Crustal Melting and Orogeny

Gneiss domes, metamorphic core complexes, and orogenic plateaux

 

 

For many years, members of the STAMP group have investigated the mechanisms, magnitudes, and consequences of the flow of partially molten crust. We use field and modeling approaches to understand the transfer of heat and material laterally (in orogenic plateaux) and vertically (in gneiss domes and metamorphic core complexes).
 

Figure 1. Outcrop photograph of migmatite in the core of the Naxos dome (Aegean Sea, Greece)

 

We have focused on migmatite-cored domes (Figure 1) in particular because these are ubiquitous features in most orogens and, in many orogens, are the sites of maximum exhumation of deep crustal rocks. In our studies of gneiss domes, we have tried to answer questions such as:

- What are the internal dynamics of domes? That is, how did the partially molten crust flow in the domes during their ascent and emplacement? We have used field and geophysical methods as well as numerical modeling to address this question, and have identified “double domes” as a common mode of dome formation in extension (Figures 2, 3).

 

 

  

Figure 2. Example 2D model showing formation of a “double dome”. Extension of the brittle upper crust drives convergent lateral flow in the deep crust followed by vertical ascent under the normal fault in the upper crust. The flowing partially molten crust may then ‘turn over’ and flow to either side of the median zone, in separate subdomes.

(from Rey et al., 2011)

 

 

- How do dome rocks relate (structurally, thermally) to their overlying metamorphic rocks and structures (which in many cases are detachment faults of metamorphic core complexes) (Figure 3)? This work involves determining the pressure-temperature-time-deformation history of dome and overlying rocks.

 

Figure 3. Schematic cross section of the Thor-Odin dome in the Shuswap metamorphic core complex, British Columbia. 

The dome is located in the footwall of the low-angle normal fault (detachment)  on the eastern side of the core complex.

(from Rey et al., 2009, after Vanderhaeghe and Teyssier 1997)

 

- What is the role of oblique extension in dome formation and evolution? Many domes are highly elongate and occur in zones of transtension (Figure 4).

 

Figure 4. Schematic geologic maps of elongate “double” migmatite domes in metamorphic core complexes:

Naxos (Greece) and the Montagne Noire (France). (modified from Rey et al., 2011)

 

 

This research is supported by an NSF grant to Teyssier and Whitney.

 

People: Christian Teyssier, Donna Whitney, Patrice Rey (U Sydney), Bénédicte Cenki-Tok (Montpellier), Francoise Roger (Montpellier), Jennifer Wright (MS 2013), Stacia Gordon (PhD 2009; U of Nevada-Reno), Seth Kruckenberg (PhD 2009; Boston College), Rory McFadden (PhD 2009; Salem State University)

 

 

Selected papers on this topic

 

Whitney, D.L., Teyssier, C., Rey, P.F., and Buck, W.R. (2013) Continental and oceanic core complexes. Geological Society of America Bulletin, 125, 273-298. doi: 10.1130/B30754.1

 

Kruckenberg, S.C., Vanderhaeghe, O., Ferré, E.C., Teyssier, C., and Whitney, D.L. (2011) Flow of partially molten crust and the internal dynamics of a migmatite dome, Naxos, Greece. Tectonics, TC3001. doi: 10.1029.2010TC002751.

 

Rey, P.F., Teyssier, C., Kruckenberg, S.C., and Whitney, D.L. (2011) Viscous collision in channel explains double domes in metamorphic core complexes. Geology, 39 (4), 387-390.

 

Rey, P.F., Teyssier, C., and Whitney, D.L. (2010) The limit of channel flow in orogenic plateaux. Lithosphere, 2, 328-332. doi: 10.1130/L114.1

 

Kruckenberg, S., Ferré, E., Teyssier, C., Vanderhaeghe, O., Whitney, D.L., Seaton, N.C.A., and Skord, J. (2010) Viscoplastic flow in migmatites deduced from fabric anisotropy: An example from the Naxos dome, Greece. Journal of Geophysical Research, 115, B09401. Doi: 1029/2009JB007012.

 

McFadden, R.R., Teyssier, C., Siddoway, C., Whitney, D.L., and Fanning, C.M. (2010) Oblique dilation, melt transfer, and gneiss dome emplacement. Geology, 38, 375-378.

 

Rey, P., Teyssier, C., and Whitney, D.L. (2009) The role of partial melting and extensional strain rates in the development of metamorphic core complexes (McMCC). Tectonophysics, 477 (3-4), 135-144.

 

Rey, P., Teyssier, C., and Whitney, D.L. (2009) Crustal melting and core complex dynamics. Geology, 37 (5), 391-394.

 

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, C.M., and Dunlap, W.J. (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., Teyssier, C., and Heizler, M.T. (2007) Gneiss domes, metamorphic core complexes, and wrench zones: Thermal and structural evolution of the Niğde 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, 39-64.

 

Whitney, D.L., Teyssier, C., and Vanderhaeghe, O. (2004) Gneiss domes and crustal flow. In: Whitney, D.L., Teyssier, C., and Siddoway, C.S. (eds.), Gneiss Domes and 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 and Orogeny, Geological Society of America Special Paper 380, 129-139.

 

Whitney, D.L., Paterson, S.R., Schmidt, K.L., Glazner, A.F., and Kopf, C. (2004) Growth and demise of continental arcs and orogenic plateaux in the North American Cordillera: from Baja to British Columbia. 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, 167-176.

 

Teyssier, C., and Whitney, D.L. (2002) Gneiss domes and orogeny. Geology, 30, 1139-1142.