RT Journal Article
T1 Geological, geophysical and geochemical structureof a fault zone developed in granitic rocks: Implicationsfor fault zone modeling in 3-D
A1 Escuder Viruete, J.
A1 Carbonell Beltrán, Ramón
A1 Pérez-Soba Aguilar, Cecilia María
A1 Martí, D.
A1 Pérez Estaún, A.
AB The structure of a fault zone developed ingranitic rocks can be established on the basis of the spatialvariability of geological, geophysical and geochemicalparameters. In the North Fault of the Mina Ratones area(SW Iberian Massif, Spain), fault rocks along two studiedtraverses (SR-2 and SR-3 boreholes) exhibit systematicchanges in mineralogy, geochemistry, fabrics and microstructuresthat are related to brittle deformation andalteration of granite to form cataclasite and subsequentgouge. The spatial distribution and intensity of thesechanges suggest a North Fault morphology that isconsistent with the fault-core/damage-zone model proposedby Chester et al. (1993) to describe a fault zonearchitecture. North Fault damage zone thickness can bedefined by the development of mechanically relatedmesoscopic faults and joints, that produce a FractureIndex (FI)>10. High FI values are spatially correlatedwith relative low seismic velocity zones (VP<5 km/s andVS<2.5 km/s in the well-logs), more probably related to ahigh concentration of fractures and geochemical alterationproduced by meteoric water-granite interaction alongfault surfaces. This correlation is the base of a geostatisticalmodel proposed in the final part of this study toimage the fault zone architecture of a granitic massif.
PB Springer Science Business Media
SN 1437-3254
YR 2004
FD 2004
LK https://hdl.handle.net/20.500.14352/50208
UL https://hdl.handle.net/20.500.14352/50208
LA eng
DS Docta Complutense
RD 16 abr 2025