculations, the provision of “industry standard” programs—AX and THERMOCALC—was critical to enabling all of us to undertake these calculations with minimum training. AX is a program that takes mineral analyses and calculates the activities of the mineral end-members useful for thermodynamic computations. THERMOCALC is a thermodynamic calculation software package for addressing mineral equilibria problems that may be used to undertake a wide range of phase diagram calculations, including P–T projections; P–T, P–X, and T–X pseudosections; compatibility diagrams; and µ–µdiagrams. Phase diagram computations for defined bulk and domain compositions made possible by THERMOCALC have enabled researchers throughout the world to make advances in understanding the thermal evolution and the burial/exhumation history of orogenic belts.

The variety of applications of the Holland and Powell “tools” is beyond belief, and the work cited for this award has pervaded our community from low-temperature geochemistry to mineral deposits geology and from high-pressure metamorphic rocks to crustal melting. Please congratulate the 2009 Bowen awardees, Tim Holland and Roger Powell.

—Michael Brown, University of Maryland, College Park

Response

It is a pleasure and an honor to receive the 2009 AGU N. L. Bowen Award, jointly with my longtime friend and collaborator, Tim Holland. First, I would like to thank Mike Brown for the kind words in his citation, and also for his strong support of us and our work over many years now.

It is interesting to try and piece together how one comes to be what one is and do what one does. Of course, there have been many small influences as well as a few large ones. In addition to Tim, I would like to single out and thank Steve Richardson and Ian Carmichael, both mentors and exemplars as scientists and people. Steve was my Ph.D. supervisor at Oxford, and Ian was my boss in a year teaching at University of California, Berkeley in my first position out of Oxford. It was Steve who suggested I get involved with equilibrium thermodynamics, seeing that it was the way forward in metamorphic petrology, even though he knew little about how to go about it himself. I had little formal chemistry, but my voyage had started. I had no computer programming skills either, so I taught myself those too.

I would not be standing here were it not for Tim Holland. Neither of us would have dreamt at our first discussions at a meeting in London in the early 1980s that it would lead to such a long-standing, and certainly ongoing, collaboration. He has a great ability to see the big picture in what is needed for furthering understanding of rocks. His skill at bringing together and making consistent the huge volume of disparate thermodynamic data is difficult to comprehend. My peculiar interest has been in writing general software that therefore means that users can do what calculations they want. It is gratifying and humbling to realize that our work has had the impact that it has, and to see the way that it is used to throw light on geological processes. Thank you again for the Bowen Award.

—Roger Powell, University of Melbourne, Melbourne, Victoria, Australia

Richard W. Carlson received the Norman L. Bowen Award at the 2008 AGU Fall Meeting Honors Ceremony, held 17 December in San Francisco, Calif. The award recognizes outstanding contributions to volcanology, geochemistry, or petrology.

Citation

This year's recipient of the Norman L. Bowen Award is Richard W. Carlson, of the Carnegie Institution of Washington. Carlson’s scientific career was launched at University of California, San Diego, where he helped es-tablish the utility of the samarium-neodymium isotopic system by using it in three very important ways: lunar and meteoritic cosmochronology, mid-ocean ridge basalt heterogeneity, and the origin of flood basalts. Carl-son has since worked at the Department of Terrestrial Magnetism where he helped develop some of the petrologic uses of important isotopic systems such as 147Sm-143Nd, Pd-Ag, Re-Os, and 146Sm-142Nd.

Carlson deserves the Bowen Award because he has shown how to combine isotopes, trace elements, and planetary physics with petrology to address large-scale geochemical and cosmochemical problems. He has made important contributions in very different areas: early solar system cosmochronology, mantle geochemistry, magmas as tracers of mantle processes, Archean mantle lithospheric evolution, crustal evolution of the western United States, and isotopic techniques. Two of his most recent papers on the formation of early Earth reservoirs and dating of the oldest terrestrial rocks have had huge impacts on the field of geochemistry.

Carlson has shown strong professional leadership. He has run large, multiyear, multinational, multidisciplinary continental dynamics projects with huge seismological components. He has given significant public service to AGU and the Geochemical Society and has served as a most efficient and thorough editor at Earth and Planetary Science Letters. Above all, he has been an exceptional research staff colleague.

Modern petrology has become more diverse since Bowen's day and includes modeling, geodynamics and seismic imaging, trace elements, stable isotopes, and long- and short-lived radiogenic isotopes. Perhaps more than that of any recipient to date, Carlson’s research exemplifies this diversity.

—Steven B. Shirley, Carnegie Institution of Washington, Washington, D. C.

Response

Thank you for the kind words, Steve, and especially for the many years of enjoyable collaboration. I would like to thank those who nominated me, the Bowen Committee, the Volcanology, Geochemistry, and Petrology (VGP) section, and AGU for affording me this much appreciated honor. Scientific research is a pursuit that provides mostly private rewards through the thrill of discovery. In fact, at least in my experience, the more important the findings one produces, the more flack one receives from peers. But this is the aspect of Earth science that I find particularly appealing—that the problems we try to solve are fundamental, and hence complicated and not prone to revealing their solution easily, and certainly not without extensive debate and discussion with others working in the field. Receiving an award like the Bowen provides the great joy of knowing that the body of work done has made a positive impression on my esteemed colleagues in the VGP community.

Of course, my research is greatly aided by working at a place like the Carnegie Institution of Washington, where an enlightened administration only interferes when necessary, but otherwise provides the resources and support that give their staff an unfair advantage in the research arena. The Department of Terrestrial Magnetism (DTM) also is blessed with a great group of colleagues and a strong postdoctoral program. There is no question that I have benefited greatly from my association with the many creative and hardworking postdocs, students, and visiting scientists who have spent time in the DTM laboratories. I am particularly grateful to my wife, Sonia, with whom I share tales of the day’s events, and also benefit from her insight and expertise on the petrogenesis of the many funny named alkalic rock types that I’ve analyzed. I sincerely thank the VGP community for providing the scientific forum for my career, and for this award.

—Richard W. Carlson, Carnegie Institution of Washington, Washington, D.C.

Eiji Ohtani received the 2007 N. L. Bowen Award at the 2007 AGU Fall Meeting in San Francisco, Calif. The award recognizes outstanding contributions to volcanology, geochemistry, or petrology.

Citation

It is my pleasure to present Eiji Ohtani, one of the recipients of the N. L. Bowen Award of the American Geophysical Union.

Eiji Ohtani is indisputably the most prominent leader in the experimental studies of properties of Earth materials, particularly the melting relationships and the properties of melts under high pressures and temperatures. Eiji started his brilliant career in Mineo Kumazawa's lab at Nagoya University in the early 1970s. Mineo Kumazawa is one of the pioneers of large-volume high-pressure devices (others include Naoto Kawai and Syun-iti Akimoto), and Eiji played a major role as a young student in establishing new techniques of high-pressure and high-temperature experiments using a large-volume apparatus. His reputation was established already in the early 1980s based on his seminal papers on the melting of fayalite and forsterite under high pressures (to 20 gigapascals).

Soon after his Ph.D., Eiji moved to Australian National University (Ted Ringwood's lab) as a research fellow (I also applied for the research fellow position with Ted Ringwood, but Ted, of course, made the right decision as usual), and there Eiji established a multianvil lab from which a number of important results were found not only by Ohtani himself but also by Tetsuo Irifune and Takumi Kato. After coming back from ANU, Eiji built two high-pressure labs in Japan, first at Matsuyama (Ehime University) and next at Sendai (Tohoku University), and started an even more impressive and productive career. He has established an “army” of students and postdocs (his “army” is so big that I often wonder if it is “constitutional”) and has conducted a truly impressive series of experimental studies not only on melts and melting relationships but also on other related topics such as the stability of hydrous phases, kinetics of phase transformation, diffusion of ions under high pressures, etc. In fact, it is impossible to write a paper on melting or melts in the deep Earth without citing Eiji Ohtani's papers. Therefore Eiji's contributions fit very nicely with the description of the Bowen Award: a series of papers which, taken together, constitute “an outstanding contribution to volcanology, geochemistry and petrology.”

Eiji is full of energy, and I do not see any sign of him slowing down in his scientific activities. At the same time, he is a quiet and modest person. I am really pleased that AGU has recognized his fundamental contributions to volcanology, geochemistry, and petrology by awarding him the Bowen Award. Congratulations, Ohtani-san!

—Shun-Ichiro Karato, Yale University, New Haven, Conn.

Response

Thank you, Shun-Ichiro Karato, for your warm and generous citation. It is my great pleasure to receive the award that bears the name of Norman L. Bowen, who is the real pioneer and hero in Earth science.

As an undergraduate student at Tohoku University, I visited Hokkaido, Japan, in 1972 for a field survey of the Horoman ultramafic complex supervised by Ken-Ichiro Aoki, one of the pioneers in upper mantle petrology. I was so impressed by the beautiful and fresh peridotite outcrops, and I wanted to understand the mystery operating in the Earth’s deep interior. Since I was assured that high-pressure works are vital to clarifying the Earth’s deep interior, I decided to study at Mineo Kumazawa’s laboratory at Nagoya University as a graduate student. This is the reason I am now working as a professional in studying the Earth’s deep interior.

I struggled to develop a large volume press during the graduate course, and in 1979 I finally successfully made some experiments on melting of silicate minerals to 15 gigapascals. The experiments could be applied to a deep magma ocean, which was expected theoretically at that time by Wetherill, Hayashi, and Kaula in the primordial Earth.

I spent 2 years, 1983 and 1984, at the Australian National University as a research fellow in Ted Ringwood’s group. It was the most fruitful time in my research career, and I enjoyed research there by intensive discussions with young active postdocs, many of whom are now working as top runners in our science community. I spent plenty of time thinking about magma ocean issues and a possible crystal-melt density crossover, a current hot issue in geodynamics. I also enjoyed working with excellent technicians Alan Major and Bill Hibberson installing a large volume press.

In 1995, I spent 8 months at the Bayerisches Geoinstitute, University of Bayreuth. I was impressed by the friendly and active atmosphere of the institution, directed by Fritz Seifert and Dave Rubie. After my stay in Bayreuth, we continued to make intensive exchanges of young people and collaborations, such as study on shocked meteorites with Ahmed El Goresy, which was started by fruitful discussions with Tom Sharp during my stay in Bayreuth.

Finally, I would like to thank all of the excellent colleagues and brilliant students of my department at Tohoku University who made fruitful collaborations in my research career.

—Eiji Ohtani, Tohoku University, Sendai, Japan

Katharine Cashman received the N. L. Bowen Award at the 2006 AGU Fall Meeting. The award recognizes outstanding contributions to volcanology, geochemistry, or petrology.

Citation

It is a privilege and an honor to present the N. L. Bowen citation for Kathy Cashman. She is richly deserving of this recognition owing to her unique and original contributions to the field of volcanology. Kathy is best known for her quantitative characterization of volcanic rock textures using measurements of the size, size distribution, and shape of both bubbles and crystals. It is a real joy to sit next to Kathy and stare at a pile of SEM photographs of a volcanic rock, and then to watch her pull them apart crystal by crystal, spotting textural nuances that most of us would never have noticed, let alone had the temerity to interpret. As Ian Carmichael wrote in his nominating letter for Kathy, “It is with great chagrin that I realize that the textural features that I have observed but overlooked for long, can be used to reveal such important constraints on the cooling and ascent of magma.” A second area of Kathy’s research deals with basaltic lava flows, and how to employ their surface characteristics to infer the dynamics of their emplacement. In collaboration with Ross Griffiths, she has pursued a variety of laboratory-based fluid mechanics studies that have collectively led to a much better understanding of the factors that control lava flow emplacement, with major implications for volcanic hazards. Finally, Kathy’s research addresses degassing-induced crystallization of magmas as they ascend through conduits to the surface. She has shown how the interplay of gas loss and crystallization leads to a highly nonlinear eruptive behavior, with rapid transitions between effusive and explosive regimes. This is best demonstrated in her work on Mount St. Helens, which spans more than 25 years. Moreover, she has written up this research with a clarity and logic that is enviable. As Michael Manga put it in his nominating letter for Kathy, “She is one of a small number of people for whom I read everything they publish: The writing and reasoning are so clear that I always learn something.” Kathy’s academic success lies with three of her most characteristic traits: insatiable curiosity, artistic creativity, and considerable generosity of spirit. These have also made her an outstanding mentor to students at every stage of their careers. I speak for many in our profession when I say that Kathy Cashman is a most cherished friend and inspiring colleague.

—Rebecca Lange, University of Michigan, Ann Arbor

Response

I am humbled to receive an award that bears the name of Norman L. Bowen, whose legacy I have come to revere over the years. Acceptance speeches are, fundamentally, autobiographical and laden with thanks; mine is no exception, as I accept this award on behalf of the family, colleagues, students, and friends who have supported me through my career. I became a geologist at Middlebury College, thanks to the plate tectonics excitement of Peter Coney. After Middlebury, I worked in New Zealand and Antarctica, where I succumbed to the ‘red rock fever’ that plagues most volcanologists. My return to the United States brought me, circuitously, back to volcanoes in the guise of the public information scientist at Mount St. Helens, where I confirmed my passion for volcanology and decided, with the encouragement of senior U.S. Geological Survey scientists, to return to graduate school. At Johns Hopkins University, my advisors Bruce Marsh and John Ferry helped me to transform this passion into the knowledge and self-confidence needed to tackle scientific problems. My academic career started at Princeton University, where I initiated research themes that have sustained me through the years. Studies of submarine pumice with Dick Fiske (Smithsonian) and my first graduate student, Caroline Klug, and of basaltic tephra with Maggie Mangan (USGS), introduced me to the dynamics of explosive volcanism and the enchantment of Hawaiian lava flows, where my primary guide has been Jim Kauahikaua, a dear friend and gentle tutor. Lava flow distributaries have led me (1) to the North Atlantic and notorious ODP Leg 163, (2) to Canberra Australia, for experimental work with Ross Griffiths and Ross Kerr, (3) to Mount Etna, Italy, with Sonia Calvari and Harry Pinkerton, and (4) back home to the Cascades, where my students and I have abandoned rock hammers for the shovels required to explore the myriad products of explosive volcanism. From a broader perspective, I see that turning points in my career have arisen primarily through serendipity: Jon Blundy’s (Bristol) visit to Oregon in 1998; a single e-mail from Mauro Rosi (Pisa) in 2001. I am grateful to both of them for sharing their scientific work and their friendship, as well as to my students, my UO colleagues Michael Manga and Paul Wallace, and my department head Dana Johnston. Last but not least, I’d like to thank my extended family, in which I include Becky Lange, who have provided unconditional support for all my endeavors.

—Katharine Cashman, University of Oregon, Eugene

Roberta Rudnick received the N. L. Bowen Award at the 2006 AGU Fall Meeting. The award recognizes outstanding contributions to volcanology, geochemistry, or petrology.

Citation

One sign of a great scientist is that he or she uses fundamental observations in nature or experiments to drive questions and hypotheses on how natural processes work. Roberta satisfies all of these criteria, and more.

Working as a graduate student with Roberta, I came away with a deep appreciation for the value of having data. One example of this philosophy was Roberta’s seminal paper on the average composition of the continental crust, which has stood the test of time. But coming up with an estimate of the composition of a reservoir was really just a step in Roberta’s grander goals of answering the question of how the continents formed. The problem is that this question is too vague to mean anything to the noninitiated, and to the experts, the question is ill-posed because continent formation is so complicated that there seems to be no simple answer. It is in these circumstances where Roberta shines the most.

Roberta has the uncanny ability to see the big picture by synthesizing and distilling seemingly disparate details into a well-organized and clear message. A good example of this is Roberta’s 1995 paper “Making continental crust.” Although this was a review paper, Roberta formulated some of the most important questions or controversies in the field in a concise manner. Most review papers are just summaries of current paradigms, and after 10 years, they stop being cited or are replaced by new review papers. Roberta’s paper, however, continues to be cited, a reflection that much research right now is still driven by the questions that Roberta so elegantly laid out.

Finally, an enviable characteristic of Roberta is that she’s always exploring various tools to answer her questions. She appreciates the need to be interdisciplinary: Witness her various papers with geophysicists on the thermal state of continents and deep lithospheric evolution. She also systematically explores new techniques and new isotopic systems, as exemplified by her contributions to laser ablation ICP-MS, osmium isotopes, and now lithium isotopes, all to address specific issues on continent formation and dynamics. There is thus no doubt that Roberta is one of our great leaders and communicators in the field of geochemistry.

I will end my citation on a more personal note. When I came as a student to work with Roberta, even though I thought I knew a lot, I didn’t really know how to do science. By simply being her apprentice, I learned from Roberta how to be a scientist. Roberta has been and continues to be an inspiration and role model to so many of us. It is thus fitting that she is one of this year’s recipients of the N. L. Bowen Award.

—Cin-Ty A. Lee, Rice University, Houston, Texas

Response

Thank you, Cin-Ty. I am honored and thrilled to have been selected for the N. L. Bowen Award.

Like others, my interest in geology stemmed from an excellent class, this one in high school, which led me to pursue a geology degree at Portland State University. There I met Bill McDonough, and together we pursued master’s degrees with Denny Nelson at Sul Ross State University. The award of a U.S. National Science Foundation graduate fellowship literally opened the world to me, so Bill and I headed Down Under for Ph.D. study.

Our years at the Australian National University were truly golden. With excellent colleagues, unsurpassed analytical equipment, and a cadre of fellow graduate students who were doing exciting research (and really knew how to party) we learned what research science was all about. Ross Taylor, my Ph.D. supervisor, had worked with Scott McLennan on the composition of the upper continental crust and published a model for the crust composition in their famous 1985 book. After solving the upper crust, Ross recognized the uncertainties in the lower crust composition and suggested I work there. So that’s what I did, and have been working on this topic, and the implications of the crust composition for Earth dynamics, ever since.

Following ANU we spent 2 years in Mainz, Germany, with Al Hofmann and his group at the Max Planck Institute. Working closely with Steve Goldstein, I delved into Pb isotopes, and we discovered that the lower crust is not as unradiogenic as supposed, with implications for the Pb paradox, which is still not solved so many years later.

Returning to ANU for a 5-year research fellowship with Ted Ringwood, my research focus moved a little deeper, into the upper mantle. My ANU days culminated in a paper on the composition of the lower crust, with David Fountain, and a new model for the crust’s composition. However, the most important collaboration I had while at ANU was with Bill: the arrival of our son, Patrick, who has been a joy in our lives and keeps us balanced (at least a little).

My time at Harvard, and my move to Maryland in 2000, have also been productive and exciting years. Highlights include mentoring great students (Cin-Ty Lee, Matthias Barth, and Fanzhen Teng) and developing a close collaboration with Gao Shan (Chinese University of Geosciences, Wuhan), with whom I’ve been discovering the extraordinary history of the North China craton. I owe a debt to our chair, Mike Brown, for his vision for our department and who has built an internationally recognized (and very collegial) geochemistry group, putting Maryland on the map.

Finally, Bill McDonough has been my soul mate, cheerleader, mentor, and geochemical sparring partner for more than half my life. My journey has not been alone and would have been very different if our paths had not crossed so many years ago.

—Roberta Rudnick, University of Maryland at College Park

Paul Renne received the N.L. Bowen Award on 6 December 2005 from the Volcanology, Geochemistry, and Petrology Section at the 2005 AGU Fall Meeting in San Francisco, Calif. The award recognizes outstanding contributions to volcanology, geochemistry, or petrology.

Citation

It is a great pleasure to offer this citation of my good friend Paul Renne. I want to describe Paul’s rigorous and thoughtful approach to science, as illustrated in a remarkable series of papers that simultaneously drove developments in argon (Ar) geochronology and contributed to a fascinating scientific problem.

One of Paul’s enduring interests is flood basalts. How do these massive eruptions originate? Do they result solely from rifting, or are the heads of mantle plumes involved? Do flood basalts coincide with mass extinctions, and if so, can causality be proved or disproved? How can geochronology help answer such questions?

Prior to Paul’s work, the Siberian Traps were thought to have erupted over millions of years, sometime near the Permian-Triassic extinctions. In 1991, Paul reported 40Ar/39Ar ages refuting this view: A key sequence of Trap lavas erupted with very high effusion rates, as expected for a mantle plume origin. Determination of accurate rates requires high-precision analyses. And his results speak for themselves in terms of precision: They are extraordinary, attesting to the analytical skill developed at the Berkeley Geochronology Center.

To establish a relationship between flood basalts and mass extinctions requires accuracy as well, for example, to compare an Ar age of a trap flow with zircon ages of ash beds near the extinction boundary. But Ar ages suffer from complications that can cause inaccuracy, and in his work on the Permian-Triassic boundary one senses Paul’s frustration with this limitation.

In the short term, he found a way to sidestep this issue, by Ar-dating bentonites bracketing the boundary. These ages show, that to within a few hundred thousand years of uncertainty, the eruption and the extinctions were coincident, permitting causality. In the longer term, Paul sought to identify and reduce systematic error in 40Ar/39Ar ages. Through compilation of numerous age standard analyses, he effectively eliminated intercalibration as an error source. From his rigorous error propagation formulae, Paul identified another critical source of systematic error: the 40K (potassium-40) decay constant. For several years he has worked to find natural samples of independently known age from which the decay constant can be deduced. This quest continues and is now having an impact in uranium/lead geochronology as well, as the debate over uncertainty spreads to other methods.

For his contributions to Ar geochronology and to our understanding of flood basalts, and for contributions to hominid evolution studies I have not mentioned, Paul Renne richly deserves this award.

—K. A. Farley, California Institute of Technology, Pasadena

Response

I am especially gratified to receive this citation from Ken Farley, one of the truly outstanding Earth scientists of my generation. I am humbled to share this recognition with the great scientists who have previously won the N.L. Bowen Award, many of whom have influenced me deeply over the years.

I am honored to be associated in some way with Norman L. Bowen. I learned about Bowen’s work from my first geology teacher, at Lassen College, in Susanville, Calif. Probably none here tonight have ever heard of Martin S. Peterson, but he was an extraordinary teacher who first kindled my interest in geology.

I had many important mentors as a student—both undergraduate and graduate—at the University of California, Berkeley, including George Brimhall, Ian Carmichael, Garniss Curtis, Dick Hay, Hal Helgeson, and Rudy Wenk. I am fortunate to continue my association with some of these mentors as current colleagues, along with others such as Don DePaolo and Mark Richards, who came to Berkeley after I finished my Ph.D.

Among the Berkeley faculty who nurtured my scientific and professional growth, Ian Carmichael was particularly influential. Along with his scientific mentorship, Ian introduced me to my wife, Brooke, who has enriched my life in many ways and who herself deserves thanks for helping to enable my career.

As a postdoc at Princeton University, N.J., I learned 40Ar/39Ar geochronology from Tullis Onstott, before he became a geomicrobiologist. At Princeton, I was exposed to some exciting ideas about the origins and consequences of flood basalts by Jason Morgan. Unfortunately, the importance of Jason’s ideas eluded me at the time. After all, coming from Berkeley I knew what caused mass extinctions. It was not until several years later, when Asish Basu introduced me to the Siberian Traps, that I really got involved in this topic.

Despite working in Garniss Curtis’s K-Ar lab as a Ph.D. student, during a time in which some exciting work in dating hominids was being done right under my nose, I was largely oblivious to the topic until I returned to Berkeley in 1990. Subsequently I have been fortunate to collaborate extensively with the great paleoanthropologist Tim White in refining the picture of hominid evolution over the past six million years.

I must acknowledge the extraordinary support of my colleagues at the Berkeley Geochronology Center: Tim Becker, Alan Deino, Abed Jaouni, Ken Ludwig, Roland Mundil, Warren Sharp, and Lisa Smeenk. I also thank the Ann and Gordon Getty Foundation and the U.S. National Science Foundation for their support.

—Paul Renne, Berkeley Geochronology Center, Calif.

Peter B. Kelemen received the Bowen Award, presented by the Volcanology, Geochemistry, and Petrology Section at the 2004 Fall Meeting in San Francisco, California, last December.

Citation

Tonight we are here to honor Peter Kelemen, a leader in our field. Peter has led by the single-minded pursuit of a big idea: Virtually everything in VGP is pertinent to or can be explained by reactions between migrating magma and the rocks through which they pass.

I wondered some time ago from where this passion derived. It seems that as a young man, Peter, like many young searchers, went to India and pondered the meaning of life, in Peter's case while doing geological fieldwork. The vision struck while Peter was sitting on an outcrop of mantle peridotite in the Himalayas. There were all these rocks, tens of kilometers thick, with dikes passing through them. How could the magma possibly traverse such long distances without being fundamentally modified by the materials through which they pass? And how could they then not leave a record of their passage?

Armed with this vision, Peter headed to graduate school. Since that time, Peter has investigated melt-rock interaction with amazing breadth and depth, through a combination of careful fieldwork, quantitative chemical modeling, and investigation of the fluid dynamic instabilities associated with migrating magma. He showed us that the ubiquitous "dunite channels" in exposed peridotites were the remnant tracks of migrating magma. This recognition has led to a wide range of subsequent developments in fields that include ophiolite field studies, the fluid dynamics of melt migration, the chemical consequences of melt migration, and U-series disequilibria.

To investigate these problems, Peter was also walking over the ocean crust, and he decided to turn his attention to the physical aspects of its origin by carefully looking at the structures and chemical compositions of the gabbroic layers. This work led to papers that definitively laid to rest competing models for the physical construction of the ocean crust. Through his highly interactive style, Peter has developed far beyond melt-rock interaction. He has related seismic velocity to chemical compositions and identified the physical aspects of delamination of continental lithosphere. He has emerged as a leader of large field programs on land and at sea.

One of the favorite phrases I remember from graduate school is Gil Hanson's comment that "there are no bad problems, only bad scientists." Peter exemplifies the positive aspects of this perspective. It was not necessarily that his vision of mantle-melt interaction was prescient. But Peter pursued this problem with such vigor that he has in many ways redefined our field. It led him to write papers in geophysics, geochemistry, fluid mechanics, seismology, and tectonics, to lead ambitious field programs, to do experiments, and to direct theses in theoretical geodynamics. Out of all these interactions has come a host of scientific advances, new problems to explore beyond melt/rock interaction, and the need for all of us when interpreting our data to consider the consequences of the inevitable reactions that take place during transport.

Friends and colleagues, please welcome Peter Kelemen, a scientist who has redefined the way we think, and one of the most productive and influential contributors to our field in the past five years.

—Charlie Langmuir, Harvard University, Cambridge, Mass.

Response

As a graduate student, I imagined that I was engaged in a scientific discussion with Norman Bowen, so it feels like the pinnacle of success to be associated with Bowen in this way.

I have a habit of seeking out father figures such as Bowen. I have an excellent real father, who is here tonight. A refugee from both Hungarian Nazis and Communists, but a lover of European culture, my father taught me by example never to join any political groups, but to appreciate what the world has to offer.

In 1980, mapping in the Himalaya, I saw felsic intrusions cutting peridotite. I was inspired with a vision: Reaction between felsic magmas and the mantle would solve the "andesite problem" posed by Bowen and Fenner! I didn't realize that if there still was an andesite problem in 1980, it was that there were too many solutions.

Bernard Evans is The Expert on peridotite metamorphism, so I went to Seattle. There I found many father figures, including Mark Ghiorso and Stu McCallum as well as Bernard. At the University of Washington, I could develop my "andesite inspiration" without confronting other hypotheses directly. When I emerged, I had something of my own.

Also in 1980, I joined a company specializing in "extreme terrain mineral exploration." My longstanding business partner, Geoff Radford, lived simply to do every job right. If he said yes to something, he was totally committed. I have tried to emulate this.

For brevity, I am now going to thank people in clumps. Including Geoff Radford, the first is the tough clump. Always honest, Peter Molnar and Dan McKenzie were not formal mentors, but have been simultaneously exemplary, terrifying, and encouraging. I once told Dan that I thought most scientists don't live up to their potential. Dan replied, "Not you! You're an overachiever!" Nobu Shimizu belongs here, with Charlie Langmuir. Adolphe Nicolas, who exemplifies the application of field geology to geodynamics, is a fierce but generous critic of my work.

Foremost among the supportive clump are Stan Hart and Mike Purdy. Steve Holbrook, Jack Whitehead, Marc Parmentier, Marc Spiegelman, Einat Aharonov, Jun Korenaga, Mike Braun, and Matthew Jull are geophysicists who patiently helped me. Geochemist Ken Sims overlooks my ignorance of what an activity ratio really is. Gene Yogodzinski pretends to forget that I have never actually been to the Aleutians. And Henry Dick—Tough? Supportive? Fratricidal? We are all siblings in Henry's dysfunctional family.

Last but not least, I thank Greg Hirth. We've done the best of projects together, deploying the Giant Tripod and BOLO, the Blimp for Onland Oceanography. Greg is neither intimidating nor intimidated. He follows his famous father's footsteps, but doesn't feel overshadowed. There's virtue in exploring new worlds, even if they are thickly inhabited and new only to us. Today Greg and I presented work on earthquakes. Neither of us is burdened with an extensive knowledge of this topic, and there are many specialists. But it's new to us, and perhaps we will find something that is new to them.

—Peter Kelemen, Woods Hole Oceanographic Institution, Woods Hole, Mass.

John W. Valley received the Bowen Award, presented by the Volcanology, Geochemistry, and Petrology Section at the 2003 Fall Meeting in San Francisco, California, last December.

Citation

“Jim O’Neil and I are particularly pleased to present Professor John Valley, of the University of Wisconsin, for this year’s Bowen Award. We have known John for about 25 years, first as a graduate student, and now as colleague and good friend. We nominated him in recognition of his recent work on zircons from early Archean rocks of northwestern Australia, which provides documentation of previously missing Earth history with evidence for an early ocean and a relatively cool history during the Hadean Eon. John has also published a major review on oxygen isotope variations of magmatic zircons preserved through geologic time, as a result of which he proclaims that ‘zircons are forever.’

“John’s research interests are exceedingly broad, although most involve stable isotope measurements of materials involved in diverse Earth and planetary processes. In the last 5 years, he has authored or co-authored papers on a wide variety of topics, such as the early Archean history of the Earth, Martian meteorites and their association with possible life forms, sedimentary basin flow regimes, geochemistry of ocean island and continental volcanic rocks, mammalian paleodiets, characterization of biogenic magnetite, and authigenic and diagenetic minerals, and has conducted ongoing projects focused on his longstanding interests related to fluid flow. John published a major review paper on the use of the ion microprobe to obtain stable isotope ratios of natural materials, and he edited and contributed to several books on stable isotope geochemistry that are widely cited and consulted. His work continues to draw a great deal of attention both here and abroad. His productivity has continued unabated despite his many administrative obligations in professional service to the University of Wisconsin, as well as to many national and international organizations.

“Professors Don DePaolo of the University of California, Berkeley, Colin Graham from the University of Edinburgh, and Ed Stolper of CalTech provided glowing letters of recommendation on John’s behalf. It is evident from these recommendations and John’s vita that he is a highly active and cooperative scientist in geochemistry, petrology, and related fields. He maintains ongoing collaborations in a wide variety of fields with scientists from many institutions, both in this country and abroad. John has proven to be one of the most successful of the many academic scientists who obtained their Ph.D. degrees from our department.

“John has been a highly influential colleague both in the United States and internationally. He has initiated and maintained valuable connections with professors at the University of Edinburgh and at CalTech, and these collaborations have led to major research initiatives, some of which are ongoing. He has developed a large and lively research program with many postdoctoral fellows and visiting professors as well as a continuing cadre of enthusiastic graduate students. Most of his former Ph.D. students and postdoctoral fellows are now tenured professors, which only adds to his stature. Considering the outstanding quality of the nominee’s research, the quality of the papers for which he is cited, and his productivity, he meets the criteria of the recipient of this award exceedingly well. With the highest praise, we present to you the Bowen Award winner of 2003, John W. Valley.

—Eric Essene and Jim O’Neil

Response

“It is a great honor to receive the N.L. Bowen Award from AGU. It’s a pleasure for it to be presented by Eric Essene and Jim O’Neil, who have been good friends for 25 years and have both greatly influenced my career. The Bowen Award is very special because of the distinguished past recipients and because of its namesake.

“It’s appropriate to say something about Bowen on this occasion. As a dedicated magmatist, he only forayed into metamorphism a couple of times, but it was typically brilliant. I especially enjoy his terse summary of metamorphism in marble, ‘Tremble, for dire peril walks. Monstrous acrimony’s spurning mercy’s laws.’ We all know at least the first five index minerals (tremolite, forsterite, diopside, wollastonite, periclase), but fewer of us realize that, written in 1938, this phrase was also a political warning against appeasing Hitler. I think this illustrates that even the specialist Bowen was aware of what we might now call ‘broader impacts.’ We should not lose track of what’s going on around us.

“I want to mention some of the people who’ have helped me to be here tonight. There are many more. My parents first exposed me to geology and the outdoors. At age 6, they gave me a shiny new rock hammer. This was quite a lethal instrument for one so young. They instructed me, ‘don’t stick the pointy part into your forehead,’ and we visited gem pegmatites in Maine and hiked the White Mountains of New Hampshire. This influenced me to go to Dartmouth, where I was fortunate to study with Dick Stoiber and to spend a month with him in Guatemala.

“I went to Michigan for graduate school still thinking about andesite volcanoes. But Eric Essene convinced me that rocks are more interesting if they don’t melt. Eric had a great group of students. He gave us equal doses of hard work and fun, of metamorphic petrology, mineralogy, and critical thought. My M.S. was petrologic. I looked for regional patterns in fluid compositions from Adirondack marbles. Of course, we know now, there aren’t any regional patterns. Fluids, when they exist in granulites, are localized. Again, I was influenced by Bowen who said, ‘to many petrologists, a volatile component is exactly like a Maxwell demon; it does just what one may wish it to do.’I took his sarcasm as a challenge to set quantitative limits on the role of metamorphic fluids and how they interact with rocks.

“John Bowman showed me that stable isotopes are a powerful tool for studying fluids, and he introduced me to Jim O’Neil, who was then at the U.S. Geological Survey in Menlo Park. With Eric’s blessing, I redirected my Ph.D. to include stable isotopes. There was no isotope geochemistry at Michigan in those days, so this entailed many enjoyable trips across the country.

“My experiences with Jim are what finally shaped me as a geochemist. He generously shared his knowledge and his lab. The isotope world was smaller then. Jim felt the pulse of the science. He knew everyone, what they did, and what were important problems. Jim also had great equipment. At night, I could run the silicate extraction line and two mass spectrometers simultaneously. This is something I tell my students never to do.

“My first job was at Rice. In 1982, Dieter Heymann, Rob Dunbar, and I wrote a proposal to buy an ion probe. I was tired of hand picking minerals. It’s probably a good thing we weren’t funded because we had no idea what we were getting into. No one did. The multi-collector instrument we actually needed wasn’t built until 15 years later. Rice was good to me, but Andrée and I jumped for the chance to live in glaciated Wisconsin on the edge of the shield.

“We moved to Madison with four Rice students. These and others have been the most satisfying part of my career. Will Lamb demonstrated fluid absence in granulite facies metamorphism in the Adirondacks; Jean Morrison proved that the Marcy anorthosite massif intruded as a high δ18O magma; and Claudia Mora worked out the complexity of metamorphic brines at Boehl’s Butte. Later, Steve Dunn demonstrated polymetamorphism at the Tudor gabbro, and Doug Crowe made the first laser probe analyses of sulfur isotope ratio. Jim O’Neil suggested using a laser for oxygen isotope analyses of silicate minerals in 1985. A lot of people have made good use of our laser system since then, including Matt Kohn, Ilya Bindeman, Liz King, and Jade Star Lackey.

“In 1989, I went to Edinburgh on a Fulbright to try out their new Cameca 4f ion microprobe. This technique offered the promise of in situ analysis for sample sizes one million times smaller than by laser, but no one knew if it would ever be accurate enough for terrestrial studies. I set a goal of 1 per mil for precision. Colin Graham, John Craven, and I worked the whole year on oxygen isotopes. We had a spectacular, unbroken record of failures. It was like lightning. We never got the same number twice, even on standards. I won’t bore you with the reasons, but I learned that ion probes are hard! Finally, in my last week we broke the 1 per mil barrier; we drank champagne and planned for the future.

“John Eiler and I have been back to Edinburgh many times, and our collaborations with Colin and John have included the most fun science of my life. Later, William Peck accompanied me to Edinburgh with Jack Hills zircons, including the one that Simon Wilde dated for us at 4.4 Ga. This was part of a larger study. We were analyzing zircons of all ages to investigate maturation of the crust. I had assured William with all my full professorial authority that any zircon from an igneous rock from so early in the Earth’s history would be primitive in oxygen isotope ratio. Of course, that’s not what we found, and the simplest interpretations led to quite an interesting hypothesis as Eric has mentioned. Now we are buying an ion probe in Madison and we are going to test our model.

“I want to close by thanking my wife, Andrée, who is here tonight. She helped on many projects. Throughout, she has given me the encouragement and freedom to work on rocks, whenever I wanted. That’s been very important.

“Thank you all. It’s been great fun, and it keeps getting better.”

—John W. Valley, University of Wisconsin, Madison

William I. Rose received the Bowen Award, presented by the Volcanology, Geochemistry, and Petrology Section at the 2002 Fall Meeting in San Francisco, California, last December.

Citation

“I am happy to be able to introduce Bill for this well-deserved honor. I’d first like to thank Bill’s colleagues who wrote him such strong letters of support: Fred Anderson (University of Chicago, the winner of last year’s Bowen Award); Steve Sparks (University of Bristol, Great Britain); Fred Prata (Commonwealth Scientific and Industrial Research Organization, Australia);Tom Casadeval (U.S. Geological Survey); Jon Fink (Arizona State University); and Hugo Delgado (National University of Mexico).

“I would like to summarize Bill’s many accomplishments, in research, collaborative efforts, and student outreach. His earliest professional work extended his graduate studies in gas and ash emission studies in Central America, and expanded to Indonesia, Washington, Hawaii, and Antarctica. In the 1980s, he began developing an interest in the potential aircraft hazards from volcanic clouds, years ahead of any serious scientific efforts towards this issue. Bill was one of the first in volcanology to embrace satellite data to study volcanic emissions and is a well-recognized leader in the field.

“With more than 150 published papers on volcanic studies, Bill has investigated multispecies and regional gas measurements of volcanic emissions, ash/aerosol interactions, aircraft hazards, distal ash fallout patterns, quantitative retrievals of ash particles, and detection of ice in volcanic clouds. He developed the first methodology to use infrared satellite data for quantitative retrievals of ash particles, size, and cloud mass: his ground-breaking work with his graduate student Shimeng Wen in 1994 formed the basis for current methods of infrared retrieval of ash particles.

“His past 5 years of accomplishments include his leadership toward merging multi-sensor retrievals of volcanic clouds, deriving simultaneous data of ash, aerosol, and gas species. He has led efforts to develop new monitoring, and analytical tools with a variety of sensors, and has published valuable syntheses of remote sensing studies. These retrievals have produced improved understanding of volcanic cloud/ atmosphere interactions, quantitative measures of volcanic cloud compositions and evolution, and advancement of a wide variety of remote sensing tools for volcanologists.

“His ties to Central America are perhaps the strongest of any U.S. volcanologist. Since his graduate work in the late 1960s, he has made annual trips to Central America, particularly Guatemala, and has published over 50 papers on Central American volcanology. For the past 3 years, he has led collaborative field excursions to Guatemala and El Salvador. In 1999, he graduated a master’s student, Carlos Pullinger, from El Salvador, who is now a leader in El Salvador’s natural hazards mitigation program. He brought one of Guatemala’s leading volcanologists to Michigan Tech this past year, Oto Matías, to complete his bachelor’s degree in geology. This fall, he hosted Dr. Hugo Delgado (Mexico) and Dr. Jose Viramonte (Argentina) as Visiting Scholars.

“Bill served as department head at Michigan Tech from 1990 to 1998. He led the development of Michigan Tech’s Remote Sensing Institute in 1998, spanning eight departments and over 40 researchers on campus, twice serving as director. He initiated a Remote Sensing Minor program for undergraduates as a means to attract diverse students to the field of remote sensing. Through an NSF International Travel Grant, he led a dozen international and American graduate students for 2 weeks to the IAVCEI Bali meeting in 2000, via Hawaii and Pinatubo.

“In 2001, Bill organized and hosted the Volcanic Clouds Workshop at Michigan Tech, attracting nearly 50 researchers from 11 countries, six of the nine Volcanic Ash Advisory Centers (VAACs), nine universities, and several government meteorological and volcanological organizations. Sponsorships from NASA and NSF secured by Bill helped support the meeting, and particularly the 17 student attendees. He is organizing the second meeting for summer 2003.

“In summary, Bill has made significant contributions to the field in research, in service, and in education. He has trained and mentored dozens of students, and has made many contributions to the growth of volcanological sciences, hosting field trips and workshops and developing funding opportunities targeted specifically for students. His work in geosciences has been abundant and far-reaching, and he is a clear leader in volcanology and remote sensing. His leadership skills together with his enthusiasm have brought together diverse groups of scientists and operational workers for the betterment of volcanology. Bill Rose is a very deserving recipient of this year’s Bowen Award.”

—Gregg Bluth, Michigan Technological University, Houghton

Response

“Thanks to Gregg Bluth and Fred Anderson for the introduction, and to Becky Lange and the Bowen Award Committee. The Bowen Award is a great honor, but it seems an extravagance given that my work is great fun, takes me to the world’s beautiful places repeatedly, and allows me to work with optimistic, smart, and talented young people. The Bowen Award truly shines brighter than many other awards, especially in my case. One award I got earlier was called the ‘Peter Principle Disorganization Award’ from a group called the Association of Derelicts and Slovenly Slobs, which I later found out included Jim Vallance, Deb Schueller, and Jim Paces. This is way better!

“I want to mention some of the many people I have met in and around volcanoes who have inspired me. In 1966, Dick Stoiber saw me at Dartmouth and asked what I’d do after graduation, 6 weeks away. I knew I didn’t want to visit Vietnam. Dick said I could work climbing seven Central American volcanoes. He gave me books and a student deferment. Dick was a dauntless man who had such passion that you had to work hard for him. He explored all the possibilities of being a senior professor. Other inspiring professors, Bob Decker and Bob Reynolds, and fellow students Al Eggers, Mike Carr, and Paul Taylor were significant.

“Next I moved to Houghton, a hard-rock town, where my family was happy and where I have creative colleagues and students. Michigan Tech tries to be a place where engineers are respected and valued. One result of the elevation of engineers is that non-engineers bond. Disciplinary boundaries are low. Engineers have wonderful equipment in clean, well-organized labs that are underutilized and can be borrowed by scientists with strange applications. My colleagues at Michigan Tech now include Gregg Bluth, Matt Watson, Alex Kostinski, Jimmy Diehl, Rich Honrath, Raymond Shaw, and Will Cantrell.

“I worked in Central America since Dartmouth days. In 1973–1975, Sam Bonis made huge collections of ashes from Fuego, and with these I worked with Fred Anderson and Steve Self. I learned Fred’s thoughts about gases, subduction zones, and melt inclusions, and worked with Laurel Woodruff. In 1978, I went to NCAR to learn about the atmosphere. Working under Paul Crutzen and Dick Cadle and with Bill Zinzer, we did a series of volcano aircraft samplings. I met Raymond Chuan, Bill Zoller, and Barry Huebert.

“The 1980s were great! Mount St. Helens in 1980–1982 amounted to the best learning experience of my life. We had meetings with 30 to 80 scientists daily discussing real-time data. I met Rick Hoblitt, Don Swanson, Kathy Cashman, and many more. In January 1983, led by Servando de la Cruz-Reyna, I went with Bill Zoller and Tom Casadevall into the newly-formed, H2S-rich crater of El Chichon. Then to Toba Caldera with Craig Chesner and George Walker and to Erebus and White Island with Phillip Kyle. Next it was Merapi and Augustine with Bob Symonds, and Costa Rica and Chile with Bob Andres. Kilauea began its current eruption in 1983, and I learned from Paul Greenland and Torrie Chartier, whose work at HVO was followed by a successful career as head of an all-woman diamond exploration company and a bio in Worth Magazine.

“In the late 1980s, I got into satellite-based remote sensing. Steve Self, Lori Glaze, and Rick Holasek helped—at first we knew almost nothing! Grant Heiken and others at Los Alamos triggered an aircraft mission to Augustine volcano, and I got lots of data from Gary Hufford. Shiming Wen made it possible for me to begin to understand radiative transfer. Dave Schneider really loved remote sensing from the beginning and always had snacks handy. The NASA EOS volcanology team headed by Pete Mouginis-Mark allowed a great expansion of colleagues who shared an interest in remote sensing: Peter Francis, Joy Crisp, Andy Harris, Arlin Krueger, Fred Prata, Vince Realmuto, Howard Zebker, and Luke Flynn. It lasted 12 years, and this networking supported an army of students. This triggered a great interdisciplinary experiment in a shared remote sensing lab where a diversity of students Dave Schneider, Judy Budd, Drew Pilant, and Mike Dolan worked together and truly taught each other.

“I undertook an administrative career as department chair. I used Stoiber’s lessons here: spend all the money ASAP and ask for more; hire new people as often as possible; keep a lot of balls in the air and they’ll be confused, etc. I conclude that no one should do that job for too long. Then I spent a rejuvenating year-long leave at Bristol, which has become the world’s leading volcanology program. Steve Sparks is a great leader, and he put me in an office with Oleg Melnik, Oded Navon, Eliza Calder, and Anne Marie Lejeune. I visited Montserrat and the Bristol field class in Santorini and worked with Gerald Ernst. I also met Clive Oppenheimer, Hans Graf, and Christiane Textor.

“Most recently, I have facilitated increased work in El Salvador and Guatemala and local colleagues in those countries including Carlos Pullinger and Otoniel Matías. We have done workshops on remote sensing of volcanic clouds and eruptions, where I met George Stephens, Andrew Tupper, Rene Servrandrx, Jose Viramonte, and many more.

“It is time to shut up, but I also mention my family—Nanno, Chris, and Jason, who put up with a lot of absences during my many great field trips and loved me anyway. And I thank again my many students that I haven’t mentioned yet, but haven’t forgotten—Mike Conway, Gari Mayberry, Bill Capaul, Dave Delene, Sid Halsor, Tony Longo, Paula Peterson, Colleen Riley, Greg Hahn, Gordon Keating, Gerardo Carrasco, Glen Johns, Barry Green, John Graf, Emily Constantine, Roger Barlow, Darrell Sofield, Dennis Martin, Paul Kimberly, Tianxu Yu, and John Drexler. Students have always taught me more than I have taught them. Rick Wunderman stands out as the student who taught me most, especially that the journey is more important than the destination. Thanks again, and cheers to all.”

—William I. Rose, Michigan Technological University, Houghton

Alfred T. Anderson, Jr. received the Bowen Award, presented by the Volcanology, Geochemistry, and Petrology Section at the 2001 Fall Meeting in San Francisco, California, last December.

Citation

"I have the honor and great pleasure of giving the citation for the 2001 Bowen Award to Alfred T. Anderson, Jr. Fred Anderson receives this year's award for pioneering the use of silicate melt inclusions in phenocrysts of volcanic rocks to determine preeruptive volatile concentrations in magmas and for applying melt inclusion analysis to fundamental problems in volcanology, geochemistry, and petrology. A melt inclusion, typically less than 100 microns across, is a glass droplet completely surrounded by its host crystal, which Fred has successfully argued acts as a pressure vessel, preventing degassing of the trapped melt. Knowledge of the volatile content of magmas, mainly water, carbon dioxide, sulfur species, and chlorine, is fundamental to understanding the dynamics of magmas, mechanisms of explosive volcanic eruptions, gas emissions from active volcanoes, volcanic additions to the atmosphere, and magmatic contributions to hydrothermal ore deposits. Because magmas degas as they ascend and erupt, or crystallize at depth, direct knowledge of preeruptive volatile contents long eluded petrologists faced with extracting this information from either rock samples or analyses of volcanic gases.

"Fred's first paper on dissolved volatiles in melt inclusions was published nearly 30 years ago. There followed several more papers in the early 1970s. In those days, Fred was nearly alone in advocating the importance of measuring dissolved volatile concentrations in melt inclusion glasses. Fred and his student David Harris developed equipment for quantitative extraction and analysis of the gas trapped in single melt inclusions. Published in 1984, their results were the first direct measurements of the preeruptive water and CO2 contents of basaltic and andesitic magmas. A more precise method became available in the early 1980s at Caltech with the use of Fourier transform infrared spectroscopy (FTIR) to determine water and CO2 dissolved in silicate glass. Fred recognized the value of the FTIR method and, with student Chris Skirius, analyzed melt inclusions in quartz phenocrysts from the rhyolitic Bishop Tuff, demonstrating the power of analysis of melt inclusions from stratigraphically controlled samples and sparking a revolution in melt inclusion studies of volcanic rocks. The analytical method perfected by Fred and associates is the industry standard today. Fred's leadership, however, goes well beyond application of an existing tool to an important problem. His general papers on melt inclusions include how to tease data from seemingly intractable samples by rehomogenizing partially crystalline inclusions, diffusive equilibration of inclusions with melt outside their host crystals, boundary layer enrichment of trace elements during crystallization, and use of hourglass inclusions to understand magma ascent rates. Rigorously placing melt inclusions in a petrographic context has been a characteristic of Fred's approach, which he has recently extended to zoning in quartz revealed by cathodoluminescence imaging.

"Many of Fred's discoveries of recorders of igneous processes are the result of his characterization of carefully chosen samples, involving exceedingly tedious preparation and manipulation of tiny things, in order to reveal elusive patterns in nature. He has led the field of melt inclusion research because he has noticed things, measured them, and extracted information about processes others would have missed. A prime example is that of hourglass inclusions, named by Fred, which have leaked bubbly melt to the outside of their host phenocrysts. Rather than ignoring hourglasses as irrelevant to preeruptive conditions, he used them to quantify ascent times of vesiculating magma. The emphasis in analysis of volatiles dissolved in melt inclusions has been on preeruptive concentrations. Fred has taken the subject a step further and, with Paul Wallace, has constrained actual volatile content, the amount of exsolved gas at subsurface conditions. This achievement has a profound impact on determining bulk magma properties that affect eruptive style and that can be related to geophysical data on active magmatic systems.

"We are recognizing Fred Anderson for his pioneering work on melt inclusions and his leadership in this burgeoning field, particularly in the last decade. I am compelled to note, however, some of Fred's other major contributions. Early on, he proposed a fundamental subdivision of anorthosites into sodic and calcic varieties, a distinction that is still an issue in anorthosite petrogenesis. In the early 1970s, he was senior author on a seminal paper on oxygen isotopes in co-existing phases in igneous rocks, their significance for geo-thermometry, and fractionation of isotopes during crystallization differentiation. His 1976 paper, 'Magma mixing: Petrological process and volcanological tool,' was ahead of the stampede that recognized that this process, neglected for decades, is a widespread and important factor in understanding the diversity of magmas and many petrographic features of igneous rocks. His publications on Kilauea reveal general processes of crystallization, degassing, recharge, and mixing in a basaltic magma reservoir. Revisiting Fred's papers the other day, I was reminded of some themes that run from the early 1970s to the present and that were not widely embraced when Fred introduced them, but have since become accepted truths, namely, the value of melt inclusions as recorders of magma and volatile history, the high preeruptive concentrations of water in arc magmas, and the near ubiquity of magma mixing.

"Having studied his papers on Fe-Ti oxides when I was a graduate student, I eventually met Fred Anderson in 1979 on an AGU field trip to the Columbia Plateau. He and Dave Harris were in the seat behind mine in an ancient school bus. Memories of conversations with Fred on the bus are still vivid for me, along with the pain of being squished, for hundreds of miles, into a minimally padded bench seat intended for children. Fred's visionary thinking and broad insight and his free sharing of his ideas with others came out in those conversations. My experience with this generous man has been typical. A friend wrote, 'his brilliance is accompanied by the complete lack of ego building nonsense. He involves everyone with his thoughts and hides nothing.' Those of us privileged to receive a detailed letter from Fred on some aspect of igneous rocks all others have overlooked, but that leads to exciting new research directions, will attest to the accuracy of that statement.

At Chicago, Fred is known for his patience with students and his willingness to give of his time. He and his wife, Caroline, for many years have been 'Resident Masters' in a large undergraduate dormitory, on 24-hour call for the well-being of over 100 students. His enthusiasm for education extends to giving seminars for teachers in the Chicago area and leading petrologic tours of building stones of downtown Chicago. On top of this, he makes time to be editor of the Journal of Geology.

"In summing up, I will paraphrase some words by a mutual friend. Fred Anderson's low-key demeanor belies his exceptional scientific acuity and creativity. His published work is characterized by extraordinary originality and insight. Still, his three-decade effort on melt inclusions stands as a single, unified contribution whose importance cuts across disciplinary boundaries and time, and it is for this in particular that he is receiving the Bowen Award. Nature has given us few precious tools with which to look backward through time in the reconstruction of geological processes. A special genius is often required to recognize one of those tools. In the case of melt inclusions as indicators of preeruption volatile contents of magmas, we have Fred Anderson to thank-first for recognizing the potential of melt inclusions to disclose information, and second for having the perseverance and resourcefulness to prove their value."

—Charles R. Bacon, U.S. Geological Survey, Menlo Park, Calif.

Response

"Thanks a lot for your generous words, Charlie! I feel very honored to receive the Bowen Award.

"It is indeed a special pleasure for me, a geologist from the University of Chicago, to receive this award. Bowen was a member of our department for part of his career, and his student Julian Goldsmith founded our modernized department and was its chairman when I joined it in 1968.

"For this response, I thought that perhaps you might like to know how I got started on melt inclusions.

"My dissertation under Rob Hargraves at Princeton was a field and mineralogical study of an anorthosite massif in Quebec. It taught me two things: first, that minerals do not a magma make and; second, that mineral separation is tedious and messy. I tried to use mineral compositions to constrain the composition of the melt from which the anorthosite formed. My effort failed. Not because of me, mind you! Nor of Hargraves. It was only that the mineral/melt partition factors were unknown, so knowing the mineral compositions was of little use in reconstructing the magmatic liquid. Anyway, that is how I justified my failure.

"My frustrations led me to try and determine the mineral/melt partition factors by analyzing volcanic phenocrysts and their host glass or groundmass. First I turned to oxygen isotopes and spent 2 unforgettable years working in Clayton's lab at Chicago as a postdoc. Clayton allowed me great freedom, and together with his assistant, Tosh Mayeda, we determined the partitioning of oxygen isotopes between basaltic glass and phenocrysts. My wife reminds me that I had collected these rocks during our honeymoon in Hawaii. Well, I never could get my priorities quite right! Anyway, using my anorthosite mineral separation skills, I laboriously separated the crystals and glass using standard, messy methods. Yes, there was life before the electron probe!

"While at Chicago working with Clayton, I met Ian Carmichael, who had come to visit his fellow countryman, Joe Smith. Joe was developing an electron microprobe, the machine that made my mineral separation skills obsolete. I should have panicked, I think. First, my dissertation goal was a failure; second, the skills that I developed were already obsolete! Well, Buddington had told us that this would happen, so at least I was emotionally prepared.

"Carmichael and I had similar goals. We went on a collecting trip to northern California. In the Medicine Lake Highlands we were nearly killed. It happened on a one-track logging road when I rounded a sharp bend right into the path of a loaded oncoming logging truck. It is a matter of physics that they are incapable of stopping quickly. There was no choice, and I swerved our tiny Volkswagen bug into the forest; Ian's huge inertia almost flung him out of the car. The dust settled. Somehow the truck had missed us.

"While I was still a postdoc working with Clayton, I went to the Jemez volcanic field, New Mexico. There I met Bob Smith, Roy Bailey, Ray Wilcox, and Herb Shaw. This convinced me to accept a job with the USGS. It was a dream for me to be associated with these people and their colleagues, especially Dave Wones.

"Wones gave me excellent criticism, both severe and friendly, which helped me navigate the Survey internal review process. Some of you can attest to how useful this would be! I also learned a very valuable lesson about experimental lab work. Dave assigned me the task of making wustite. The idea was to pass hot hydrogen gas over finely ground magnetite. After a number of explosions, both Dave and I decided that experimental work was not for me. I appreciated Dave's magnificent mentoring, and I was devastated when he later died in a car wreck.

"At the Survey, I was assigned an office space in the corner of the lab of Paul Barton. Paul also was very generous in helping me. Ed Roedder was a few steps away. It was impossible not to become interested in inclusions with Roedder close by.

"Thus I began to analyze melt inclusions, especially for their volatile content. With the electron probe I could directly measure both chlorine and sulfur. Water was a guess.

"For my mineral separation work at the Survey, I used facilities at the Navy Yard, where a number of USGS scientists had their offices and labs. There I met Paul Greenland and Dave Gottfried, and we had great fun thinking out loud together. It was a marvelous experience. Gottfried was a walking library, and he told me about Larsen's work on magma mixing. Sadly, Gottfried had a stroke and died a few years ago. I learned a lot from Dave, and I miss him.

"A pivotal experience occurred after I presented one of my first studies of volatiles in melt inclusions at an AGU meeting in Washington, D.C. After my talk, Pat Hurley came up to me and congratulated me on an important study. He urged me to keep focusing on the volatiles. We had not met previously, but thanks to Gottfried, I knew who he was.

It gave me a great boost to get Hurley's compliment. From then on, volatiles were the main focus.

"During my 2 years at the USGS I enjoyed a brief stay at the Hawaiian Volcano Observatory. There I worked with Tom Wright and Dick Fiske. They had been struggling with the compositional variations of Kilauean basalts and had decided that magma mixing was part of the story. Magma mixing was not one of Bowen's favorite petrologic processes, but I had three votes for it: Larsen, Wilcox, and Wright. That was enough for me. I interpreted melt inclusion compositions in terms of magma mixing. This is still going on, perhaps wrongly.

"Both the University of Chicago and my colleagues there have been enormously supportive of me, both funding-wise and intellectually. Nowadays people may chuckle when I tell them that my start-up package was a $6K Zeiss microscope. But that was in 1968, and it is still my primary research tool.

"At Chicago, I came to rely increasingly on students, and I want to emphasize their extremely valuable contributions. I will single out just a few. First there were Dave Harris and Emi Ito, with whom I began to explore the evidence of water in magmatic melts revealed by melt inclusions. Harris built a machine that yielded some of the earliest direct determinations of water in melt inclusions.

"Christine Skirius came along at the time Stolper and Newman were developing the spectroscopic method for analyzing water and carbon dioxide in silicate glasses. Chris developed the procedures for applying it to glass inclusions in phenocrysts. This gave us the ability to estimate the depth of origin of melt inclusions and their host crystals to a resolution of about 200 meters. As the Bishop Tuff magma body was at least 3000 meters thick, this is a very helpful resolution in terms of tracking the movement of the crystals in the magma.

"Another Chicago student, Fangqiong Lu, worked with Andy Davis and me to analyze trace elements in melt inclusions using the Chicago ion microprobe. Initially, I tried to discourage Lu from doing some of the work she did, like analyzing phenocrysts, which I thought Hildreth had beaten to death. She went ahead and discovered the reverse zoning of sanidine phenocrysts and inclusions of anomalous magnetites in some quartz phenocrysts. Andy Davis pointed out that the barium and strontium in melt inclusions varied in a way that is incompatible with magma mixing. Our results were so troubling that it took us three rewrites, two rounds of reviews, and almost a decade to get them published. Eventually our interpretation retreated away from magma mixing to a Bowenesque concept of crystallization and sinking of crystals.

"Among the other students who helped me with our Bishop work are five undergraduates: Nate Brown, Dave Lorenz, Paulina Mundkowski, Aaron Borowski, Bret Peppard, and Joe Dufek. Their work was phenomenal and essential.

"I was very lucky to have Paul Wallace come and join me as a postdoc working on the Bishop magma. Paul made a magnificent contribution. I think that the work he did to establish the presence of exsolved gas in preeruptive magma changes our view of rhyolitic magmas fundamentally. Without his help, I know that I would not be standing here today. Paul, thank you very much.

"I want to express a very special thanks to Wes Hildreth. Wes generously shared some samples with us at an early stage. He very importantly and generously continued to keep us abreast of field relations that he and Colin Wilson were developing. Wes often reminded me that our study was limited to only a few samples. This is still true. But he led us to the best samples, and our progress depended on that. Best is better than most. We can argue that later.

"I want to especially thank Charlie Bacon for his continuing encouragement. Charlie went out of his way to mention his interest in my work on several important occasions, and he has been steadfast in his scrutiny of my manuscripts. He always makes me think, a lot!

"Before ending, I want to share a funny story about Paul Wallace and myself. In addition to our joint work on the Bishop Tuff, we also worked on Kilauean basalts. In connection with that we had a collecting trip to Hawaii. When in Hawaii I always take an hour or so to check out the hundreds of Hawaiian shirts in Hilo Hattie's huge store. Yes, Chicago does have days when Hawaiian shirts are in style!

I got myself a new shirt. I wore it the next day, much to Paul's amazement and our mutual delight. He had earlier gotten exactly the same shirt for himself! It was then that I realized how much we really do think alike!

"I want to end by thanking my wife, Caroline, and our two children, Eric and Doug. With me they made many spring and summer trips on I-80 to northern California. We got to know practically all the campsites and playgrounds between Chicago and Mount Shasta. We so often ended up in the mountains that my boys identified summer with snow. I had a lot of fun on these field trips, and I am especially glad that my family could be with me then and that my wife is here today.

"I thank you all very much. What a great feeling I have! Thank you again."

—Alfred T. Anderson, University of Chicago, Ill.

The 1996 N. L. Bowen Award was presented to Charles Langmuir at the AGU Fall Meeting on December 16, 1996. The award is given by the Volcanology, Geochemistry, and Petrology section for a single outstanding contribution to volcanology, geochemistry, or petrology made during the preceding 5 years.

Citation

"It gives me great pleasure to have the honor of introducing Charles Langmuir as the 1996 recipient of AGU's Norman L. Bowen Award. Charlie is a fitting recipient of this award. Like Norman Bowen, he is a great scientist whose origins go back to Canada and one who has keen insights into both broad- and fine-scale processes of igneous petrogenesis. As a leading petrologist-geochemist of our time, Charlie distinguishes himself by his quantitative approach to major and trace element studies of basalts.

"Charlie graduated from Harvard in 1973 with an honors degree in the history of science and geology. Following this, he went on to receive his Ph.D. from the State University of New York, Stony Brook, in 1980, under the guidance of Gil Hanson. After a year as a postdoctoral fellow at Lamont-Doherty Geological Observatory, he joined the faculty of Columbia University and is now their Arthur Storke Professor.

"A hallmark of Charlie's approach is that he begins by making a simple geochemical observation and proceeds through quantitative modeling to reach startling results with far-reaching implications. Amazingly, it was Charlie's first published paper where he immediately had an impact on his field. In this paper, on basalts from the French-American Mid-Ocean Undersea Study (FAMOUS) area of the mid-Atlantic Ridge, he helped us all to begin to understand the realistic complexities of melting processes with the concepts of incremental melting and residual porosity. Charlie reasoned that these basalts, which possessed crossing rare earth element patterns and constant ratios of isotope and highly incompatible trace elements, were produced by dynamic melting,' where melting and melt segregation, with partial melt retention, occur continuously during adiabatic ascent.

"Charlie is an innovator who thinks deeply and unconventionally about the way nature works. While many others were projecting into Ca-Mg-Al-Si phase space, Langmuir demonstrated that major element compositions could be treated in other ways with new ideas to be gained. Together with Gil Hanson, he used a novel premise that major element variations in multicomponent magmatic systems could be modeled using the same quantitative methods involving distribution coefficients that are successfully applied to trace elements, with the added constraint of stoichiometry. Charlie later presented a more generalized approach with his widely used liquid line of descent modeling program (1990), originally written for one atmosphere crystallization and more recently adapted for modeling crystallization at higher pressures (1992).

"Charlie has clearly been a great inspiration to our next generation of petrologists and geochemists; I will give but three of many examples. First, working jointly with students Emily Klein and Terry Plank, he led a major revolution in thinking about the petrogenesis of mid-ocean-ridge basalts. Starting with the now classic 1987 paper by Klein and Langmuir, they showed that regional averages of basalt chemistry correlate with both the depth and crustal thickness of the ridge axis from which the basalts are recovered. Global correlations in key chemical parameters (e.g., Na8.0 and Fe 8.0) were shown to reflect a fundamental association between the extent of melting and the pressure of melting, which in turn appears to result from regional variations in subsolidus mantle temperature. In 1989, Charlie revealed for us the important consequences of in situ crystallization in a boundary layer using simple and elegant quantitative modeling. Later, with Terry Plank, he evaluated the effects of melting regime and mantle flow paths beneath ridges and predicted that continuous mixing of melts occurs beneath ridges with high degree melts dominating. All this culminated with their tour de force published in AGU monograph 71 in 1992.

"Second, Charlie and his graduate students have also made important contributions in the field of arc magma petrogenesis. In 1988 Terry Plank and Charlie showed that chemical parameters indicative of the extent of melting correlate with the thickness of the arc crust. This surprising find was explained in terms of variations in the height of the melting column above the downgoing lithosphere imposed by variations in the thickness of the overriding crust, a model that has excited a good deal of interest and controversy.

"Third, Charlie and his students have developed a high-quality geochemical laboratory. Initially established with a direct current plasma emission spectrometer, this lab maintained the Langmuir tradition in that it was dedicated to major and trace element measurements on the same samples. Going beyond the traditional fare, Charlie, in collaboration with Jeff Ryan, published a series of studies in 1987, 1988, and 1993, reporting on the abundances of lithium, beryllium, and boron in a wide variety of lavas and ultramafic rocks. These innovative studies on light elements have had a significant impact on the community, including providing constraints on magmatism at ridges, arcs, and intraplate settings, and adding to our understanding of the evolution of ocean island basalts and their abundances in the bulk silicate earth.

"Professor Langmuir's contribution to basalt geochemistry on a global scale, his quantitative approach to combined major and trace element studies, and his application of these chemical observations to developing physical models of melting and melt extraction place him among the leading international workers in this field. A number of his graduate students have gone on to establish themselves as distinguished scientists in various universities. There are very few scientists working in these fields accorded the universal respect that Charlie has gained. In the words of Claude Allegre, and I am sure they are shared by those of us here, Charlie is an imaginative and extremely bright scientist, and also a perfect gentleman.' It gives me great pleasure to present to you the Bowen medalist for 1996, Charlie Langmuir."

—William McDonough, Harvard University, Cambridge, Mass.

Response

"Thanks very much, Bill, for those generous comments. I am very grateful to receive the Bowen award from the Volcanology, Geochemistry, and Petrology section, particularly so since I have such high regard for the past recipients, many of whom are my scientific heros. I feel fortunate to be one of their number.

"One of the advantages of receiving an award like this is that it leads to reflection on how it happened, and an appreciation for all the people who helped: a mentor like Gil Hanson, gifted students, generous and patient colleagues, stimulating and contentious postdocs, and those who were willing to take the time from their busy lives to write supporting letters. Of course, I owe an enormous amount to my wife, Diane, who was able to hold our home together, and give me the flexibility and time that creative science requires. Adequate thanks to all these people would take up all of the time available, because the thanks are long and each one is a special case.

"There is one specific debt that I would like to acknowledge at more length, however, and that is my debt to my parents, who are present here tonight. When I was a boy, my father played at science with me: working with Cartesian divers, dry ice, and liquid nitrogen; seeing how the tone of a flute would change if you blew CO2through it; growing crystals; and making simple instruments. The combination of fun, amazement, and analysis that my father conveyed was a source of frustration to my grade school science teachers, because I knew that science was a lot more fun and interesting than the boring books we were reading. To this day, I feel that I learned more from those very early experiences concerning what science was and how to go about it than from all my schooling until graduate school. The debt to my mother is more subtle, but somehow she conveyed that exploration was infinite, that a sense of humor was essential, and that there was no sense in feeling limited, even if you were. I feel very much that many of the good things that have happened to me come directly from their influence.

"In general, I feel somewhat uncomfortable with awards of this kind, because of the way that I find science happens. For me, ideas sometimes miraculously come together in discussion in front of a whiteboard, and without the questions from and interaction with the other person, nothing would happen. On a very broad scale, ideas often appear to different people at the same time, because that is the natural evolution of the field. That is why, I think, some of the most important developments have us reacting with Of course! I knew that!' because the idea was there in the scientific atmosphere, just waiting to crystallize. Moreover, in each specific instance, ideas often appear because of the subtle chemical interaction between two people confronting a problem together, or going over a paper in a seminar, or even listening to a talk on an apparently unrelated subject. I view this award as being the result of those interactions, and hence it is shared in a real sense with the large number of people I have worked or interacted with over the years.

"The work for which this award is given came about from a series of bizarre accidents. I took only a few geology courses as an undergraduate at Harvard and spent most of my time doing theater. The most daunting and boring course I took was petrology/mineralogy, from Thompson and Burnham. I went sporadically, and there was always this one student sitting in the middle of the second row, with 10 or 20 kilograms of notes and notebooks piled around him. The lectures were an arcane dialogue between the professors and this dedicated individual, some guy named Stolper. I knew from this experience that although I liked geology, petrology was no field for me. It was only much later, actually, when reading Bowen, that I came to appreciate the beauty of the field.

"After a year pursuing a career in theater, I went to graduate school in the one place that had been willing to accept me and defer admission: The State University of New York at Stony Brook. I wanted to study either geomorphology, because you could see what was happening, or economic geology, because the minerals were pretty, but to my surprise found no one in these fields in this small department. I liked Gil Hanson's geochemistry course, but Ted Bence was the one with some funding, so we compromised and I worked in Gil's lab on Ted's rocks: ocean ridge basalts. No subject could have had less promise—fine-grained black rocks that were all the same, with no pretty minerals at all, and they had been characterized already—our seminar at the time had a complete list of mid-ocean ridge basalt petrology papers, and it filled a whole page. However, Gil assured me that there are no bad problems, only bad scientists, and that with good data and thinking,' things would turn out all right. I think one might add that it helps if the bad problem' is a virtually unexplored frontier that has produced two thirds of the Earth's surface.

"Later, landing at Lamont-Doherty Geological Observatory as a postdoc, I was somewhat at loose ends, since there was no postdoctoral adviser and poor equipment. Henry Dick came through Lamont one day and said You know, what Lamont needs, and what the field needs from Lamont, is a sea-going petrologist.' I was a lab scientist, and with no experience there was no chance of getting a sea-going proposal funded. Then a short time later, a Sloan Fellowship gave me the funds to go to sea and learn the ropes from a generous geophysicist, Brian Taylor, which made it possible to embark on a series of investigations of that wonderful frontier of the sea floor.

"I had no idea of the excitement of sea-going science. At ocean ridges, you can see structures that are the direct result of related magmatic and tectonic processes and pose clear hypotheses that can be tested by a combination of geochemical and geophysical methods. This leads to a problem-oriented approach and inevitable cross-fertilization among fields, rather than a specialty-oriented approach. Petrology as a field became a tool for study of the Earth. We're after a solution to the problem, of how the Earth works, and that requires combining the physical and chemical aspects into a unified model. So instead of plotting major elements on a triangular diagram or one trace element versus another, we started plotting geochemical parameters versus geological and geophysical parameters: distance to a transform fault, axial depth, crustal thickness, and mantle Bouguer anomaly. These relationships of geochemistry to real physical observables of the Earth inevitably lead to models that tie together the geophysics and geochemistry and make geochemistry real.' A unifying goal that now spans many fields is to find the important relationships among geochemical and geophysical data and how both relate to quantitative models of the Earth system.

"The ocean ridges are best suited to this approach—they demand it—because sampling and geophysics inevitably follow on together from a new map. The problems leap out at you from the map on the page. The combined understanding of the processes of melting, melt migration, and differentiation in magma chambers that have come about through the study of ocean ridges now are seen to cast new light on petrogenesis in many other igneous environments. So starting from boring black rocks that are all the same,' I now view ocean ridges as the Rosetta stone' of igneous petrology. They reveal how igneous systems work and that understanding can then be applied to other settings. For example, the work that we have done on convergent margins builds upon the paradigms from the ridge developed with Emily Klein. The work with Terry Plank showing how sediment inputs correlate to volcanic outputs could only come about because of the understanding of how the mantle melts and the global systematics of both ocean ridges and convergent margins that relate geochemical data to geophysical data and real tectonic variables. In fact, it is often only with the understanding of ridges that many other igneous terrains can be interpreted and understood.

"I consider now that petrology' is no longer the appropriate title for much of what many of us do. We are working on problems that relate to the circulation of the solid Earth, to linkages between different parts of the Earth system, to understanding how the whole Earth functions, and to learning more about this marvelous machine by whatever means are necessary. What is most exciting are the unforeseen linkages between the different parts of the system, as we discover that all parts of the system are far more connected than we have been able to imagine. What could be more lucky than continuing to be able to participate in this accidental adventure?"

—Charles H. Langmuir, Lamont-Doherty Earth Observatory, Palisades, N.Y.