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.”
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.—Jonh P. Grotzinger, California Institute of Technology, Pasadena
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