Academic Personnel Emeriti
A first-generation college student, Professor Busby got her B.S. degree from UC Berkeley (1976), her Ph.D. at Princeton University (1983), and was a faculty member at UC Santa Barbara for 32 years. She raised three daughters, who all graduated from the University of California. Cathy moved to UC Davis in January 2015 as Professor Emerita and Research Scientist because the Earth and Planetary Sciences department has a high proportion of female faculty and is very supportive of women. Her current research is on late Cenozoic transtensional rift tectonics and volcanology of the Sierra Nevada/Walker Lane and the Gulf of California, as well as an accreted oceanic arc terrane in Baja California, with comparisons to modern oceanic arcs. Cathy’s research is based on detailed geologic mapping of volcanic terranes, supported by petrographic, geochemical, geochronological, paleomagnetic and mineral chemistry data. Busby Google Scholar
Professor Day’s research interests are in the broad field of igneous and metamorphic petrology and geochronology with significant emphasis on thermodynamics and phase equilibria and applications to understanding the evolution of orogenic belts. Most of his work has been in the Sierra Nevada of California but also includes contributions to the metamorphic petrology and geochronology of the California Coast Ranges, the New England Appalachians, and the Qinling and Tianshan orogenic belts of China. Continuing projects involve the structure and metamorphism of Mesozoic volcanic arc terranes in the Sierra Nevada foothills. Currently, he is studying the geochronology and petrology of high-grade exotic blocks in Franciscan mélange in the California Coastal Range. Day Google Scholar | ORCID
Basic interests and knowledge are in structural geology and tectonics from the small-scale materials science of deformed rocks to the large-scale origin of topography and structures. Ongoing field-based research is on the rock fabrics and structures of transpression and transtension especially in California, New Zealand, Norway, Ireland and Newfoundland. Evolving interests are in the neotectonics of California and Nevada in the relationship among faulting,topography, and sediment provenance, yield and distribution. Derivative interests are in the geohazard of volcanoes, earthquakes and landslides.
Professor Doyle's research deals primarily with the origin and early evolution of angiosperms. His oldest interest is in Cretaceous fossil pollen and leaves and their implications for the evolution, geographic spread, and original ecology of angiosperms. More recently his research has emphasized phylogenetic analyses of relationships between angiosperms and other seed plants and among living primitive angiosperm groups, based on morphological, molecular, and fossil evidence. Jim has worked on phylogeny, evolution, and biogeography of several living plant groups, especially the tropical family Annonaceae, the largest family of primitive angiosperms. His current main project aims to integrate Early Cretaceous fossils into the predominantly molecular phylogeny of living primitive angiosperms and to evaluate implications of the results for morphological evolution.
Experimental igneous petrology and geochemistry; phase equilibria and kinetics of silicate systems at elevated pressure and temperature; physical, transport and thermodynamic properties of silicate melts. Recent projects include (a) Laboratory: low to high pressure phase equilibria studies of basaltic systems; trace element partitioning; chemical and self diffusion studies of silicate melts; solution properties of silicate liquids from thermal diffusion. (b) Field: magmatic evolution of the North Atlantic Ocean basin and the evolution of the Iceland hot spot; petrologic studies of early Tertiary volcanic and plutonic rocks of East Greenland. UC Davis Interdisciplinary Center for Plasma Mass Spectrometry (UC Davis ICPMS)
Geophysics; mid- ocean ridge processes; structure of the oceanic crust; geophysical inverse theory; 3 dimensional structure of the oceanic crust. Recent projects include study of magma chambers under the East Pacific Rise; seismicity and dynamics of hydrothermal systems on the ridges and continental volcanoes; evolution of the oceanic crust; structures of seamounts and fracture zones.
Fluvial geomorphology, ecogeomorphology, river and water resource analysis. Research emphasis on the geomorphology and ecology of rivers and streams, their response to changes in land use/land cover and flow regulation, and their restoration and assessment. Projects include restoration of river floodplains, management of levee systems in floodplain/estuary systems, re-operation of hydropower systems to improve aquatic ecosystems and adapt to climate change, and restoration of spring fed streams and meadow systems. Outreach includes assisting agencies and non-profits in assessment and formulation of river management policies.
Her research relates microscopic features of structure and bonding to macroscopic thermodynamic behavior in minerals, ceramics, and other complex materials. She has published over 500 scientific papers.
Structural geology and metamorphic petrology. Combine detailed macrostructural analysis in the field with microstructural studies, metamorphic petrology, and geochronology, in order to solve tectonic problems. Current research topics include the tectonic evolution of convergent margins in Alaska and Argentina, with a focus on determining type, age and relative significance of different periods of fault movements. Related problems include uplift of high P/low T metamorphic rocks and role of strike-slip faults at convergent margins.
Interfacial and mineral surface geochemistry; mineralogy; mineral physics. Research is focused on computational chemical models of interfacial structure as well as surface charging, sorption, dissolution, and precipitation phenomena at oxide-water interfaces. Computational methods are also applied to problems in mineralogy and in aqueous and silicate melt geochemistry, including physics of hydrated minerals, ligand exchange and electron transfer reactions.
Professor Schiffman is a mineralogist and petrologist whose research interests are in the metamorphism of volcanic rocks in active and fossil hydrothermal systems in terrestrial and submarine settings. He recently coauthored a popular guide book entitled "Exploring the Berryessa Region: A Geology, Nature and History Tour".
Professor Spero's research focuses on the biological and environmental parameters that affect the stable isotope and trace element geochemistry of the shells of recent and fossil organisms through the application of state-of-the-art geochemical instrumentation. His research directly influences the interpretation of geochemical data from the fossil record and impacts the fields of Paleoclimatology, Marine Micropaleontology, and Paleoceanography. He collaborates with researchers in Europe and Asia to probe the fossil record using novel geochemical approaches with carbonate and silicate microfossils. He is a Fellow of the American Geophysical Union, Geological Society of America, American Association for the Advancement of Science and the California Academy of Science. Spero Google Scholar
Professor Turcotte has worked on a wide variety of problems in geodynamics. Many of these are included in his textbook (with Gerald Schubert) Geodynamics (3rd edition). He has also worked on a wide variety of applications of fractals and chaos to problems in geology and geophysics. Many of these are included in his textbook Fractals and Chaos in Geology and Geophysics (2nd edition). Don currently supervises graduate student research on induced seismicity and the distribution of carbon in the earth. He is a member of the National Academy of Sciences and the American Academy of Arts and Sciences.
Professor Twiss' general research interests include the mechanisms and mechanics of rock deformation and the interpretation of associated structures. His research involves the inference of rotational components of deformation from inversion of seismic first-motion data and fault-slip data, using micropolar continuum theory; and the use of fault systematics to infer large-scale brittle deformation. Earlier research interests include paleopiezometry, which is the use of the microstructures of ductilely deformed mineral grains to infer the paleostresses associated with deformation; and the systematics of fold geometry. Twiss co-authored the textbooks Structural Geology, 2nd Edition (Twiss and Moores, W.H. Freeman & Co., 2007) and Tectonics (Moores and Twiss; Waveland Press, 2014).
For much of his career, Ken Verosub has used the magnetic properties of rocks, sediments and soils to determine the behavior of the Earth's magnetic field, the ages of sedimentary sequences, the motions of tectonic plates, and the history of the Earth's climate during the past 40 million years. Recently he has become more generally interested in the influence of geologic processes on the development of societies, civilizations and cultures. In pursuit of this interest, he spent the 2009-2010 academic year as a senior science advisor for water and climate issues in the U.S. Department of State. In addition to on-going paleomagnetic and environmental magnetic studies, he is working on volcanic eruptions that have caused global cooling, seismic risk and subsidence problems in the Sacramento-San Joaquin Delta, the identification of deep groundwater aquifers and the determination of river flows directly from geospatial imagery.
Aqueous geochemistry; stable isotope geochemistry; economic geology. Research has focused on water/rock interaction in active and ancient hydrothermal systems, including the "black smokers" on the mid-ocean ridges. Research topics include the geology and geochemistry of sulfide deposits and hydrothermal alteration in seafloor hydrothermal systems and on-land analogs. Hydrothermal activity at sediment-covered portions of the northern Juan de Fuca Ridge and southern Gorda Ridge seafloor spreading centers have been a long term research interest, including participation in Legs 139 and 169 of the Ocean Drilling Program. The Iceland Deep Drilling Project is providing new opportunities to investigate water/rock interaction in the deep, high-temperature roots of hydrothermal systems. Other interests include the environmental effects of mining, particularly the generation of acid mine drainage, mercury contamination in Clear Lake related to the abandoned Sulphur Bank Hg mine, the geochemical and biological cycling of sulfur, and sulfur isotope geochemistry.