Structural Geology and Tectonics

The program in Structural Geology and Tectonics encompasses a wide variety of subjects, and a wide variety of areas all over the world. The common themes of our research are to understand the deformation of the Earth's crust and to reconstruct its history through geologic time. We approach these studies from many different perspectives, including global synthesis, field studies, materials science, theoretical analysis, and numerical modeling. Research in this group overlaps extensively with geophysics, igneous petrology, and metamorphic petrology, and there is productive interaction with faculty in these other areas.


Magali BillenMagali Billen
Professor | 530-752-4169

Geophysics; subduction zone dynamics; deformation and rheology of the lithosphere and upper mantle; effects of water and melt on viscosity; plate tectonics. Recent projects include the effect of overriding plate structure on slab dip, rifting of volcanic arcs, time-dependent thermal structure of the slab and mantle wedge, effect of phase transitions on slab deformation, subduction of oceanic plateaus, and the relationship between the stress-state in slabs and deep earthquakes.

Eric CowgillEric Cowgill
Professor | 530-754-6574

Structural geology and tectonics; primarily interested in understanding regional deformation within active continental collision zones. Emphasis on the evolution of orogen-scale fault systems and their interactions. Current projects include determining the regional kinematics of active deformation within the Arabia-Eurasia collision zone and the tectonic evolution of the northern Tibetan Plateau.

Louise KelloggLouise Kellogg
Distinguished Professor | 530-752-3690

In memoriam | 1959-2019

The solid Earth is in a continual state of deformation both in the deep interior as well as at its surface. Professor Kellogg is interested in both why and how this deformation occurs. She uses computer modeling of the thermal and chemical evolution of the Earth to understand the both the interior and surface evolution of the Earth, the pathways for carbon through Earth’s interior, and to model deformation in the crust associated with earthquakes. Her research group has combined geodetic measurements with numerical modeling of deformation in the crust and statistical analysis of seismicity to understand how faults behave.

Mike OskinMichael Oskin
Professor | 530-752-3993

As a structural geologist and geomorphologist, Oskin specialize in active crustal deformation and its relationships to surface processes and topography. His research program addresses three themes: 1. Quantifying variation of deformation rates and their relationship to earthquakes; 2. Constraining the forces and processes that govern continental deformation; 3. Predicting topographic responses to the growth of geologic structures. These themes build toward a common framework for understanding active crustal deformation and its expression in landscapes. The first two research themes differ largely by time scale, with the first focused on short-term deformation processes over one or more earthquake cycles, and the second concerned with longer-term accumulated deformation and time-averaged processes. The third theme includes the development of new tools to quantify deformation from topography. I also pursue the inverse problem of quantifying surface processes from geomorphic responses to crustal deformation.

Nicholas PinterNicholas Pinter
Professor | 530-754-1041

Pinter's research focuses on earth-surface processes (geomorphology) applied to a broad range of problems. Much recent work involves rivers, fluvial geomorphology, flood hydrology, floodplains, and watersheds. His research group applies fluvial geomorphology, hydrologic and statistical tools, hydraulic modeling, and other approaches to assess river dynamics and flood hazards. Although much current research focuses on rivers, he continues to work on a broad range of processes that shape the earth surface and operate.

Faculty Emeriti

Cathy BusbyCathy J. Busby
Professor Emerita

Busby's 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.

John DeweyJohn F. Dewey
Distinguished Professor Emeritus
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. Derivative interests are in the geohazard of volcanoes, earthquakes and landslides.

Sarah RoeskeSarah M. Roeske
Research Geologist Emerita | 530-752-4933

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.

Rob TwissRobert J. Twiss
Professor Emeritus

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.

Scientists & Academic Federation Members

Donna Eberhart-PhillipsDonna Eberhart-Phillips
Research Scientist
2209A Earth & Physical Sci | 530-752-1402

John NaliboffJohn Naliboff
Assistant Project Scientist
1227 Mathematical Sciences

M. Burak YikilmazM. Burak Yikilmaz
Assistant Research Scientist