Cratons form the cores of continents and were formed within a narrow window of time (2.5–3.2 Gy ago), the majority having remained stable ever since. Petrologic evidence suggests that the thick mantle roots underlying cratons were built by underthrusting of oceanic and arc lithosphere, but paradoxically this requires that the building blocks of cratons are weak even though cratons must have bee...

The evolution of wide shear zones or shear bands was investigated experimentally and numerically for quasistatic dry granular flows in split bottom shear cells. We compare the behavior of materials consisting of beads, irregular grains, such as sand, and elongated particles. Shearing an initially random sample, the zone width was found to significantly decrease in the first stage of the process...

The Boulder-Lefroy shear zone, developed in the ca. 2.7 to 2.65 Ga Archean greenstone sequence of the Kalgoorlie terrane in the Yilgarn craton, is remarkable for the number and importance of gold deposits it hosts. These include, from south to north, the following gold districts (with tons of contained Au): St Ives (253 t), Hampton-Boulder-Jubilee (123 t), Golden Mile (1,821 t) plus Mount Charl...

The effects of nanosecond laser peening on Zr41Ti14Cu12.5Ni10Be22.5 metallic glass were investigated in this study. The peening treatment produced an extra-deep shock-affected zone compared to crystal metal. As opposed to the conventional shear bands, numerous arc shear bands appeared and aggregated in the vertical direction of the laser beam, forming basic units for accommodating plastic defor...

The objective of this paper is to investigate the viscous shear heating effect on the formation of minimum film thickness in inlet zone of the hydrostatic extrusion process as function of various operating parameters. Minimum film thicknesses in the inlet zone has been evaluated at various extrusion speeds, material parameters, extrusion pressures, and die semiangle for extrusion of low strengt...

We present some experimental and numerical results based on a simple model designed to give an estimate for the width of a shear zone. We conclude that the observed finite size of the shear zone can be associated with the propagation of the force lines inside the medium. The model, based on a simple argument on the force distribution and dilatancy, predicts a width of about ten grain diameters.

We conduct a two-dimensional numerical experiment on the lower crust under an intraplate strike-slip fault based on laboratory-derived power-law rheologies considering the effects of grain size and water. To understand the effects of far-field loading and material properties on the deformation of the lower crust on a geological time scale, we assume steady fault sliding on the fault in the uppe...

Strength reduction finite element method (SRFEM) has been widely used to analyze the slope stability. Strength Reduction Factor (SRF) is yielded as the slope Factor Of Safety (FOS) when a running-though shear failure zone comes into being, in which the Plastic Element EQuivalent strain (PEEQ) is employed as the judgment of shear failure initiation in this paper. Moreover, the filed variable is ...

We present data from the Josephine Peridotite (SW Oregon, USA) that constrain the underlying physical processes responsible for the initiation of shear localization and the evolution of ductile shear zones in Earth's mantle. Field measurements of narrow (2–60 m wide) ductile shear zones in harzburgite were used to construct strain profiles, which have maximum shear strains ranging from γ1⁄45.25...