Results 271 to 280 of about 35,897 (307)

Review on symmetric structures in ductile shear zones

International Journal of Earth Sciences, 2016
Symmetric structures in ductile shear zones range widely in shapes and geneses. Matrix rheology, its flow pattern, its competency contrast with the clast, degree of slip of the clast, shear intensity and its variation across shear zone and deformation temperature, and degree of confinement of clast in shear zones affects (independently) the degree of ...
openaire   +1 more source

An apparatus to experimentally model the dynamics of ductile shear zones

Tectonophysics, 1996
Abstract We present a ring-shear apparatus designed to deform soft, ductile rock analogues to arbitraily high shear strains in simple shear, in experiments attempting to model processes that occur in natural ductile shear zones. The sintered specimen is deformed between two unsupported cylinders by two rotating grips, under a normal and shear stress ...
Paul D. Bons, Janos L. Urai
openaire   +1 more source

Crustal-scale ductile shear zones in four dimensions

2021
Crustal-scale fault zones accommodate a significant portion of the relative motion between Earth?s tectonic plates, and are both a source of major earthquake hazard, and vital pathways for the mineralizing fluids that form several types of ore deposits.
openaire   +1 more source

Ductile shearing on top of the Eocene extruding wedge: the Combin Shear Zone

2019
A popular model for the exhumation of HP-UHP rocks is the ‘extruding wedge’ model, where a crustal sliceis bounded at its base by a ‘thrust shear-sense’ fault and to the top by a ‘normal shear-sense’ fault. In theWestern Alps, three main ‘normal shear-sense’ shear zones may have bounded extruding wedges at differenttimes during the Alpine orogeny ...
Ballevre, Michel, Manzotti, Paola
openaire   +2 more sources

Strain-induced mineral growth in ductile shear zones and a preliminary study of ductile shearing in western Newfoundland

Canadian Journal of Earth Sciences, 1988
In the Fleur de Lys and the Central Gneiss terranes the presence of strain-induced mineral growth characteristic of ductile shear zones within zones of rocks with mylonitic fabrics indicates the existence of major belts of layer-parallel ductile shearing with complex evolutionary sequences.
openaire   +1 more source

Structure and development of an anastomosing network of ductile shear zones

Journal of Structural Geology, 2010
A detailed structural analysis of an anastomosing shear zone network in metagabbros from the Archean Rainy Lake zone (Canada) revealed the existence of prevalent dextral and minor sinistral conjugate shear zones with the obtuse angle (>130°) facing the main shortening direction.
Jordi Carreras, Dyanna M. Czeck, Elena Druguet, Peter J. Hudleston   +3 more
openaire   +1 more source

The Palomares brittle—ductile Shear Zone of southern Spain

Journal of Structural Geology, 1987
Abstract The Palomares Shear Zone is a major Neogene-Quaternary strike—slip zone which transects the crust of the Betic Cordillera in SE Spain. The shear zone and the mechanisms that led to its formation are discussed and illustrated on the basis of detailed compilations of both the local and regional geology.
openaire   +1 more source

Ductile shear zones as counterflow boundaries in pseudoplastic fluids

Journal of Structural Geology, 1999
Abstract Ductile shear zones with different styles are attributed to rocks having deformed as pseudoplastic power law fluids with different exponents n >1 of the stress sensitivity of the strain rate. Profiles of velocity and accumulated displacements recorded by passive markers in pseudoplastic fluids flowing steadily and continuously along no-slip
openaire   +1 more source

Transcurrent ductile shear zones and the dispersal of the Avalon superterrane

Geological Society, London, Special Publications, 1990
Abstract A mosaic of steep, often sinistral, transcurrent shear zones cuts late Precambrian to earliest Cambrian rocks in eastern Canada, southern Britain, and northwest France. Examples include mylonite belts in Saint John (New Brunswick), Cobequid Highlands (Nova Scotia), Burin Peninsula (Newfoundland), Malverns (England), and N Brittany ...
openaire   +1 more source

Ductile shear zones – future perspectives

2020
<p>About 50 years ago, John Ramsay and colleagues established the thorough foundation for the field-scale observational and mathematical description of the structures, deformation, and kinematics in ductile shear zones. Since then, these probably most important instabilities of the ductile lithosphere enjoyed an almost explosive ...
openaire   +1 more source