For both quartz and calcite rocks we have studied various aspects of the intracrystalline plastic and grain size sensitive flow of calcite rocks, both natural and prepared from powders by hot isostatic pressing. Mechanisms of dynamic recrystallization and flow localization into shear zones have been observed for calcite rocks. For quartz rocks we have induced plastic flow at 300 MPa confining pressure following incorporation of water during grain growth. Grain size sensitive flow has been produced in ultrafine grained quartz rocks by Ernie Rutter and Kate Brodie using the Paterson Gas Medium testing machine and microstructures have been studied using orientation contrast using SEM facilities both in Earth Sceinces and in the Materials Science Centre.
Julian Mecklenburgh is looking at changes in permeability and electrical conductivity of marbles during high-temperature plastic flow.
- Rutter, E. H. and Brodie, K. H. 2004. Experimental intracrystalline plastic flow in hot-pressed synthetic quartzite prepared from Brazilian quartz crystals. Journal of Structural Geology 26(2), 259-270.
- Rutter, E. H. & Brodie, K. H. 2004. Experimental grain size-sensitive flow of hot-pressed Brazilian quartz aggregates. Journal of Structural Geology 26(11), 2011-2023.
- Covey-Crump, S. J. 2001. Variation of the exponential and power law creep parameters with strain for Carrara marble deformed at 120 degrees to 400 degrees C. Geophysical Research Letters 28(12), 2301-2304.
- Mecklenburgh, J. & Heidelbach, F. in prep. Electrical Conductivity of Carrara Marble During Dynamic-Recrystallisation. Journal of Geophysical Research.
Through high pressure and temperature experiments on isostructural analogs of mantle phase we have gained insight on the flow behaviour and the resulting seimic of mantle minerals.
- Mecklenburgh, J., Zhao, Y. H., Heidelbach, F. & Mackwell, S. 2006. Deformation of Olivine-Spinel Aggregates in the System (Mg,Ni)2GeO4 Deformed to High-Strain in Torsion: Implications for Upper Mantle Anisotropy. Journal of Geophysical Research 111(B11209), doi:10.1029/2006JB004285.
For more information contact: Julian Mecklenburgh
The deformation behaviour of partially molten granite and the role of tectonism in the extraction of granitic melt from its protolith are key questions in tectonics. In order to try to circumvent some of the problems of working with partially molten "real" rocks, we have fabricated a synthetic analogue using quartz as the solid phase and a eutectoid melt phase prepared from oxides (Ernie Rutter, Duncan Irving and Julian Mecklenburgh). Parallel field studies of progressive melting in the aureole of the Etive granite (W. Scotland) are also being made (Giles Droop, Kate Brodie, Duncan Irving).
- Rutter, E. H., Brodie, K. H. & Irving, D. H. 2006. Flow of synthetic, wet, partially molten granite under undrained conditions: An experimental study. Journal of Geophysical Research 111(B06407), doi:10.1029/2005JB004257.
- Mecklenburgh, J. & Rutter, E. H. 2003. On the rheology of partially molten synthetic granite. Journal of Structural Geology 25, 1575-1585.
This study is aimed at investigating high temperature linear viscous flow in mica, discovered by recent graduate Betty Mariani in her PhD research, and which has implications for the strength of mudstones undergoing crustal deformation and metamorphism and for mid-crustal fault zones.
- Mariani, E, Brodie, K.H. and Rutter, E.H. 2006. Experimental deformation of muscovite shear zones at high temperatures under hydrothermal conditions and the strength of phyllosilicate-bearing faults in nature. J. Struct. Geol. 28(9), 1569-1587.
The dehydration reaction serpentinite to olivine + talc + water is particularly well suited to experimental study. Experiments have been carried out to measure the volume changes produced by reaction (porosity creation) and to evaluate their effect on the strength and ductility of the rock (Chris Arkwright, Ernie Rutter, Kate Brodie and Sergio Llana-Funez (now at University of Liverpool)).
Deformation/metamorphism relations during the natural deformation of basic rocks are also being studied by Anna Thurston (supervised by Kate Brodie and Giles Droop), with sample materials from Scotland and the western Alps.