Abstract / Description of output
Micro-tomographic images of rocks provide new ways of characterizing microstructure and help to lay foundations for computational multiscale geosciences. This paper presents an analysis of percolation and anisotropic permeability of a mylonite sample from the Redbank shear zone, Australiadeformed under upper-greenschistfacies metamorphic conditions in the middle of the crust. The mylonite sample has been scanned by high-resolution synchrotron radiation in a series of sub-samples. We use extended local porosity theory and the moving window method to conduct a stochastic analysis. Scale dependent characteristics of porosity, percolation and anisotropy of permeability are derived. Two sub-samples are analyzed in detail and different features are extracted and visualized. The sub-sample in the lowstrain margin of the shear zone is characterized by random and irregular distributed cavities along grain boundaries. These cavities are not percolating on the sub-sample scale.However the sub-sample in the centre of the shear zone exhibits percolating pore space around the synmylonitically reacting feldspar clasts. Our analysis is a first step towards an understanding of micro-scale fluid percolation in mid-crustal shear zones.
Original language | English |
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Title of host publication | Advances in Geosciences |
Subtitle of host publication | Volume 20: Solid Earth (SE) |
Publisher | World Scientific |
Pages | 229-246 |
Number of pages | 18 |
ISBN (Electronic) | 9789812838186 |
ISBN (Print) | 9812838171, 9789812838179 |
DOIs | |
Publication status | Published - 1 Jan 2010 |