Damage zone and slip-surface evolution over μm to km scales in high-porosity Navajo sandstone, Utah

TL;DR: A comprehensive nomenclature that accounts for joints, faults, fractures, anticracks, shear zones, and deformation bands in compact and high-porosity rocks is presented in this paper.

TL;DR: In this paper, the authors show that reaction softening promotes the replacement of strong minerals with phyllosilicates, and that this weakening originates at the grain-scale and is transmitted to the entire fault zone via the interconnectivity of the phylloshilicate-rich zones resulting in a friction as low as 0.1 μ 0.3.

TL;DR: In this paper, the authors document the formation and evolution of the damage zones associated with strikeslip faults in porous sandstone, through detailed field and statistical studies of faults of increasing slip magnitudes.

TL;DR: The concept of fault facies as mentioned in this paper is a novel approach to fault description adapted to three-dimensional reservoir modeling purposes, where faults are considered strained volumes of rock, defining a threedimensional fault envelope in which host-rock structures and petrophysical properties are altered by tectonic deformation.

TL;DR: In this article, the internal structure of the San Gabriel fault and the Punchbowl fault are combined with previous characterizations of the SGF and PF to evaluate possible explanations for the low frictional strength and seismic characteristics.

TL;DR: In this article, the authors investigated the inelastic and failure behavior of six sandstones with porosities ranging from 15% to 35% and used a broad range of effective pressures to investigate the transition in failure mode from brittle faulting to cataclastic flow.

TL;DR: In this article, the authors quantified fault zone permeability in outcrop by detailed geologic mapping and by measurements using a minipermeameter, and found that deformation bands have porosity about one order of magnitude less than the surrounding host rock.

TL;DR: In this paper, a plane strain model for a fault is presented that takes into account the inelastic deformation involved in fault growth, and the model requires that the stresses at the tip of the fault never exceed the shear strength of the surrounding rock.