Citation by K. Kelly
The following citation was prepared and delivered by K. Kelley (USGS Denver):
President Relvas, ladies and gentlemen, I am honoured to present the citation of Dr. David LEACH – the sixth recipient of the SGA-NEWMONT GOLD MEDAL. This is our society’s highest award for an exceptional career in ore deposit research. Dave graduated with an undergraduate degree from Virginia Polytechnic Institute, and then continued at the University of Missouri, where he obtained his Ph.D. degree in 1973. He worked for the Lawrence Livermore National Laboratory for several years, and joined the USGS in 1976. He “retired” in 2009 from the USGS and has been with Global Geoscience Consulting ever since. He also currently serves as a Research Professor at the Colorado School of Mines.
I first met Dave when I started my career with the USGS in 1980. At that time, he was building a world-class fluid inclusion laboratory, and together with a group of young scientists, he took the lead on ore fluid studies of MVT Pb-Zn deposits in the US. These data led to a number of classic papers in the 1980s that indicated the then-existing MVT model relating ore formation to normal sedimentary basin evolution was incorrect. Instead, David and colleagues showed how orogeny led to continental-scale flow systems that formed MVT deposits. In subsequent years, he tested these pioneering ideas that proved consistent for deposits all over the world, including those in Europe, northern Australia, and North Africa.
David also became active in the study of clastic dominated Pb-Zn deposits, otherwise known as SEDEX deposits, including the giant Red Dog deposit in Alaska. This work allowed my path to cross directly with Dave’s, and I spent many gratifying years working with and learning from Dave’s vast experience with sediment-hosted deposits. As evidenced by his invitation to take the lead on the benchmark paper in the Economic Geology 100th Anniversary Volume, the research conducted by Dave has greatly influenced our present-day thinking on ore genesis of sediment- hosted Pb-Zn deposits. Most recently, David has focused his research on the secular evolution of sediment-hosted Pb-Zn deposits, with significant papers relating ore formation to ocean evolution, passive margin development, changes in Earth oxidation, and supercontinent evolution. He has applied his knowledge to Pb-Zn deposits in China, and has developed a salt diapir model for the giant Jinding deposit, a model that has changed exploration criteria for Pb-Zn deposits. In
summary, no one has contributed more in the past 40 years to our understanding of Pb-Zn
metallogeny than David Leach.
One of his greatest contributions is his role as a leading mentor in economic geology. He has devoted endless time to helping students and young scientists within the USGS, as well as Australia, China, Europe, and northern Africa. David’s collaborations and mentorships are obvious from his extensive publication record. He has authored or coauthored more than 150 papers, including articles in Economic Geology, Geology, Mineralium Deposita, and several book chapters. He has presented invited talks on his research in more than 25 countries, some as an SEG-International Exchange Lecturer, and he has chaired or led countless sessions and workshops at international conferences. David’s accomplishments have led to numerous awards, including the 2009 USGS Meritorious Service award and the SEG gold medal in 2010.
Among his most significant contributions has been his long-term involvement and commitment to SGA, first serving as Regional Vice-President for North America, then VP and President of SGA, and then as Treasurer. His involvement was instrumental in bringing SGA to North America and in making it an international society of ore deposits research. On behalf of SGA I would like to congratulate Dr. David Leach for this prestigious award. We look forward to many more achievements from him in the geosciences, and we wish him well on all his endeavors, together with his wife Susan and their children and grandchildren.
The following acceptance speech was delivered by D. Leach:
Thank you, Karen, President Relvas and Dr. Pasava.
I am deeply honored to receive the prestigious SGA Newmont Gold Medal. I am thankful to the SGA council and the nomination committee.
As a recipient of a career award, I recognize that professional success depends on the people that have been part of my life's journey. I view this award as a reflection of the exceptional people that I have worked with and the opportunities provided by organizations I have been associated with.
The study of ore deposits has been more than a profession or a job, it is a life style that I have approached with passion and excitement. The most difficult part of my journey has been trying to find a balance between my love for science and the most important love in my life-- my family. Fortunately, my wife Susan has been the rock of my family, understanding, encouraging and truly essential to my journey.
My journey began when I started graduate work under Alden Carpenter, a pioneer in the study of sedimentary brines that would become a foundation for understanding the genesis of sedimentary rock-hosted ore deposits. I was fortunate to have joined the USGS during its golden age of ore deposit research. My first projects included working on the giant polymetallic veins of the Coeur d'Alene district with Al Hofstra and Gary Landis, and on MVT deposits in North America with Don Sangster, Elisabeth Rowan, Dwight Bradley and John Viets. An adventurous and colorful time during my journey was the early work on orogenic gold systems with Rich Goldfarb- I could write a book on the "Goldfarb period." The most intensely productive period in my journey was the USGS Red Dog deposit project with Karen Kelley, Erin Marsh, Craig Johnson, John Slack, Julie Dumoulin and the Red Dog team. Lessons learned from the Red Dog studies provided the foundation for new perspectives on world sediment-hosted ores that included contributions from Dwight Bradley, Sergei Pisarevsky, David Huston, Ryan Taylor and Garth Graham.
A remarkable period of my journey began after I visited the University of Paris in the early nineties and met Professor Ghislain de Marsily. Thanks to Ghislain, I began a nearly 10-year period of collaboration on MVT deposits in Europe and North Africa --which marked my transition from a provincial perspective of MVT ore systems to global systems.
After retirement from the USGS in 2010, I am now enjoying a period of "re-discovering MVT systems"and learning about the importance of evaporites-bearing rocks in ore genesis with Song Yucai at the Chinese Academy of Geoscience in Beijing and Salah Bouhlel at the University of Tunis.
Finally, my career included working with SGA --- sharing time with dedicated and generous geologists to advance ore deposit studies and to help students move forward in their career. My time serving SGA will continue to be one of my most satisfying professional memories.
My great appreciation to SGA and Newmont for this recognition of my geological journey with my colleagues.