Conjugate, or bimodal, fault patterns dominate the geological literature on shear failure. Based on Anderson's (1905) application of the Mohr-Coulomb failure criterion, these patterns have been interpreted from all tectonic regimes, including normal, strike-slip and thrust (reverse) faulting. However, a fundamental limitation of the Mohr-Coulomb failure criterion e and others that assume faults...

[1] A general theory for transitions between sub-Rayleigh and intersonic rupture speeds is developed for faults governed by slip-weakening friction. The transition occurs when stresses moving at intersonic speeds ahead of expanding or accelerating sub-Rayleigh ruptures exceed the peak strength of the fault, initiating slip within a daughter crack. Upon reaching a critical nucleation length, the...

the most enigmatic problems with the nearly 200 salt domes pierced in the persian gulf and in the zagros mountain ranges (zmr) in southern iran, a unique morphology in the world, have been the matter of this study, which is based on a combination of field work, enhancement of satellite and aerial photographs etc. in the zmr, structural anomalies are frequently associated with similar facies dis...

Seismic hazard assessment of strike-slip faults is based partly on the identification and mapping of landforms laterally offset due to fault activity. The characterization of these features affected by slow-moving faults is challenging relative to studies emphasizing rapidly slipping faults. We propose a methodology for scoring fault offsets based on subjective and objective qualities. We apply...

Many estimates of seismic risk depend crucially on how well the date of faulting events can be determined from the stratigraphic position of fault strands exposed in exploratory trenches. However, fault strands cut by trenches may seem to die out where they are in fact only poorly expressed, or they may actually die out. Such ambiguity can lead to misinterpretation of the time of the most recen...

Compressive and extensive horsetails are common structures on the lateral termination of brittle strike-slip faults, which forms within the shallow continental crust. Here we report another possibility, the lateral termination of a brittle strike-slip fault in a formation-parallel low-temperature ductile shear zone within sulphatic, gypsum-dominated evaporites. In the Southern Alps, over a dist...

Unfaulting seismic images to correlate seismic reflectors across faults is helpful in seismic interpretation, and is useful for seismic horizon extraction. Methods for unfaulting typically assume that fault geometries need not change during unfaulting. However, for seismic images containing multiple faults and, especially, intersecting faults, this assumption often results in unnecessary distor...

Observations demonstrate that faults are fractal surfaces with deviations from planarity at all scales. We study dynamic rupture propagation on self-similar faults having root mean square (rms) height fluctuations of order 10 3 to 10 2 times the profile length. Our 2D plane strain models feature strongly rate-weakening fault friction and off-fault Drucker–Prager viscoplasticity. The latter boun...

A large fraction of major intracontinental strike-slip faults, defi ned here as those slipping at rates of ~10 mm/yr or more, lie adjacent to relatively strong regions, such as oceanic lithosphere or Precambrian shields. We suggest that such faults form adjacent to discontinuities in strength, because strain in a continuous medium must concentrate near such strong objects. Concentration in stra...

Compilation of almost 200 new maximum horizontal stress (SHmax) orientations in Texas reveals a complex intraplate stress field. A large extensional stress province is associated with extensive growth faulting from northeastern Mexico to Louisiana. SHmax is subparallel to the coastline, following the strikes of the growth faults. In contrast, we observe a strike-slip/normal faulting regime with...