Research

General Interests My primary research interests lie in the structural and tectonic evolution of continental crust in ancient collisional mountain systems, particularly the Appalachian-Caledonian chain, and how these systems were modified by subsequent extensional collapse. Conceptually, my work addresses a fundamental question of plate tectonics - why do ocean basins tend to open along old mountain belts? I maintain active research programs in the southernmost Appalachians, U.S.A., and in the northernmost Caledonides in arctic Norway. I emphasize field-based investigations integrated with laboratory studies including, geometric and kinematic structural analysis, petrofabrics, metamorphic petrology, and 40Ar/39Ar thermochronology. Consequently, my research and that of my students requires backgrounds and depth in several diverse disciplines of geology, including geochemistry, geophysics, and petrology. Ours is a terminal M.S. degree program; I have a deep commitment and derive great satisfaction from the close supervision of my M.S. students.

I'm proud of the efforts of my M.S. students and below list a sampling of their accomplishments.

Active Research Projects Arctic Norway. I have been active in structural and tectonic studies of the Scandinavian Caledonides, the northern counterpart to the Appalachian system, ever since doing my M.S. thesis in north Norway in 1979. My students and I have worked collaboratively with colleagues at the University of Oslo and the University of Tromsö. In my 10 years at Auburn, I've supported 11 students doing field projects in Norway. Generally speaking, these projects are regional tectonic syntheses that emphasize some particular aspect of tectonic development. Emphasis has evolved from studies of contractional evolution of the stack of far-traveled allochthons (nappes or thrust sheets), to terrane analyses of the allochthons, to contractional and extensional modification of the nappe stack, and currently to the extensional evolution of the north Norwegian margin. This work has been supported by the NSF (with Dr. Willis Hames, also at Auburn), NATO, the ACS-PRF, and the Norwegian Marshall Foundation. Presently, I am most excited about our work on the extensional evolution of the Norwegian margin.

Dr. Hames and I are wrapping up our two-year NSF project in the Lofoten islands, which combined field/structural studies with 40Ar/39Ar laser analyses to evaluate the extensional evolution of the margin in that region. My interests now are to connect our findings from Lofoten to the geology of the mainland, across Vestfjord. I presently have support from the Norwegian Petroleum Industry to maintain my Norwegian research program for the next 5 years and I am looking for good M.S. students to participate.

Southern Appalachians. Most of my work in the southern Appalachians has focused on the tectonic evolution of the crystalline rocks of the Piedmont. Auburn lies within the Pine Mountain terrane, which is the Appalachian's most southern and internal Grenville basement massif that retains its primary miogeoclinal cover. Although I am principally a "hard-rock" structural geologist, my research has taken me from the high-grade units of the Pine Mountain terrane to the low-grade cover rocks of the Talladega slate belt and finally to the nonmetamorphosed cover sequences preserved in the foreland fold and thrust belt. This work allows me to compare the structures and sequences of rocks from these diverse tectonic settings and to deduce their significance for Late Precambrian evolution and Paleozoic destruction of the Laurentian margin. Recently, I have obtained Department of Interior grants (USGS-EDMAP Program) to fund my M.S. students' mapping and structural analysis in rocks of the Piedmont, the slate belt, and the Valley and Ridge. These projects are in collaboration with workers at the Geological Survey of Alabama (USGS-STATEMAP Project)

and the USGS (in Atlanta, GA, and Denver, CO) and are aimed at characterizing small- and large-scale structures and synthesizing the geological history of rocksof the Choccolocco, Heflin, and Parkers Crossroads 7.5 USGS Quadrangles. These projects aid in delineating possible contamination of ground water, supplying data to planners coping with rapid urban expansion, and providing datato the Army to help in the closing of Fort McClellan, a chemical weapons repository near Anniston, AL.

Piceance basin, Colorado Presently, I am completing a Department of Energy funded project to help evaluate the origin of living, anaerobic bacteria recovered from a deep subsurface well (2 km deep) in the Piceance basin of western Colorado. My student, Robert Drake, and I are mapping and analyzing folds and faults and natural fractures in the Wasatch Formation to evaluate their effect on hydrologic flow models proposed for the basin.

An interesting aspect of this work involves our statistical analysis of the geometry and kinematics and formation of chaotic(?) fractures in shoestring sandstone bodies of the Eocene Wasatch Formation.