Citation by Alex Webb
Dr. Andrew Zuza is a model geologist for his generation: he is an exceptionally adept field-mapper with impressive mathematical skills who is able to synthesize large amounts of geological data in an imaginative and original fashion. He is unafraid to challenge established ideas. These talents, in combination with his indefatigable and good-humoured passion for science, have made his research accessible and transformative. His seminal contributions include advancing our understanding of strike-slip-fault system kinematics; elucidating the tectonic evolution of northern Tibet; quantifying continental fault strength and crustal rheology; development of provocative tectonic models for the evolution of the Central Asian Orogenic Belt and the North American Cordillera; documenting substantially non-lithostatic pressure in the middle crust; and many more.
Andrew started his geology education at Cornell University, mentored by Prof. Chris Andronicos and this year’s Penrose Medalist, Prof. Sue Kay. An undergraduate research project based on intra-plate volcanism in Mongolia honed his interests on central Asian tectonics, and in 2011 Andrew joined UCLA to pursue his PhD with the late Prof. An Yin. They worked together on strike-slip fault systems and their implications for crustal and fault rheologies, on the tectonics of northern Tibet and central Asia, and on a variety of field research and teaching endeavors across the western United States. An previously noted: “Andrew is someone very special: he is one of the best mappers I have known across all age groups … he is one of the most creative young Earth scientists of his generation. His transdisciplinary research has reshaped the modern landscape of tectonic studies and structural geology.” Upon finishing his PhD in 2016, Andrew was hired at the Nevada Bureau of Mines and Geology at the University of Nevada, Reno, where he is now an Associate Professor.
Andrew’s research melds field mapping, quantitative analysis, and geologic synthesis to yield new insights in the field of continental tectonics. He has made several major discoveries:
Andrew has refined our knowledge of crustal-fault strength and rheology via creative observations of crustal geometry and thermal structure. He combined a stress-shadow model and results of analog experiments to establish a scaling law that relates strike-slip-fault spacing to fault friction. His work showed relative differences in fault strength between active strike-slip faults in central Asia and the San Andreas fault system. Later, he and his colleague Wenrong Cao combined heat flow, GPS, and earthquake hypocenter data in California to show that the standard flow laws match well with the seismogenic-layer thickness and that heat flow plays a first-order role over strain rate in controlling crustal strength profile.
A substantial portion of Andrew’s contributions have come from the arena of Tibetan tectonics. Over the past decade, he and collaborators have been unravelling the interrelated topics of Proterozoic-Paleozoic assembly of the Asian continent and the Cenozoic reactivation of such structures during the Cenozoic India-Asia collision. His approach of carefully investigating both old and young geology based primarily around field observations has allowed Andrew to extract unique insights regarding the evolution of central Asia. Systematic reconstruction of Paleozoic-Cenozoic deformation across Asia led to the development of his Balkatach hypothesis that posits the existence of a ~6000-km continental strip along the southern margin of the Paleo-Asian Ocean. This model reinvigorates the debate concerning what bounds Laurentia during the formation of the supercontinent Rodinia. Mapping of Paleozoic suture belts across northern Tibet refined our understanding of the northern Tethyan realm, including the discovery of coeval eclogite generation along a ~3000-km-long arc system interpreted to result from punctuated subduction erosion. Building on this, Andrew has shown how these preexisting pre-Cenozoic structures were reactivated shortly after the India-Asia collision to shape the northern extent of the Himalaya-Tibetan orogen. This includes documentation of multi-level duplexing in crustal thickening and the partitioning of deformation between thrust and major strike-slip faults.
Much of Andrew's recent work in the North American Cordillera highlights his readiness to challenge existing models based around fundamental field observations. For example, Andrew made a major contribution to a hugely controversial subject in the study of continental tectonics: preservation of significant non-lithostatic pressure in the rock record. The question is whether or not one of our most common assumptions holds: that pressures determined via traditional geobarometry equate to lithostatic depths. Via field observations and a high-resolution temperature versus depth dataset, Andrew showed how the estimated peak metamorphic pressures in the Cordillera hinterland far exceeded any plausible burial depth there.
Another major front in his re-exploration of seemingly established knowledge is refined investigations of metamorphic core complexes via detailed field mapping. His work reveals how the ductile mylonitic shear zone of one such core complex formed much earlier than, and is thus temporally decoupled from, the brittle detachment fault system that developed during the initiation of Basin and Range extension. His research group’s continuing work on such systems has reinvigorated buoyant gneiss dome models for these metamorphic core complexes, and subsequent geologic synthesis and modeling shows how the spacing of metamorphic core complexes in the western US may simply be a product of diapirism in variably thick crust.
This review of Andrew’s scientific contributions is substantially incomplete: both his productivity and range of interests are exceptional. In my view, his closest comparable is his PhD supervisor, a phenomenal Donath and Penrose medal winner, the late An Yin. Three shared characteristics are uncommon ability to interrogate received geological “truths,” very high rates of high-quality hypothesis generation, and massive capacity for synthesis. Seemingly every month he brings forth a new paper with a major step forward on a completely different topic than those of the prior months. Individually, the new concepts seem straightforward – although commonly there is a step or three that connects the dots ingeniously. Considering his contributions collectively, Andrew is a major accelerant for our field, lighting up a brighter future for continental deformation research.
Response by Andrew V. Zuza
I am incredibly honored to receive this year’s Donath Medal. I am grateful to the Geological Society of America and to the Donath family for endowing this award. I also want to sincerely thank my nominator An Yin, citationist Alex Webb, and letter writers Eric Kirby, Paul Kapp, Brian Horton, Carmie Garzione, and Mark Harrison.
My passion for Earth Science research developed while working with two mentors at Cornell University: Chris Andronicos and Sue Kay. I was extremely fortunate to have several enriching experiences during my undergraduate studies that ultimately cemented my desires to pursue Earth Science research. I attended the Cornell Andes Summer Field course led by Sue Kay and Victor Ramos, participated in a field-based semester abroad in New Zealand run by Darren Gravley and Max Borello, and joined a research trip to Mongolia based around the geology of central Asia organized by Karl Wegmann and Kurt Frankel. I greatly appreciate the immense efforts by all of these individuals to organize such formative experiences for undergraduate students, which certainly impacted the trajectory of my life and career. These undertakings exposed me to the exhilarating challenges of remote geologic fieldwork while igniting my fascination with large-scale tectonic studies. It was a perfect blend of science, adventure, and camaraderie. I was hooked!
I went on to join An Yin at UCLA for graduate studies. My time at UCLA transformed me into the geologist I am today, with guidance from An, Mark Harrison, and Craig Manning. Southern California was an incredible place to learn about a variety of geologic processes during geologic excursions around the western US. I cherish the enriching interactions with my grad-student peers who went on to become professors, industry experts, and even an astronaut! Some of my closest collaborators and friends came through the UCLA geology program, including Peter Haproff, Margo Odlum, and Alex Webb. It was here that I also met Robin—a great structural geologist and leading geothermal exploration scientist—who later became my wife. I extend my heartfelt thanks to Robin, and our children Owen and Ainsley, for their unwavering support.
I treasure my Chinese colleagues with whom I have worked over the past decade, including Gong Junfeng, Cheng Feng, Li Bing, Xu Xi, my long-term friend and collaborator Wu Chen, and countless others that have shown unbelievable hospitality, compassion, and support to me through the years. I look forward to fruitful and far-ranging collaborations for many years to come.
An Yin was a larger-than-life mentor, who passed away unexpectedly just a few months ago doing what he loved: teaching field camp for undergraduate students at UCLA. I had the pleasure of spending many summers with An in the White Mountains of California and travelling around the world to incredible field sites. He taught me how to drive my science based on field observations and, above all, my own curiosities. An was especially adept at taking complex problems and distilling them to simple conceptual or analog models, often using Play Doh, crunchy peanut butter, sand, fallen ceiling tiles, or Hi-Chew candies to explore and explain the physical viability of a hypothesis. His love and respect of our science was infectious, and he had an unmatched knack for training students to think both critically and creatively. I owe much of my career and success to his unwavering support, encouragement, and guidance.
After obtaining my PhD, I joined the Nevada Bureau of Mines and Geology at the University of Nevada, Reno. Here, I’ve gained a deeper appreciation for science that addresses both basic and applied questions in the Earth Sciences. This work has challenged me to investigate academic questions about how and why the continents deform, but also to think critically about related societal issues rooted in the energy, resources, and hazards sectors. I work with extraordinary colleagues and students to better understand the intricacies of continental tectonics, with methods spanning from high-level continent-scale syntheses to detailed geologic observations published as quadrangle maps. I have thoroughly enjoyed and learned from working with UNR colleagues Wenrong Cao, Chris Henry, Seth Dee, Stacia Gordon, Philipp Ruprecht, Joel DesOrmeau, among others.
The enthusiasm and drive of past and present students inspires me. More than ever before, they are primed to make exciting breakthroughs in the Earth Sciences, with modern analytical tools and numerical techniques, a good foundation of geologic field context to guide focused investigations, and a rich history in our field filled with both misdirections and great successes. While we can, and should, stand on the shoulders of giants, I encourage future Earth Scientists to not be beholden to past interpretations as absolute truths. I look forward to future advances and breakthroughs as we try to figure out how the Earth, and even other planetary bodies, work.
Our geology community thrives when we unite, embrace open discussions and debate, and welcome diverse interpretations. Over the past ~6 years, I have had the opportunity to work with exceptional geologists in Nevada, in areas that they mapped decades ago, including Art Snoke, Keith Howard, and Chuck Thorman. I appreciate their willingness to reveal old outcrops with confidence like they had visited them just yesterday. Chuck, in particular, enthusiastically showed off geology from his PhD mapping done in 1959-1961, and I deeply value this informative experience for his stories, historical perspective, and love of the science. Intriguingly, several decades ago while at the USGS, Chuck had greenlit funding to support student mapping projects in the National Parks, which ultimately funded my advisor An Yin’s dissertation research in Glacier National Park. This anecdote shows the integration and connectivity within our field, including the diverse, yet intertwined paths one may take as a student, survey geologist, academic, industry expert, or other rock enthusiast. Through collaborative support and constructive debates, our community together can address the most pressing basic and applied questions in the Earth Sciences.
Thank you again to the GSA, this wonderful community, and the Donath family for this tremendous honor.