This research involves investigation of the role of partial melting in the tectonic development of orogens, including continental arcs and collisional belts. Of particular interest is understanding the thermal and structural record of flow of partially molten crust in the context of the orogenic collapse. First order structures involving migmatites in most orogens worldwide are gneiss domes and core complexes. We use a variety of methods for determining the flow trajectories (kinematics), timing, and pressure-temperature-deformation conditions of crustal flow, including field work, microstructural analysis (petrographic and electron backscattered diffraction), thermobarometry, and geo-thermochronometry.
LEFT: View of the eastern margin of the Naxos gneiss dome (Greece), from the migmatite core (left) to the overlying marble and schist. RIGHT: Migmatites in the Okanogan dome of the Okanogan-Kettle core complex, Washington USA.
We are investigating the relationships and feedbacks of decompression, partial melting, and extensions, with a focus on migmatites in metamorphic core complexes. Migmatites are commonly found in domal structures, and migmatization and flow of partially molten crust are fundamental processes in the dynamics of doming. In addition, metamorphic pressure-temperature-time paths in migmatite-cored gneiss domes are typically characterized by isothermal decompression, suggesting that vertical flow of partially molten crust occurs rapidly during extension. This leads to questions about rates and mechanisms of decompression and the thermal and structural consequences of doming. Modeling work in conjunction with our field-based studies are in collaboration with Patrice Rey (Univ of Sydney).
List of gneiss domes and core complexes we are currently studying
Gneiss Domes and Crustal Flow Publications (2002-present)
Rey, P., Teyssier, C., and Whitney, D.L. (in press) Crustal melting and core complex dynamics. Geology.Rey, P., Teyssier, C., and Whitney, D.L. (in press) The role of partial melting and extensional strain rates in the development of metamorphic core complexes (McMCC). Tectonophysics.
Gordon, S.M., Whitney, D.L., Teyssier, C., Grove, M., and Dunlap, W.J. (2008) Timescales of migmatization, melt crystallization, and cooling in a Cordilleran gneiss dome, the Valhalla Complex, southeastern British Columbia. Tectonics, 27, TC4010, doi:10.1029/2007TC002103
Kruckenberg, S.C., Whitney, D.L., Teyssier, C., Fanning, M., and Dunlap, J.W. (2008) Paleocene-Eocene migmatite crystallization, extension, and exhumation in the hinterland of the northern Cordillera: Okanogan dome, Washington, USA. Geological Society of America Bulletin. 120, 912-929. doi; 10.1130/B26153.1
Whitney, D. L., C. Teyssier, and M. T. Heizler (2007) Gneiss domes, metamorphic core complexes, and wrench zones: Thermal and structural evolution of the Nigde Massif, central Anatolia. Tectonics, 26, TC5002, doi:10.1029/2006TC002040.
Teyssier, C., Ferré, E., Whitney, D.L., Norlander, B., Vanderhaeghe, O., and Parkinson, D. (2005) Flow of partially molten crust and origin of detachments during collapse of the Cordilleran orogen. In: Bruhn, D., and Burlini, L. (eds.), High-strain zones: structure and physical properties. Geological Society of London Special Publication 245.
Whitney, D.L., Teyssier, C., and Fayon, A.K. (2004) Isothermal decompression, partial melting, and the exhumation of deep continental crust. In: Grocott, J., Tikoff, B., McCaffrey, K.J.W., and Taylor, G. (eds.), Vertical Coupling and Decoupling in the Lithosphere, Geological Society of London Special Publication 227, 313-326.
Whitney, D.L., Teyssier, C., and Vanderhaegh, O. (2004) Gneiss domes and crustal flow. In: Whitney, D.L., Teyssier, C., and Siddoway, C.S. (eds.), Gneiss Domes in Orogeny, Geological Society of America Special Paper 380, 15-33.
Fayon, A.K., Whitney, D.L., and Teyssier, C. (2004) Exhumation of orogenic crust: diapiric ascent vs. low-angle normal faulting. In: Whitney, D.L., Teyssier, C., and Siddoway, C.S. (eds.), Gneiss Domes in Orogeny, Geological Society of America Special Paper 380, 129-139.
Norlander, B.H., Whitney, D.L., Teyssier, C., and Vanderhaeghe, O. (2002) High temperature decompression of the Shuswap metamorphic core complex, Canadian Cordillera. Lithos, 61, 103-125.
Teyssier, C., and Whitney, D.L. (2002) Gneiss domes and orogeny. Geology 30, 1139-1142.
Stacia Gordon (Ph.D., 2009), Lindsay J. Iredale (M.S., 2005), Barbara Francis (M.S. 2004), Britt H. Norlander (Ph.D. 2004)
Ongoing graduate research at Minnesota
Seth Kruckenberg, Rory McFadden