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...

This study focuses on determining the orientation and constraining magnitude of present-day stresses in Dezful Embayment Iran’s Zagros Fold Thrust Belt. Two datasets are used: first includes petrophysical data from 25 wells (3 to 4 km deep), second contains 108 earthquake focal mechanisms, mostly occurring blind active basement faults (5 20 deep). Formal stress inversion analysis mechanisms dem...

The Carboneras fault is one of three principal Cenozoic strike-slip faults in the Betic Cordillera of southeastern Spain. In this study, we characterize the paleoseismic history of the Carboneras fault by examining the evidence for lateral offset of 85-180 ka ‘Iyrrhenian marine terraces, by dating the left-lateral stream-channel offsets in La Serrata, and by postulating a late Holocene coastal ...

First order splay faults, as defined here, are secondary faults that form at acute angles symmetrically on either side of a primary fault of the same sense of shear. We show that these faults form when the primary fault becomes critically misaligned with the principal stresses such that splay fault formation, on the optimum plane for faulting, is favored. First order splay faults, in distinctio...

[1] Several large strike slip earthquakes have occurred in various tectonic settings in the past 5 years, adding well documented data to the global collection of moment and length estimates for such earthquakes. Based on this augmented dataset, we reexamine the controversial issue of scaling of seismic moment with length of rupture. We find that the global dataset of large strike-slip earthquak...

[1] We develop a two-dimensional boundary element earthquake cycle model including deep interseismic creep on vertical strike-slip faults in an elastic lithosphere coupled to a viscoelastic asthenosphere. Uniform slip on the upper part of the fault is prescribed periodically to represent great strike-slip earthquakes. Below the coseismic rupture the fault creeps in response to lithospheric shea...

We study how the fault dip and slip rake angles affect near-source ground velocities and displacements as faulting transitions from strike-slip motion on a vertical fault to thrust motion on a shallow-dipping fault. Ground motions are computed for five fault geometries with different combinations of fault dip and rake angles and common values for the fault area and the average slip. The nature ...

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...

The southern San Jacinto fault zone is characterized by high seismicity and a complex fault pattern that offers an excellent setting for investigating interactions between distinct fatfits. This fault zone is roughly outlined by two subparallel master fault strands, the Coyote Creek and Clark-San Felipe Hills faults, that are located 2 to 10 km apart and are intersected by a series of secondary...

introduction two main principal aspects for the genesis of porphyry copper deposits have been determined. the first genetic model concerns the petrologic and geochemical processes and the other relates the genesis to crustal deformation and geodynamic conditions (kesler, 1997). recent studies (e.g., padilla garza et al., 2001) show that the generation and emplacement of porphyry copper deposits...