Stephen J. Reynolds

Dept. of Geology, Arizona State University Tempe, AZ 85287-1404 Office: 602-965-9049 -- Dept. 965-5081 Fax: 602-965-8102  

Brief Biography

Note: Excuse the flowery tone of the following biography, which was derived from the ASU Dept. of Geology Brochure. -- Steve


Dr. Stephen J. Reynolds is a Professor of Geology at Arizona State University. Prior to that, he spent 10 years directing the geologic framework and mapping program at the Arizona Geological Survey. During the past 15 years, he and his colleagues completed geologic maps for more than twenty previously unmapped mountain ranges in Arizona. He has completed more than 100 published geologic maps, articles, and reports, including the most recent Geologic Map of Arizona, and he coedited Geologic Evolution of Arizona, an 866-page treatise on Arizona geology. He received his Ph.D. from the University of Arizona in 1982, and has worked for the U.S. Geological Survey and several mineral, energy, and environmental companies. He coauthored the second edition of the popular structural geology textbook Structural Geology of Rocks and Regions with George Davis.

Research Program

Professor Reynolds has an interdisciplinary, field-oriented research program incorporating geologic mapping, structural geology, regional tectonics, geochemistry, thermochronology, ore deposits, and the role of fluids in tectonic processes. A major goal of this research is to investigate how processes involved in the evolution of continents vary with depth.

The tectonic evolution of southwestern North America is complex and has resulted in the exposure of rocks and structures formed at various crustal levels. This provides an opportunity to examine variations in structural style, deformational mechanism, and fluid processes with depth. Prof. Reynolds was one of the first geologists to do detailed structural and geochronologic studies on detachment faults and metamorphic core complexes, and helped discover nearly 10 core complexes in Arizona and adjacent regions. For example, the South Mountains metamorphic core complex adjacent to the ASU campus contains Tertiary mylonite and fault breccia that record the rapid ascent of the rocks through the brittle-ductile transition during extensional tectonism and detachment faulting. In this one mountain range, deformational processes and fluid regimes below the brittle-ductile transition can be compared with those typical of the upper crust.

Field studies, including geologic mapping and modern techniques of structural analysis, are an integral component of most geologic investigations. Geologic field projects of Professor Reynolds, his colleagues, and students are presently focused on (1) kinematics and evolution of major faults and ductile shear zones, (2) mechanisms of crustal extension, basement-involved thrusting, and severe structural attenuation, (3) the relation between fluids and structures, (4) Cenozoic tectonics of the Colorado Plateau - Basin and Range boundary in central Arizona, and (5) applications of TIMS (thermal infrared mapping spectrometer) to bedrock and surficial geologic mapping. These studies concentrate on, but are not restricted to, western North America.

Interactions between fluids and rocks play a major role in the evolution of continental crust, as expressed by metasomatism, hydrothermal mineralization and alteration, and the formation of many fluid-controlled structures. The nature of fluid-rock interactions are being investigated by integrated structural, geochemical, metamorphic, fluid-inclusion, and thermochronologic studies.

In recognition of his expertise in geologic mapping, Prof. Reynolds was appointed by the U.S. Secretary of the Interior to the National Geologic Mapping Advisory Committee. He has also been President of the Arizona Geological Society and has served on various other National and local committees.

Teaching and Science-Education Research

At Arizona State University, Professor Reynolds teaches various courses, including Advanced Field Geology, Advanced Structural Geology, Geotectonics, Orogenic Systems, Cordilleran Regional Geology, Introductory Geology, Introduction to Geology in the Field, and Summer Field Geology. He is widely regarded as one of the best, most energetic and fun, teachers in the geology department. He known for his innovative teaching methods, has received the departmental "best teacher" award three times, and has been nominated for other university teaching awards.

He is a co-Principal Investigator of ACEPT (Arizona Collaboration for Excellence in the Preparation of Teachers), a major NSF-funded science education reform movement being coordinated at ASU. As part of this program, Steve and his colleages are reforming the introductory geology classes at ASU and other ACEPT-participating schools, with the goal of incorporating more hands-on, active learning, critical inquiry, scientific reasoning, and multimedia. Steve also has an active science-outreach program, including giving talks at teacher workshops, appearing on PBS specials, and narrating geologic videos for the new Arizona Science Center. Typical Student-Evaluation Comments: "Cool dude" / "My favorite class at Arizona State University; I never thought in my wildest dreams that I would enjoy a science class" / "Fantastic instructor"/ "He made the class fun and you can tell he loves geology" / "Instructor is great -- his joy of geology is spreading to the class" / "Best instructor I’ve had in college" / "I love this guy -- I hate science but Dr. Reynolds made this my favorite class" / "I’ve never had a teacher who loved his job as much and took time to meet his students" / "Best class I have ever taken"


Recent Professional Experience