%0 Journal Article
%A Pérez López, Raúl
%A Paredes, Carlos
%A Muñoz Martín, Alfonso
%T Relationship between the fractal dimension anisotropy of the spatial faults distribution and the paleostress fields on a Variscan granitic massif (Central Spain): the F-parameter
%D 2005
%@ 0191-8141
%U https://hdl.handle.net/20.500.14352/52607
%X The spatial distribution of faults is usually described as a fractal set characterised by the fractal dimension. In this work, we have filteredfault patterns interpreted from digital elevation models, aerial photographs and field maps, by using structural geological parameters of thestress ellipsoid (stress tensor direction and stress ratio R0) and age of deformation. From these filtered structural maps, we have obtained thefractal dimension associated with the fracture patterns developed during Permo-Triassic and Alpine tectonic events on a Variscan graniticmassif located in the Spanish Central System. Oriented fractal dimensions were calculated on several transects crossing the fault-filteredmaps. The fractal dimension (D), calculated by 1-D box-counting, describes an ellipse on a polar plot with the short axis as the minimumvalue (DHmin) and the long axis as the maximum value (DHmax) of the fractal dimensions measured. From these analyses, we have defined theF-parameter as a function of the maximum value, minimum value and vertical value of fractal dimension (Dz), FZ(DzKDHmin)/(DHmaxKDHmin). Finally we have established, from a local scale analysis, a perpendicular relationship between the principal axes of the ellipse of thefractal spatial anisotropy of fractures and the principal axes of the stress tensor (sHmax, sHmin and sz) that generates this dynamic pattern offractures. Furthermore, the F-parameter and the stress ratio R0 are equivalents and, applied in this area, both show a triaxial extension.
%~