Dynamics of fault creep

Dynamics of fault creep

GEOMECHANICS ABSTRACTS block thickness changes with depth. This disadvantage is offset by allowing a unique solution for depth to the basal detachmen...

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GEOMECHANICS ABSTRACTS

block thickness changes with depth. This disadvantage is offset by allowing a unique solution for depth to the basal detachment.

Geology Tectonic processes and structural

geology 892004 Diversion of faulting by hills: technical note Berrill, J B

See also: 892055, 892091

Q J Engng Geol V21, N4, 1988, P371-374

892001 Progress in understanding jointing over the past century Pollard, D D; Aydin, A

Bull Geol Soc Am VIO0, NS, Aug 1988, P1181-1204 Joints reveal rock strain accommodated by brittle fracture. They influence mineral deposition by guiding ore-forming fluids, provide fracture permeability, and significantly affect rock deformability and fluid transport. Past literature on joints is reviewed and the fundamental concepts are outlined. The geometry of joints, surface morphology of a single joint, shape, spacing, and density of joints, and joint sets are considered. Interpretation of geological features to investigate propagation, interaction, and strain accommodation and the mechanics ofjointing is discussed. 177 refs. 892002 Dynamics of fault creep Wesson, R L

Previous work showing that ruptures may divert around a building founded on a sedimentary layer overlying a strike-slip fault is extended for natural features such as hillslopes. An expression is derived for work done by the unit strike-slip offset on a planar rupture surface through a 2-D cohesionless sedimentary triangular hill. It is shown that the path of least work for rupture is away from the vertical in the downhill direction, and that the amount of deviation depends mainly on the slope of the hill, but hill size and distance between the hill toe and the strike of the fault in the basement rock also have an effect.

892005 Tectonic stress orientation and the seismic regime of a single fault Lokajicek, T; Spicak, A; Waniek, L

Tectonophysics V152, N3/4, 20 Sept 1988, P297-302

J Geophys Res V93, NB8, Aug 1988, P8929-8951 Tectonic displacement along faults occurs as seismic slip or aseismic fault creep, which may take place over long or short periods with displacements up to tens of millimetres. External stress acting along the fault, stress as a response of the surrounding medium to displacement, and resistance to creep of the fault are the controlling factors. Simple analyses assuming a rectangular dislocation, quasi-static model of fault creep and power law fault zone theology or multielement dislocation, quasi-static model and viscous theology are derived. These models explain many observed creep events.

Plate models were used to study the effect of tectonic stress orientation on a single fault, with tectonic stress represented by uniaxial compression, and stress orientation expressed by the angle between fault plane and direction of acting pressure. Results illustrate the great importance of tectonic stress orientation on the seismic regime of tectonic faults. Changes in fault inclination led to distinct changes in recurrence time intervals between individual seismic events and in the amount of seismic energy released. Only a limited zone in the fault plane was involved in the process of seismic energy release.

892006 Mass movement and geology in the upper reaches of the Kinu river Nakayama, Y Proc 5th International Symposium on Landslides, Lausanne,

892003 Geometry of planar domino-style normal faults above a dipping basal detachment Axen, G J

J Struct Geol VIO, N4, 1988, P405-411 Domino-style faults evolve through simultaneous rotation of both faults and beds. A model is presented which allows for non-parallel, unevenly spaced domino-style faults and a dipping basal detachment. First, parallel faults above a dipping detachment are considered and equations derived for extension, dip of detachment and rotation, using data available from the field or cross-sections. Domino-style faults in the field are not usually parallel, complicating the geometry since

10-15 July 1988 VI, P245-250. Publ Rotterdam: A A Balkema, 1988 The Kinu river valley Japan, predominantly granite and volcanic rock, is characterised by slope failure, thick river bed deposits and flowing water during the dry season. Geology and mass movement, rain warning systems, landslide dams, fluvial sand and gravel, hydrographic characteristics and deep irrigation wells are briefly described. A formula is developed to calculate stable slope angle.

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