Citation for Craig Manning
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
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
Citation for Bernard Marty
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
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