Structure & Tectonics
Tectonics relates to the broad architecture of the outer part of the earth, that is, the major structural or deformational features and their relations, origin, and historical evolution*. It is closely related to structural geology, but tectonics generally deals with continental to planetary scale features such as mountain belts, oceanic and continental plates, their boundaries, and the dynamics of their interactions. Essentially, any field that helps us understand how the lithosphere evolves and behaves may be considered ‘tectonics’. Structural geology deals more with map-, outcrop-, hand sample-, and micro-scale spatial relationships of rock fabrics, faults, and folds. The methods of structural geology are used to deduce the larger scale aspects of the lithosphere.
A group of faculty in the Department of Earth and Environmental Sciences at UK investigate a spectrum of processes that further our understanding of the tectonic evolution of the lithosphere.
Professor Frank Ettensohn relates the stratigraphy, sedimentology, and paleontology of the Appalachian foreland basin and U.S. mid-continent platform to the dynamics of mountain belts and relatively stable continental interiors.
Professor Dave Moecher employs geochemistry, petrology, bedrock mapping, and structural geology in understanding the behavior of rocks in ductile and brittle fault zones that bound blocks of continental crust in mountain belts.
In addition to these methods, Professor Dave Moecher uses geochronology as applied to crystalline rocks in the roots of mountain belts to understand deep crustal deformation, which can ultimately be related to the relatively shallow crustal processes.
All such studies require a component of field work; projects are currently underway in the Appalachian orogen in the southeastern and northeastern U.S., Grenville orogen of southern Canada, Andean orogen in Argentina, Cordilleran orogen of western North America, and the eastern U.S. mid-continent.
An emerging field of tectonics is termed “Neotectonics” and deals with active crustal deformation process. Professor Ed Woolery uses geophysical methods such as shallow reflection seismology to investigate the behavior of the New Madrid Seismic zone of the U.S. mid-continent area.
Professor Sean Bemis uses the tools of structural geology, Quaternary stratigraphy, and geomorphology to investigate the processes of active deformation of the Earth's crust. Quaternary dating methods, such as radiocarbon dating, terrestrial cosmogenic nuclide exposure dating, and tephrachronology, provide the ability to date landforms and surficial deposits. When combined with high-resolution topography/surveying, paleoseismic trenching, and geologic mapping, we can define slip rates for faults, develop prehistoric earthquake chronologies, and infer potential earthquake magnitudes. These efforts contribute to our understanding of seismic hazards, earthquake recurrence models, and processes of fault interaction and mountain belt growth.
*see McGill's EPS page for glossary of geologic terms