A collection of tributes to Mac from former students, colleagues and friends Alexander Robert McBirney July 18, 1924 – April 7, 2019 Tribute to be published in EOS, Transactions of the American Geophysical Union Alexander R. McBirney (1924-2019) Former West Point graduate and coffee grower transformed igneous petrology and volcanology. Dana Johnston, Dennis Geist, Tony Morse and Steve Sparks Alexander R. McBirney (Mac), a pioneer in the application of physical reasoning and fluid dynamics in physical volcanology and igneous petrology, passed away on April 7, 2019. Over the course of a scientific career that began at the dawn of plate tectonic theory, and spanned some 50 years, he played a key role in our understanding of the physics of magma chamber evolution and the volcanism characteristic of hot spot and subduction zone settings. Mac grew up in California and attended the United States Military Academy at West Point for his undergraduate studies. He had a great sense of humor and a wry wit and always prided himself on having been in the last class that had to demonstrate its prowess leading a cavalry charge wielding a sword on horseback to graduate. From there he took his young family to Nicaragua where he tried his hand running a coffee plantation that he and his crew literally hacked out of the jungle. It was in Central America where he happened upon UC-Berkeley volcanologist Howell Williams who convinced him to leave the coffee plantation to others and join him in the Bay Area for his doctoral studies. Upon completing his dissertation, he joined Scripps Institution of Oceanography literally in the earliest days of plate tectonics. When the University of Oregon came looking for the first members of its newly conceived Center for Volcanology, he answered the call, serving as the Center’s first director and remaining at this institution for the next five decades. Under Mac’s leadership, the Center’s research soon put the University of Oregon on the global map of volcanology and petrology research powerhouses. Among his best-known work in the Center’s early years were experimental studies of the physical properties of igneous rocks and their melts and classic field studies of the Skaergaard layered mafic intrusion in east Greenland and the volcanoes of the Galapagos Archipelago. This latter work was an outgrowth of a 60- scientist expedition to the Galapagos Islands in 1960, organized by the California Academy of Sciences, that Mac had the good fortune to participate in, together with Howell Williams and Alan Cox. This resulted in the publication of GSA Memoir 118 (McBirney and Williams, 1969), a classic study of ocean island volcanism and petrology, which has withstood the test of time. It also led to a lifetime of collaborations, as he introduced others to that remarkable archipelago. Mac was a brilliant and original thinker and in many ways was ahead of his time. He was among the first to interpret heat flow observations at ‘midoceanic rises’ in terms of magmatic intrusion (McBirney, 1963), and to propose that dewatering of subducting slabs likely fluxes melting in subduction zones (McBirney, 1965). He also recognized the lack of good data on key physical 2 properties of igneous rocks and their melts like viscosity, surface tension, density and thermal conductivity. His 1973 paper with T. Murase (Murase and McBirney, 1973) went a long way to rectify this situation and remained a classic and a very influential paper in the 1970’s and 1980’s. He was particularly well known for his recognition that geochemical stratification could develop in magma chambers via sidewall crystallization leading to double diffusive convection, using the Skaergaard layered mafic intrusion in east Greenland as his type example. He built on this work in proposing that such crystallization could result in fractionation of liquid from crystals at a time when most attention was focused on the opposite scenario (McBirney et. al., 1985). He indeed played a major role in recognition of the importance of fluid dynamics in igneous petrology. He also enjoyed a good argument and was sometimes a contrarian, often delivering his views tongue-in-cheek with a twinkle in the eye. Indeed, many igneous geochemists will remember his fictive manuscript, using his nom de plume: Bostok, Derek, 1973, The holium-thulium ratio of kuselite and seafloor spreading: Trans. Phil. Soc. Agua Blanca, 97, 892-897. On a more serious note, he provoked enormous controversy in his later studies of the Skaergaard Intrusion when he pointed out (e.g., McBirney and Sonnenthal, 1990), that many of the outcrop- and grain-scale features appear inconsistent with crystal fractionation by settling or gravity currents, upending a generational paradigm. Instead, he proposed that many of those features are created by near-solidus material transfer (metasomatism) and self-organization. Mac was of another generation and will always represent for many of us one of the last of the golden age of exploration. He was a man of many talents and one with wide-ranging interests. His facility with languages, French, Spanish, German and English, enriched his travel and lent itself to many international collaborations and several highly regarded translations, including F.A. Fouque’s 1879 book on Santorini: Santorini et ses Eruptions (Santorini and its Eruptions, 1999, Translated and annotated by A.R. McBirney, The Johns Hopkins University Press, 495 pp.). Outside of science, he was a skilled cabinet maker, a model train enthusiast and an accomplished bookbinder, skilled in the old ways of the craft. Mac was also the founding editor of the Journal of Volcanology and Geothermal Research. He was a fellow of the American Geophysical Union, the Geological Society of America, the American Academy for the Advancement of Science and was awarded the Bowen Award of the VGP section American Geophysical Union in 1990. Mac is survived by his wife Carmen and daughters Anne and Christine. Dana Johnston (email: [email protected]) Earth Sciences, University of Oregon; Dennis Geist, Division of Earth Sciences, National Science Foundation; Tony Morse, Geosciences, University of Massachusetts; Steve Sparks, Earth Sciences, University of Bristol. 3 Professor Dana Johnston, University of Oregon, colleague; and major recipient of Mac’s generosity and support as a brand-new junior faculty member beginning in 1986 Okay, since I’m compiling this collection, I get to go first!! And…I want to begin with this photo showing Mac in the front-row-center, surrounded by the rest of the faculty members of the Department of Earth Sciences at the University of Oregon at that time. L to R: front row: Harve Waff, David Schmidt, Gene Humphreys, Mac, Kathy Cashman, Josh Roering, Dana Johnston; front row on stairs: Ewart Baldwin, Sam Boggs Jr., Mark Reed (down low), Greg Retallack (up high), Paul Wallace, Ryoske Motani (interstitial), John Logan; back row on stairs: Norm Savage, Dan Weill, Doug Toomey, Jack Rice, Dave Krinsley, Bill Orr. Well…..my Mac story revolves around my initial hiring, in Spring, 1986. Mine was one of the most sought-after job openings in the country that year and, to my continued amazement, I was offered the job. Of course, I immediately accepted because, my God, it was the University of Oregon, the famed Center for Volcanology and McBirney’s department!! However, and this is a big however, Mac was on sabbatical and out of the country when this faculty search transpired. Thus, I had never met the man prior to my arrival as his new colleague in a field very close to his own. And, wouldn’t you know it, I was given a corner office in the Volcanology Building, with metamorphic petrologist Jack Rice to the east, and Mac my neighbor to the north! 4 Well, after moving into my second-floor office, I would arrive each morning on my bicycle and anxiously look out the elevator door to see if Mac’s office was open with the lights on. This went on for several days with no result and then one day, behold, Mac was in! So, I parked my bike in my office and then sheepishly approached his ajar door and knocked. He was extremely welcoming and, after shaking hands and looking me up-and-down, he invited me to sit down, as he wanted to welcome me to the department and wondered how he could help me get settled. Buoyed by this warm reception, I inquired of professor McBirney whether I had it right that people called him ‘Mac’? His reply was what I came to know was classic Mac. He said to me, a complete stranger just minutes earlier, and with a completely expressionless face, that “his friends did”, and he left it at that, with no indication whatsoever whether this would be an appropriate sobriquet for me to use. As it happened, I took a chance and referred to Mac as Mac from that first day forward and he was never anything but the most gracious, generous and supportive senior faculty mentor one could hope to have, and eventually seek to emulate. And, before ‘yielding the floor’, I offer one more departmental group shot, this one from a 2006 faculty luncheon, with Mac now front-center on the stairs: 5 Professor Sir Stephen Sparks, University of Bristol, UK, colleague Thanks for sending the sad news of Mac’s passing. He was without doubt one of the most influential and significant figures in petrology and volcanology of the last several decades. His research on Skaergaard, contributions in physical volcanology and pioneering ideas on magma physics come immediately to mind. He also wrote a super text book and translated the Fouque book on Santorini, the latter showing his scholarship and admiration of past giants of petrology (of course including Wager).