We report here the petrography, mineralogy and in-situ trace-element mineral geochemistry of a rare and hitherto unidentified baddeleyite-apatite-spinel-phlogopite (BASP) rock in Late Neoproterozoic Achankovil Shear Zone (ACSZ) in South India. The rock unit occurs as isolated outcrops and demarcates the western boundary of an ...

The crustal structure toward southern part of SGT is poorly defined leaving an opportunity to understand the tectonic and geodynamic evolution of this high-grade granulite terrain surrounded by major shear and tectonically disturbed zones like Achankovil Shear Zone (AKSZ) and Palghat Cauvery ...

The Madurai Block, southern India, lies between the Palghat-Cauvery and the Achankovil shear zones. The Karur area represents a portion of the granulite-facies terrain of the Madurai block. High-pressure (HP) and ultrahigh-temperature (UHT) mafic granulites have been found as enclaves within the gneisses. The peak assemblage (M1) ...

Evidence for shear heating associated with crustal faulting is described for a number of fault zones

... Title : INVESTIGATION OF SHEAR ZONES IN THE ICE CAP MARGIN, THULE, GREENLAND. Descriptive Note : Research rept.,. ...

Surface rupturing during the 28 June 1992, Landers, California earthquake, east of Los Angeles, accommodated right-lateral offsets up to about 6 m along segments of distinct, en echelon fault zones with a total length of about 80 km. The offsets were accommodated generally not by faults -- distinct slip surfaces -- but rather by shear ...

Sep 1, 2011... fine sandy soil containing pine roots was placed in a large shear box in ... Root deformation in sheared soil is influenced by the diameter and ...

sandstone 1 MICROSTRUCTURE OF SHEAR ZONES IN FONTAINEBLEAU SANDSTONE A. El Bied, CERMES, Ecole Nationale des. Martineau,(2002) : Microstructure of shear zones in Fontainebleau sandstone 2 1. Introduction. El Bied, J. Sulem, F. Martineau,(2002) : Microstructure of shear ...

... Microtextural Characterization of Shear Textures in the Thermo-Mechanically Affected Zone of Friction Stir Processed Nickel Aluminum Bronze. ...

This work describes the geometric and kinematic characteristics of the Major Gercino Shear Zone (MGSZ) in the Canelinha-Garcia area. This shear zone is one of the major lineaments that affect all southern Brazilian precambrian terrains. In Santa Catarina ...

Deformations during heating and cooling of three drifts in granitic rock were influenced by the presence of faults and shear zones. Thermal deformations were significantly larger in sheared and faulted zones than where the rock was jointed, but neither sh...

The objective of this project is to understand the geologic control on distribution and availability of radon gas in areas where sheared fault zones cause localized, anomalously high concentrations of radon in rocks, soils, and water. Sheared fault zones ...

Frio Shear Zone: A major tectonic boundary in South Victoria Land, Antarctica. MSc thesis, University of Otago, Dunedin. Creation and Review Dates ...

Cutting by shearing creates heavy shear deformation in a layer extending between the two applied shearing edges. Prediction of FEM-simulation is that effective strain and strain rates in the shear zone would reach very high levels even at mode rate shearing velocity. In ...

Field occurrences of deep-level faults or shear zones commonly expose incomplete, 2-D views of the structures and evidence for the early history of the zone is commonly destroyed by progressive deformation. In contrast, shear zones in granitic rocks of the Hilgard Branch, central Sierra Nevada ...

Oblate strains are often observed in meso-scale ductile shear zones and this is generally taken to indicate narrowing across the shear zone during formation. Volume loss is one mechanism that could produce shear zone narrowing. However, not all shear ...

Failure in sheared-edge stretching often limits the use of advanced high-strength steel sheets in automotive applications. The present study analyzes data in the literature from laboratory experiments on both the shearing process and the characteristics of sheared edges. Shearing produces a surface with regions of ...

in the transition zone of the mantle. Keywords: garnet, shear zones, eclogite facies, Caledonides, Western Gneiss

under-plating along a shear zone or old suture zone as described by Fountain ... latter possibility of a suture zone. The Palghat-Tiruchi line may not be a ...

The objective of this project is to understand the geology of radon gas behavior in areas where shared fault zones cause localized, anomalously high concentrations of radon. Sheared fault zones in bedrock have been identified as the cause of some of the h...

Two sets of crenulations are commonly observed in shear zones. Both sets of crenulation planes are oblique to the boundaries of the shear zone. The morphologies and orientations of the crenulations sets and their spatial distributions indicate that they serve to compensate for displacement components of anisotropy ...

A tool setup designed for accurate bar shearing with zero clearance is described. The equipment is used to perform some accurate experiments for partitioning of small bars of an Al alloy. In the experiments a grid-pattern technique is used to map the actual deformations in the shear zone. Afterwards the shearing ...

... A simple model is used to relate the observed plug displacements to the ... zone strength, the threshold energy for shear plug displacement, and the ...

In the present study of adiabatic shear banding in metals, the region of interest is modelled as a two-material two-temperature body. Specific material laws governing thermoviscous plasticity and heat transfer ate ascribed to the shear-band zone. Momentum...

The Gran Paradiso nappe of the northwestern Alps mostly consists of augen gneisses derived from the Alpine deformation of Permian granitoids. The regional foliation of the augen gneisses developed at lower amphibolite facies conditions and is associated with a top-to-west sense of shear. The granitoid protolith is preserved in the kilometre-scale low-strain domain of the ...

Sodicgedrite in ultrahigh-temperature Mg-Al-rich rocks from the Palghat-Cauvery Shear Zone system, southern India

Numerical methods were used to investigate the deformation of a continental plate in northeastern Brazil. Of particular interest are the perturbations induced by a stiff compressional deformation of a highly heterogeneous continental lithosphere on the development of a shear zone formed at the termination of a stiff block.

... Military Park with recent geologic mapping superimposed. Shear zone between granitic rocks typical of the Charlotte belt ... The belts of metamorphosed rocks, faults, and shear zones resulted f...

Fundamental questions of applying the mechanics f the formation and propagation of elastic waves to the elastic part of the cutting zone are discussed in this book. Moving elastic fields existing in this zone below the shearing surface are investigated, a...

The transform zone connects the Rhone and Rhine rift segments; it is expressed as NE-trending fault valleys (zones of horizontal shear) and narrow, ...

... of the mixing zone of the shear layer, We have developed a flame sheet model for the simulation of combustion at high Damkohler numbers where ...

Jul 5, 2007 ... Metamorphic conditions in the Nilgiri Granulite Terrane and the adjacent Moyar and Bhavani Shear Zones: A reevaluation ...

The kinematics of rift propagation and the resulting goemetries of various tectonic elements for two

Late compressional deformation in connection with the formation of the Moyar and Bhavani shear zones to the north and south of the Nilgiri block, ...

HEAT AFFECTED ZONE. wanna WERE nmmutnan TO MEET sszczrxcarrun aaqurammnws. THIS PROBLEM HAS SEEN NOTED III HI-SHEAR PRODUCT ...

Applicability of Channel flow as an extrusion mechanism of the Higher Himalayan Shear Zone from Sutlej, Zanskar, Dhauliganga and Goriganga Sections, Indian Himalaya Soumyajit Mukherjee Department of Earth Sciences, Indian Institute of Technology Bombay Powai, Mumbai- 400076, INDIA, e-mail: soumyajitm@gmail.com Mukherjee & Koyi (1,2) evaluated the ...

The Acebuches metabasites constitute a slice of oceanic crust located at the Variscan suture between the Ossa Morena and the South Portuguese zones (Iberian Massif). The emplacement of the metabasites onto the accretionary prism was associated with the activity of the southern Iberian shear zone. Careful measurements of the fabrics and ...

Mantle reflections observed on deep seismic profiles across the northern North Sea may be tentatively interpreted as extensional shear zones. Modeling them as such explains many of the features of the basin, in particular the broad regions of postrift onlap onto the basin flanks. Consequently, it seems likely that the mantle reflections represent mantle ...

In the Neves area, the pre-Alpine intrusive protolith of the Zentralgneise unit (Tauern window, Eastern Alps) is well preserved in a kilometric-scale low-strain domain without pervasive Alpine deformation. It is compositionally heterogeneous, consisting predominantly of granodiorites, with lesser leucocratic granites, and different generations of lamprophyres and aplites. The intrusive rocks are ...

Employing analogue and numerical experiments, we investigated the process of plastic creep in the vicinity of stiff inclusions and its role in the formation of shear zones. Analogue experiments were performed on Polymethylmethacrylate (PMMA) models in pure shear (${\\dot{\\varepsilon} ~ 10-4 s-1), which produced ...

The metamorphic Piedmont of southeastern Pennsylvania is crosscut by a significant system of steeply dipping ductile shear zones with late- to post-orogenic transcurrent displacement. Geologic evidence suggests that at least some of these shear zones are responsible for hundreds of kilometers of dextral ...

Refraction and deflection of shear zones in layered granular materials were studied experimentally and numerically. We show that (i) according to a recent theoretical prediction [T. Unger, Phys. Rev. Lett. 98, 018301 (2007)] shear zones refract in layered systems in analogy with light refraction, (ii) ...

The objective of this project is to understand the geologic control on distribution and availability of radon gas in areas where sheared fault zones cause localized, anomalously high concentrations of radon in rocks, soils, and water. Sheared fault zones in bedrock have been identified as the cause of some of the ...

The authors address the question of the origin and meaning of the Harang discontinuity. They consider mappings of the ionosphere, auroral zones, and magnetosphere. They argue for a relation between the velocity shear zone in the auroral ionosphere and the Harang discontinuity. However because of the upward directed field-aligned ...

A characteristic tooth of rodents, the incisor continuously grows throughout life by the constant formation of dentin and enamel. Continuous eruption of the incisor is accompanied with formation of shear zone, in which the periodontal ligament is remodeled. Although the shear zone plays a role in the remodeling, ...

Continental thickening can be associated at depth with strain localization into anas- tomosing shear zones. These shear zones, formed during metamorphism, are often obliterated by later thermal and tectonic events possibly related with the exhumation of mountain roots under retrograde conditions. Anastomosing ...

The Variscan Moldanubian Zone in Austria is divided from E to W into three lithological units: Gf�hl, Variegated and Monotonous units. In the Amstettener Bergland and Strudengau area (Lower Austria), important new late- to post-Variscan deformation has been observed. Between Persenbeug and Weins, a low-angled mylonitic shear-zone (Strudengau ...

A 1 to 1.5 km-thick, high-temperature shear zone is localized in wall rocks subparallel to the eastern intrusive contact of the Permian Mafic Complex of the Ivrea-Verbano zone (IVZ), Italy. The shear zone is characterized by concentrated ductile deformation manifested by a penetrative foliation ...

The effect of shear deformation on the permeability of fractured rock has been investigated in drained triaxial compression experiments on prefractured samples of Coconino sandstone. These experiments show that permeability across a fracture decreases with increasing shear deformation because of localized deformation along the fractures and the evolution ...

A complex mylonite zone contains rock types of varied mineralogy and a range in mylonitic textures, depending on rock type and strain history. The field structural geologists working in a complex mylonite zone is interested in (1) internal deformation in the zone and (2) regional displacement (tectonic transport) predicted by ...

The volume of liquid held between two solid disks is called a liquid bridge. Liquid bridges have often been investigated for their importance in technological applications, particularly in the floating-zone method for crystal growth of semi-conductors. In this technique a molten zone, i.e., a liquid bridge is created between a polycrystalline feed rod and ...

The Raft River extensional shear zone is exposed in the Albion-Raft River-Grouse Creek metamorphic core complex. Several studies of ductile deformation have shown that it accommodated crustal stretching in Tertiary time during late orogenic collapse of the thickened Cordilleran crust. Progressive deformation that results from mixed pure and simple ...

The objective of this project is to understand the geology of radon gas behavior in areas where shared fault zones cause localized, anomalously high concentrations of radon. Sheared fault zones in bedrock have been identified as the cause of some of the highest indoor radon and water borne radon problems recorded in the United States. ...

At the 2005 Fall Meeting of the American Geophysical Union, Griffiths and Johnson [2005] introduced a method of extracting from the deformation-gradient (and velocity-gradient) tensor the amount and preferred orientation of simple-shear associated with 2-D shear zones and faults. Noting the 2-D is important because the ...

of the convergence between India and Asia. In Yunnan and Sichuan, for instance, the Ailao Shan^Red River shear zone the edge of the Tarim, the Altyn Tagh fault also ap- pears to cut the lithosphere (e.g. [3]) and contrib the Ailao Shan^Red River shear zone [1,2], such shear lasted for millions ...

The Amesmessa gold prospect is located along a vertical N-S-trending crustal-scale ductile shear zone; stretching lineations are subhorizontal. This major shear zone is a Late Pan African dextral strike-slip fault of the Pharusian Belt of the Tuareg Shield (Algeria). The Amesmessa shear ...

While much has been done to characterize phases of colloidal suspensions which are either equilibrated or driven out of equilibrium by an applied shear, very little is known about hybrid structures such as shear bands formed at the transition between these regimes. We have built a shear cell which can be loaded onto a confocal ...

At Nusfjord in Lofoten, Norway, three 0.3 - 3 m thick shear zones occur in a gabbro-anorthosite. During deformation, the shear zones were infiltrated by a hydrous fluid enriched in Cl. In the central parts of the shear zones, fluid-rock interaction resulted in complete ...

Dipping reflectors in the upper mantle are observed on reflection seismic data and, in some cases, have been interpreted to represent mantle shear zones. It is not clear, however, how these shear zones develop and under what circumstances. Previous attempts to model strain localisation by strain softening in the ...

The Ranotsara shear zone in Madagascar has been considered in previous studies to be a >350-km-long, intracrustal strike-slip shear zone of Precambrian/Cambrian age. Because of its oblique strike to the east and west coast of Madagascar, the Ranotsara shear zone has been ...

A model for the dynamics of aseismic strike-slip shear zones is proposed under conditions of constant rate out-side the zone and with an almost perfectly rigid plastic rheology for the rock. It is shown that a necessary condition for the activation of the shear zone is the existence of an ...

In the Lake Edison (LE) granodiorite (88Ma) of the Bear Creek area (Cretaceous Mono Pass intrusive suite, Sierra Nevada, CA) different sets of fractures developed during the high temperature stages of post-magmatic cooling. These fractures strongly localized successive ductile and later brittle shear deformation, but many pristine fractures do not show any ...

Rigid inclusion models have reached a stage where one should be able to use them to obtain quantitative values from ductile shear zones. We used natural data collected in three sites and combined analogue and theoretical modelling to assess vorticity, strain, nature of rigid inclusion/matrix interface and confinement in the large-scale, ductile ...

... 0 1 2 Wall Thickness (inches) SCG Single Wall MxdControl Multi-wall ... FIGURE 1. Fracture and Control Zones. (SCG = Shear Control Grid.) 4 Page 9. ...

The two principal mechanisms for hot spots generated in XDT are thought to be shear cracking and shear banding. Casual observation would not be sufficient to distinguish between the two in dynamic processes, since in either case a molten zone will develop...

The main contention of this paper is that the Gulf and Caribbean lie in a zone of north-south extension and left-lateral shear between crustal areas spreading in different directions at different rates. Ridge migration and extension have been explained as...

The shear moraine phenomenon of glaciers is examined in the light of new evidence collected in the general Tuto area during 1958-1959. The formation and composition of silt bands, some heavy accumulations of boulders and gravel, and streaks of clayey ice ...

Describes the three processes of folding in rocks: buckling, bending, and passive folding. Discusses how geometrical properties and strain distributions help to identify which processes produce natural folds, and also provides information about the mechanical properties of rocks, and the sense of shear in shear zones. (TW)

The detection of the interface between turbulent and nonturbulent zones in slightly heated turbulent shear flows on the basis of a temperature signal is discussed. Two detection parameters, a threshold level and a hold time are used. A complete descriptio...

Kinematic, kinematic vorticity (Wm), and deformation temperature analyses were completed to test the hypothesis that midcrustal rocks exposed in the core of the Kangmar gneiss dome, southern Tibet record ductile deformation patterns of a �frozen� segment of a southward flowing midcrustal channel. Microscopic and mesoscopic kinematic indicators exhibit a downward transition from a subequal mix ...

These rocks were collected from outcrops frequented by structural geology field trips. CCM 42 is from the town of Clare, CCM 43 is from Russell; although labeled CCM, neither is from the Carthoage Colton Mylonite Zone, but both are from shear zones. DEK is from the world famous DeKalb anticline. In this lab we try to pull together ...

Five major fault systems join at the SW termination of the Tauern Window: The dextral Pustertal Line, the Brenner normal fault, the sinistral DAV Line, the sininstral Ahrntal Fault and the sinistral Giudicarie fault system. This study focuses on the extent and tectonic significance of the Ahrntal Fault. This Structure is shown as a sinistral strike-slip fault in numerous tectonic maps of the ...

Within the Central Gneiss Belt (CGB) of the southwestern Grenville Province, Ontario, Canada, a number of allocthonous lithotectonic domains are juxtaposed along crustal-scale shear zones. Extensive exposure of variably reworked granulites of the interior Parry Sound domain (iPSD) has enabled investigation of the structural and petrologic character of ...

Kelemen and Hirth (Fall 2004 AGU) presented a model for periodic, viscous shear heating instabilities along pre-existing, fine grained shear zones. This provides an attractive alternative to dehydration embrittlement for explaining intermediate-depth earthquakes, especially those in a narrow thermal window within the mantle section of ...

The shear mode of ductile fracture has been investigated in a spheroidized plain carbon steel by optical microscopy, scanning electron microscopy and transmission electron microscopy. The results from these techniques are brought together to obtain a detailed description of the shear mode of fracture in this material. The fracture occurs by the following ...

Experiments combined with FEA is applied to study how the shear zone formed between the upper and the lower shearing edge in conventional shearing is influenced by the initiation and growth of a crack into the cut-off surface of the blank material when sharp-edge dies are used. The formation and propagation of such ...

Shear instability is the dominant mechanism for converting fluid motion to mixing in the stratified ocean and atmosphere. The transition to turbulence has been well characterized in laboratory settings and numerical simulations at moderate Reynolds number�it involves �rolling up�, i.e., overturning of the density structure within the cores of the instabilities. In ...

Petrologic and geochemical changes in ductile shear zones are important for understanding deformational and geochemical processes of the continental crust. This study examines three shear zones that formed under conditions varying from lower greenschist facies to upper amphibolite facies in order to document the ...

We offer three new concepts that help place constraints on the mechanics and width of plate-boundary shear zones below the brittle-ductile transition. 1. Lithospheric shear zones operate at approximately constant stress at any given depth (temperature). This is because shear ...

Eur. Phys. J. E 28, 73�78 (2009) DOI: 10.1140/epje/i2008-10418-0 Wide shear zones and the spot Wide shear zones and the spot model: Implications from the split-bottom geometry E. Woldhuisa , B � c EDP Sciences / Societ`a Italiana di Fisica / Springer-Verlag 2009 Abstract. The spot model has

The authors have studied strain and fabric development in small ductile shear zones produced under amphibolite facies conditions in the Eastern Amphibolites of the Seve-Koeli nappe complex in the northern Swedish Caledonides. These rocks are particularly favorable for such a study because three independent measures of aspects of the deformation can be ...

Strong shear zones were found between 70 and 120 km (44 and 75 mi), apparently arising from internal "gravity waves." The bright auroras were excited by ...

May 29, 2006 ... The outgoing, or ebb, current from Playa Colorado Bay is visible at upper ... This density difference causes obvious shear zones along the ...

... be supercritical in cascades and waterfalls. Shear stress, Froude number, and Reynolds number�all measures considered more pertinent ... ...

Mar 1, 2011 ... Late compressional deformation in connection with the formation of the Moyar and Bhavani shear zones to the north and south of the Nilgiri ...

... where maximum plastic zones sizes are small compared to the grain size, fatigue crack growth proceeds by a single shear decohesion mechanism ...

... were observed throughout most of the 142 m interval and were used to distinguish lithologic boundaries and zones of fracturing as interpreted by ...

Reservoir compartments, typical targets for new infill locations, are commonly created by faults that may reduce or enhanced permeabilities. Faults often contain narrow zones of intense shear comprised of geometrically complex elements that reduce permeability and compartmentalize blocks as a function of time and pressure. This thesis characterizes the ...

... Corporate Author : OREGON STATE UNIV CORVALLIS. ... been used to provide Graduate Research Assistant (GRA) salary and tuition support for ...

... monzonite and quartz diorite. Near the Brookneal shear zone, deformation textures in the granite ... due to potential radon problem. May be susceptible to mass was...

... and microchemical data through analytical SEM/EDS and WDS microscopy; .... G . KLEINSCHMIDT, F. TALARICO - 'The Mertz Shear Zone: new evidence of the ...

... and microchemical data through analytical SEM/EDS and WDS microscopy; .... G . KLEINSCHMIDT, F. TALARICO - 'The Mertz Shear Zone: new evidence of the ...

the Nilgiri block and the adjacent shear zones and to assess ... margin of the Nilgiri H i l l s reported by earlier workers (6,7) ...

rock material en masse. Usually the displaced material move over a relatively confined zone or surface of shear. The wide range of sites and structures, and ...

... are believed to be the product of mesothermal, multiphase mineralization. K-Ar dating of shear-zone sericite ... ...

... yaw has a very destabilizing effect on the ... conducted on a swept airfoil model [the complete ... disturbance predominates in the concave zone instead ...

This density difference causes obvious shear zones along the current boundary, ... Water Views: BAY, GULF, OCEAN, PLAYA, SUNGLINT, WAVE. Atmosphere Views: ...

Jan 22, 2011 ... Dec-1994, Where is the Eastern California Shear Zone North of 37N Latitude? Wang , H.; Dixon, T.; Donnellan, A. ...

Jan 1, 1988 ... Title: Metamorphic conditions in the Nilgiri Granulite Terrane and the adjacent Moyar and Bhavani Shear Zones: A reevaluation ...

... It appears the greater thermal ... Stress Matrix Cracks Redistribute Stress Shear Damage Zone Redistribute Stress ... 1.4 Creep and Fatigue Loading ...

The Nilgiri granulite terrane in Southern India is predomi- ... Bhavani shear zones to the north and south of the Nilgiri block, ...

It is proposed that: volumetric dilation is a fundamental requirement for brittle fracture involving shear; such dilation commonly involves or is expressed as zonal overpressures; the overpressured zones radiate particle motions which are significant to o...

... shear strain zone can b-. extended by making the beam longer and the adhesive layer thinner. Therefore, for some adhesives, for which a tough ...

... light weight deflectometer (LWD), which measures dynamic deflection modulus (bearing strength); dynamic cone penetrometer (shear strength ...

... wind shear in and near the terminal approach and departure zones of the airport. ... WSP may be used as a stand-alone system at airports without a ...

Geochemical and petrographic studies of the Triassic Portoro limestone of the Tuscan nappe in Liguria, Italy, indicate that fluid flow was channeled through interlayered bedding-parallel shear zones during Miocene shearing and low-grade metamorphism. Carbon, oxygen, and strontium isotopic compositions and trace element concentrations ...

The Hyde Macraes Shear Zone (HMSZ) is a mineralised low-angle shear within the Otago Schist traceable for � 30 km with a NW strike. It is being actively mined along 12 km of this strike, producing > 6 Moz of gold. The shear zone formed under lower greenschist facies conditions as the host ...

When a (dense) granular material is sheared in shear-cell experiments, shearing remains confined to a narrow localized zone ("shearband") near the moving boundary. Such shear-banding has also been realized in the molecular dynamics simulations of granular plane Couette flow for a range of ...

Despite intensive efforts, determination of a predictable pattern of gold distribution to enhance process understanding and simplify exploration has remained elusive. The pattern of gold distribution along the Archean Boulder-Lefroy shear zone in the Yilgarn craton of Western Australia provides insights into gold distribution in one of the world's richest ...

High-pressure granulites of the Bacariza Formation (Cabo Ortegal Complex, NW Spain) exhibit spectacular examples of ductile shear zones developed at different scales in rocks containing pre-existing foliations. A detailed structural analysis was carried out on these shear zones in order to unravel and compare the ...

The authors study the initiation and growth of shear bands in prismatic bodies of rectangular cross-section made of either depleted uranium or tungsten and deformed in plane strain compression at a nominal strain-rate of 5000/s. It is found that, in the deformed configuration, shear bands in depleted uranium blocks are inclined at approximately 42.5 deg ...

The Raft River Mountains of northwestern Utah expose a detachment fault that separates a hanging wall of Paleozoic rocks from Proterozoic ( ) and Archean rocks of the footwall. Beneath the detachment lies a 100 to 300m-thick top-to-the-east extensional shear zone. Geologic mapping, strain and kinematic analysis, and [sup 40]Ar/[sup 39]Ar thermochronology ...

The wind-shear theory of the formation of temperate-zone sporadic E layers is extended to take into account effects associated with a neutral wind profile having a descending phase velocity. It is shown that layers of long-lived ions (presumably of meteor...

An error was discovered in the ALGEBBRA script used to calculate the disturbed rock zone around the disposal room and the shear failure zone in the anhydrite layers in the original version. To correct the error, a memorandum of correction was submitted ac...

Mar 10, 1997 ... At Jupiter's belt-zone boundaries the shearing wind velocities can reach nearly 300 miles per hour. Near infrared images recently returned ...

Plane strain problem of an interface crack with two interface shear yield zones and one crack-face contact zone is studied. The plastic yielding of the interlayer is stimulated by the interface shear yield zones and contact zone is included near one tip of the interface ...

A major issue with in situ subsurface remediation is the ability to achieve an even spatial distribution of remedial amendments to the contamination zones in an aquifer or vadose zone. Amendment delivery to the aquifer using shear thinning fluid and to the vadose zone using aqueous foam has the potential to enhance ...

Large-scale shear zones are distinct features of Tibet-Himalayan orogen and the Pan-African Trans-Saharan belt. Prominent examples in the Pan-African-belt extend for ~2500 km from the Sahara to the Gulf of Guinea and are characterized by right-slip movements. The NS shear zones, such as 4�50�-Kandi ...

Lozenges are characteristic common structures related to anastomosing networks of shear zones. They are ellipsoid-shaped bodies of undeformed (or less deformed) country rock bounded by mylonites. They have been studied since the 1980's (Bell and Rubenach 1980, Bell 1981, Simpson, 1982, Choukroune and Gapais 1987, Hudleston 1999, Fusseis 2006), and various ...

This paper discusses the Ohio shale, problems associated with finding productive zones, the theory of using sonic data in addition to the conventional suite of logs, and the sonic shear wave-resistivity overlay technique. It is shown that the identification of possible productive zones in the Ohio shale is greatly facilitated by adding ...

Examples of mineral transformations in the zone of faults, which limit the Aldan Shield from the south, in the limits of the Ukrainian Shield and Voronezh crystalline massif, and also in the xenoliths from the kimberlites of East Siberia and alkaline basalts of Mongolia are examined. The role of shear stresses and strains of the rocks and minerals caused ...

with conventional detailing of reinforcement can be affected by shear deformations in the inelastic zones (Celebi and the number of postyield load cycles. It is reported by Celebi and Penzien (1973) that the area enclosed of the section. Different models of shear behavior have been proposed in the literature (Celebi and Penzien 1973

plastic zone passes (Fig. 4). Besides, this is in agreement with the fact that shear strain accomodation of grain internal structure [3]. Accomodation of structural nonconformities at the translation shears of uniform structural elements accomodating the translational shear due to the rotational modes. In fine

The dynamic shear stress of glass beads has been measured to study the effects of experimental parameters including shearing zone height, water fraction, bead size, and bead size distribution. A method is proposed to obtain the true shear stress from the ...

The Purcell Trench of southern British Columbia and northern Idaho marks the location of an Eocene, east-dipping normal fault that juxtaposes migmatite and coarsely crystalline rocks on the west with relatively unmetamorphosed rocks of the Belt Supergroup and shallow plutons on the east. Well west of the projected Purcell Trench, a broad zone of plastic ...

We present the results of numerical simulations of Slow Slip Events (SSEs) using a novel formulation for displacement in the lithosphere caused by semi-brittle fracture instabilities. We models SSEs as slip on fluid filled shear fractures that undergo metamorphic reactions leading to the formation of a weak viscous phase in the fracture. This weakening process allows for the ...

Comparison of analogue experiments at crustal and lithospheric scale provides essential information concerning the mode of deformation during lithospheric extension. This study shows that during extension, lithospheric deformation is controlled by the development of shear zones in the ductile parts. At lithospheric scale, the global deformation is ...

Comparison of analogue experiments at crustal and lithospheric scale provides essential information concerning the mode of deformation during lithospheric extension. This study shows that during extension, lithospheric deformation is controlled by the development of shear zones in the ductile parts (i.e., the lower crust and the ductile mantle ...

A > 3 km thick, ductile, east-trending shear zone in the Pinal Peak map area, near Globe, Arizona, reveals contact metamorphism of the Pinal schist, through intrusion of the Proterozoic Madera granodiorite, and synchronous deformation of both units. The exposed shear zone comprises approximately 40 anastomosing ...

The mechanism of extension in the continental crust is apparently much more complex than that acting in the oceanic lithosphere. Recently, Wernicke has proposed that a significant fraction of extension in the continental lithosphere may occur by a simple shear mechanism along discrete fault/shear zones which cut the crust, and perhaps ...

We report experimental characterization of shear transformation zones (STZs) for plastic flow of bulk metallic glasses (BMGs) based on a newly developed cooperative shearing model [Johnson WL, Samwer K (2005) A universal criterion for plastic yielding of metallic glasses with a (T/T_g)^2/3 ...

Laumontite mineralization is pervasive in joints and shear zones encountered in the Cajon Pass drillhole in southern California. In order to determine whether a gouge composed of this hydrated mineral affects shear strength in a manner similar to low-strength, clay-rich fault gouges, frictional sliding experiments were performed under ...

Due to the growing ranges of applications for stamped parts in the electrical and electronics industry (e.g. switch cabinet cladding and transformer plates) as well as in the automotive industry (e.g. stamp, bent and drawn components), flexible sheet metal forming has become a more important process. The inner and outer contours as well as the forming operations needed to reinforce metal sheets ...

Deformations during heating and cooling of three drifts in granitic rock were influenced by the presence of faults and shear zones. Thermal deformations were significantly larger in sheared and faulted zones than where the rock was jointed, but neither sheared nor faulted. Furthermore, thermal ...

This study demonstrates how the variability of the VAD (Velocity Azimuth Display) pattern obtained with a Doppler radar may be used to map qualitatively the turbulent regions in a snowstorm. The synoptic situation is presented; time-height plots of reflectivity, wind direction, wind speed, and vertical wind shear are discussed; and the association between characteristic ...

Based on the recent high-resolution laboratory experiments on propagating shear rupture, the constitutive law that governs shear rupture processes is discussed in view of the physical principles and constraints, and a specific constitutive law is proposed for shear rupture. It is demonstrated that nonuniform distributions of the ...

An investigation of the boundary layer viscosity of films of nonpolar liquid lubricants, hexadecane and a silicone oil, octamethyl-cyclotetrasiloxane, confined between parallel atomically smooth single crystals of muscovite mica, is reported. The effective viscosity (eta sub eff) showed a zone of linear response and a second zone of extreme ...

An investigation of the boundary layer viscosity of films of nonpolar liquid lubricants, hexadecane and a silicone oil, octamethyl-cyclotetrasiloxane, confined between parallel atomically smooth single crystals of muscovite mica, is reported. The effective viscosity (eta sub eff) showed a zone of linear response and a second zone of extreme ...

A wrench-fault type shear zone of at least 6 km width was found in the Precambrian basement of the Jbel Sirwa (Central Anti-Atlas, Morocco). It is explained by lateral slip of an (unknown) northern continental mass along the northern margin of the West African Craton. The deformation in the shear zone increases ...

, extensional shear-zone, monazite U-Th/Pb chemical dating, Armorican Massif, Variscan Belt Abstract. - This study presents new structural and monazite chemical U-Th/Pb geochronological constraints.2113/gssgfbull.180.3.247 #12;2 yielded by the monazite in the dykes comply with the interpretation of a synkinematic

We propose a solar dynamo model distributed in the bulk of the convection zone with toroidal magnetic-field flux concentrated in a near-surface layer. We show that if the boundary conditions at the top of the dynamo region allow the large-scale toroidal magnetic fields to penetrate close to the surface, then the modeled butterfly diagram for the toroidal magnetic field in the ...

This report presents an evaluation of Tertiary deposits and volcanic-related activity along the Maidu East shear zone at Auburn Damsite. The evaluation characterizes the lithology and structure of the Tertiary Mehrten Formation and within the Maidu East s...

solely due to metamorphic processes can result from changes in external conditions (e.g., Tracy 1976 to be preserved. Pressures and tempera- tures calculated from these rocks may be spurious. The Greiner shear zone of those calculations. Regional geology and previous work The Greiner shear zone is a subvertical, ...

Lithospheric anisotropy structure inferred from collocated teleseismic and magnetotelluric indeterminate depth information. Magnetotelluric electrical anisotropies are depth-constrained, and thereby structure inferred from collocated teleseismic and magnetotelluric observations: Great Slave Lake shear zone

the southwest coast of Norway. In: Meissner, R., Brown, L., Du�rbaur, H., Franke, W., Fuchs, K. & Seifert, F. 675 The Hardangerfjord Shear Zone in SW Norway and the North Sea: a large-scale low-angle shear zone 600 km long low-angle extensional structure that affects the South Norway and North Sea Caledonides

Ultrasonic Rayleigh wave measurements made earlier on several different types of adhesives have led to the finding of a distinct gradient in shear modulus through the interfacial accommodation zone. As reported here, different preparations of substrate appear to have little effect on the nature and extent of the modulus gradient. However, cure time is ...

During the Brasiliano-pan-African orogeny, a complex continental-scale pattern of east-west transcurrent shear zones and northeast-trending fold belts formed in the northern and central Borborema province of northeastern Brazil. The east-west shear zones have been usually regarded as slightly younger features, but ...

In this work we present structural, petrological and fluid inclusion studies performed in a major retrogressive shear zone (the Erbalunga shear zone), which occurs within the HP/LT domain of the Schistes Lustr�s Nappe of eastern Alpine Corsica. This shear zone is part of ...

The failure of a two-dimensional packing of elastic grains is analyzed using a numerical model. The packing fails through formation of shear bands or faults. During failure there is a separation of the system into two grain-packing states. In a shear band, local "rotating bearings" are spontaneously formed. The bearing state is favored in a ...

Deformation in the ductile crust and lithospheric mantle is localized as a result of a variety of strain-related weakening processes. The degree of localization depends on rock composition, water content, temperature, and strain rate, and in general decreases with increasing temperature and depth in the lithosphere. Lithospheric-scale ductile shear zones ...

Localized ductile shear zones with widths of cm to m are observed in exposures of Earth's shallow mantle (e.g., Kelemen & Dick JGR 95; Vissers et al. Tectonophys 95) and dredged from oceanic fracture zones (e.g., Jaroslow et al. Tectonophys 96). These are mylonitic (grain size 10 to 100 microns) and record mineral cooling ...

Networks of kinematically-related Alpine shear zones in the Mont Blanc granite have localised fluid flow, hydrothermal alteration and associated vein formation at mid-crustal depths during Alpine collision, in response to NW-SE shortening and vertical extrusion. Calcite-quartz d18O and fluid inclusion thermometry on shear-hosted veins ...

Natural rocks which have deformed by simple shear commonly exhibits an asymmetric quartz c-axis fabric which can be a useful kinematic indicator. Although there is some controversy on the sense of asymmetry from theoretical models, fabrics measured from natural rocks generally exhibit an asymmetry with maxima inclined in the direction of shear. The authors ...

The extensional Bitterroot mylonite zone defines the eastern and southern border of the Bitterroot metamorphic core complex and is generally interpreted to be the major structure which accommodated unroofing of the metamorphic core. The most commonly cited evidence for the age of mylonitization are [sup 40]Ar/[sup 39]Ar ages for hornblend, muscovite, biotite, and potassium ...

The channel flow hypothesis states that mid-crustal rocks in southern Tibet flowed southward toward the Himalayan front. Channel flow is driven by a low-viscosity mid-crust, a horizontal pressure gradient between Tibet and India, and surface denudation along the southern flank of the high Himalaya. Flow is predicted to be top-N simple shear at the top of the channel grading ...

We are pleased that experimental research in fluid flow in deformed sediments has continued since our original results (1990) and acknowledge the helpful contribution of Brown and Moore to this important topic. The 1988 results showed that permeability in directions close to parallelism with shear zones in clays was considerably greater than that in a ...

How does decoupling occur at depth in the intermediate to lower continental crust? Insight is obtained from the TRANSALP, NFP, and ECORP-CROP geological-geophysical transects of the Periadriatic Fault System (PFS), an exhumed, late-orogenic fault bounding the retro-wedge of the Alpine orogen. The PFS accommodated 100+ km of Oligo-Miocene dextral strike-slip between Alpine-metamorphosed units to ...

Shear instability occurs in estuaries in association with transitions to supercritical flow. Observations of shear instability in the Connecticut River estuary using broad-band echo sounders and a ship-mounted turbulence-measuring array provide unprecedented resolution of the transition from shear instability to turbulence at high ...

Pacific - North America displacement in California is distributed over a zone of intracontinental deformation 400 km wide, and incorporates large regions of transtensional and transpressional deformation. This pattern of deformation is not easily explicable in terms of brittle Coulomb failure, which should localize deformation on to a single fault. There is no consensus at ...

Postseismic deformation is well documented in geodetic data collected in the aftermath of large earthquakes. In the postseismic time interval, GPS is most sensitive to creep in the lower crust or upper mantle activated by earthquake-generated stress perturbations. In these regions, deformation may be localized on an aseismic frictional surface or on a ductile shear ...

The Lloyds River Fault Zone is a 10-15 km wide amphibolite-grade shear zone that formed during the Ordovician Taconic Orogeny. It separates ophiolites and arc-back-arc complexes formed in Iapetus from a peri-Laurentian microcontinent (Dashwoods microcontinent). The Lloyds River Fault Zone comprises three ...

We present a model for the short to secular time scale dynamics of the lithosphere in which ductile shear zones are activated by brittle fracture in regions where the lithosphere is populated by both viscous-plastic and frictional elastic mineral phases. According to our model, a fracture generates an elastic load that drives both ductile and brittle ...

In the recent past, a new faulting mechanism has been documented within porous carbonate grainstones. This mechanism is due to strain localization into narrow tabular bands characterized by both volumetric and shear strain; for this reason, these features are named compactive shear bands. In the field, compactive shear bands are easily ...

The aim of this paper is to better understand the material behaviour involved in machining operations. During machining, the workpiece experiences large strains, high strain rate, high temperatures, complex loading histories, and recovery. To reproduce these loadings and to understand the behaviour of 100Cr6 bearing steel, quasi-static and dynamics mechanical shearing tests ...

The high grade metamorphic massifs (e.g. Xuelong Shan, Diancang Shan, Ailao Shan in China and Day Nui Con Voi metamorphic massif in Vietnam) along the Ailao Shan-Red River shear zone in Southwestern China bear much information on the large-scale left-lateral strike-slip shearing in eastern Tibet during Indian-Eurasian plate collision ...

The plate boundary conditions of the western United States are well known from reconstructions based on oceanic seafloor spreading patterns, making the area an ideal location to address the association of magmatism and continental breakup. A major plate rearrangement occurred at 18 Ma on the west coast of the US, including the cessation of Monterey microplate spreading center, initiation of the ...

The bulk of the exhumation of (ultra)high-pressure rocks usually occurs soon after these rocks were metamorphosed in the course of lithospheric convergence and deep underthrusting during early orogenic stages. A number of studies have demonstrated great exhumation rates during these early exhumation stages. It is poorly understood, however, how this early exhumation is being kinematically ...

This paper presents a simple quantitative model for the transfer of lithospheric extension along deep crustal shear zones during rifting of continents. These shear zones are interpreted to connect laterally offset pre-existing weaknesses in the crust to the centre of mantle lithospheric thinning, the rift axis. ...

The Kapitan-Dimitrievo pluton was emplaced within the 15 km wide Maritsa shear zone during the Late Cretaceous. It has well-known U-Pb zircon age (78.54 � 0.13 Ma) and appears as a late-syntectonic intrusion that marked the last ductile deformation in the Maritsa shear zone. Magnetite is believed to be the main ...

A new seismic model of the three-dimensional variation in shear velocity throughout the Earth's mantle is presented. The model is derived entirely from shear bodywave travel times. Multibounce shear waves, core-reflected waves and SKS and SKKS waves that travel through the core are used in the analysis. A unique aspect of the dataset ...

Why is the Earth the only planet to display Plate Tectonics? Mantle convection on Venus and Earth generates fairly similar stresses, but the Venusian lithosphere remains intact while the Earth�s becomes mobile. A reduction of the strength of the terrestrial lithosphere is necessary to explain the difference between these planets. Brittle failure is inferred to occur to similar depths on Venus ...

Seismic shear waves can be generated with sufficient strength to be usable in refraction profiles out to a distance of 1800 ft under high seismic noise conditions. Greater distances can be achieved with multiple sources and multiple sensors. Over a known anomalous zone (cavity or cavity plus roof fall zone) large reductions in ...

Greenville-age rocks are exposed in the Beaver Creek area in the Northwest Lowlands of New York State. The prominent structural grain in the area strikes approximately N40E and is defined by a series of metasedimentary and metaigneous rocks elongate parallel to the Beaver Creek Fault Zone. A series of 7 granitic augen gneiss bodies lies to the west of the fault. These bodies ...

Shear zones from the Piedmont Province in the Southern Appalachian Mountains have progressively modified a pre-existing fabric in biotite-hornblende gneisses. In the pre-deformed gneiss a sub-horizontal L-fabric of varying intensity is found. This fabric changes progressively to an S-fabric towards the center of the localized ductile ...

Using the 3-dimensional ASH code, we have studied numerically the instabilities that occur in stellar radiation zones in presence of large-scale magnetic fields, rotation and large-scale shear. We confirm that some configurations are linearly unstable, as predicted by Tayler and collaborators, and we determine the saturation level of the instability. We ...

One of the most frequently encountered problems in structural analysis of complexly deformed metamorphic terranes is the determination of the sense of movement in sheared rocks. In regions composed of accreted terranes, such as the Klamath Mountains, such information can shed light on the relative motions of large blocks of crust and may enhance our understanding of the ...

Propagation of shear waves produced by 25 mantle earthquakes (80-600 km depth) in the subduction zone of the south Tyrrhenian Sea (southern Italy) has been investigated to infer the geometry and extent of the descending lithosphere. From all hypocentral depths high-frequency, high-amplitude shear waves are recorded at most of the ...

Venera 15 and 16 spacecraft images show clear evidence of major crustal disruptions on Venus which have been interpreted to indicate crustal divergence. Complementary to the divergent zones are mountain belts that border the continent-like high terrains. The requisite transcurrent motions appear to be manifested as diffuse shear zones. ...

The 1989 Loma Prieta, California, earthquake is characterized by the lack of major, throughgoing, coseismic, right-lateral faulting along strands of the San Andreas fault zone in the epicentral area. Instead, throughout the Summit Ridge area there are zones of tension cracks and left-lateral fracture zones oriented about N45 deg W, ...

Throughout the Higher Himalayan Shear Zone (HHSZ), the northeasterly dipping main foliation planes that acted as the primary shear planes (the C-planes) are rarely sub-horizontal. S-C fabrics, sigmoid quartz veins and leucosomes, and asymmetric intrafolial folds denote a top-to-SW sense of ductile shearing. The ...

Subsequent to the initial impoundment of the Bad Creek Reservoir in northwest South Carolina in January 1991, lake level fluctuations (up to 33 md-1) caused delayed (98 hours) correlative water level changes in an observation well (OW3) 250 m away. The bottom of the well is connected to the bottom of the reservoir by a shallowly dipping, 1 m wide shear ...

Earthquakes in the major fault zones are predominantly deep. Earthquakes in the crustal blocks bounding the fault zones are predominantly shallow. In the San Jacinto fault zone, maximum earthquake depths correlate with surface heat flow. These relations together with focal mechanisms, geodetic strain measurements, and fault ...

Metasediments of the upper greenschist - lower amphibolite facies of metamorphism from two ductile shear zones of Flin-Flon Belt (FFB) of Trans-Hudson Orogen (THO) were used to carried out laboratory measurements of compressional wave (Vp), shear-wave (Vs) velocities and shear-wave splitting. The investigated ...

The Ollo de Sapo domain of the northern part of the Variscan belt of Spain, contains Precambrian and Ordovician metamorphic rocks intruded by the Guitiriz granite. The domain is bounded by two N-S transcurrent shear zones. Detailed structural and anisotropy of magnetic susceptibility studies of the Guitiriz pluton reveal a syntectonic emplacement, relative ...

We investigate a detailed spatial variation in shear wave splitting in the zone of inland high strain rate, called the Niigata-Kobe Tectonic Zone (NKTZ), central Japan. Most observations show stress induced anisotropy, that is, the orientation of the faster polarized shear wave is parallel to the axis of the ...

The temperature field in combustion chamber of spark ignition engine is measured using laser shearing interferometry and high-speed photography in this paper. A set of experimental facility is set up. The relationship equation between the interference fringe image and temperature distribution is deduced. Changing the shearing interferometry quantity, the ...

Regional-scale arcuate structures in the central part of the Archean Yilgarn craton, Western Australia, were generated by impingement of competent granitoid blocks into less competent greenstone belts during progressive east-west shortening. Sinistral shear zones developed along northwest-trending margins of the granitoid blocks, whereas dextral ...

The mid-Cretaceous Salmon River suture zone of west-central Idaho marks the boundary between the North American craton and the accreted terranes to the west. The arc-craton boundary in this part of the Cordillera is defined by sharp gradients in the Sr and O isotope ratios, indicating that oceanic lithosphere is juxtaposed directly against continental lithosphere. The ...

The Border Ranges fault system in southern Alaska forms the tectonic boundary between the Peninsular-Alexander-Wrangellia (PAW) composite terrane and the Chugach terrane. In Glacier Bay National Park, the Border Ranges fault system is a north-northwest trending, 10 kilometer wide zone of ductile shear zones and brittle faults hereafter ...

Quantifying the microfracture damage surrounding faults and fractures is important for predicting the fluid flow properties of rock masses. Damage surrounding faults has been attributed to fault growth, geometric irregularities, and earthquake rupture. Up to now, earthquake rupture can only be inferred when pseudotachylyte is present, indicating shear heating leading to melt ...

American plates and low shear strength along the fault zone [Mount and ...... Biot, M.A., Theory of folding of stratified viscoelastic media and its ...... non-transform portions of fracture zones act as lithospheric weak zones. In ..... established strong ties to this network and are cooperating with RCFCD ...

Pulverized rocks in the Mojave section of the San Andreas Fault Zone Ory Dor a,, Yehuda Ben section of the San Andreas Fault in the Mojave Desert. The results show that almost every outcrop shear. We find structural similarities between the San Andreas Fault zone and exhumed faults of the San

Characterizaion of discontinuities such as faults, shears, and joints in a rock mass is an integral part of many geotechnical data acquisition programs. Discontinuity orientations are in practice measures in rock core samples or are mapped from rock exposures. Data sets thus obtained are biased because of blind zones associated with each borehole or ...

of the forearc [McCaffrey, 1993], the transient shear stress magnitude on the fault [Wang et al., 1995, 1992], Japan-Nankai [Hyndman et al., 1995], and Alaska [Savage and Plafker, 1991] show that during fault zone is held by a discrete distribution of high strength asperities separated by weak zones

: R.D. van der Hilst Keywords: geodesy fault evolution InSAR rock mechanics Western United States zone, the focus of this study (Fig. 1). The State Line fault, east of the Death Valley�Furnace Creek Eastern California Shear Zone Hunter Mountain Fault We present new space geodetic data indicating

The propagation of pressurized fractures across a frictional interface is discussed, with emphasis on the case where an offset, or step, in the crack is produced. Theoretically, the steps can occur at regions of reduced shear strength along the interface. As a fracture is propagated toward a weak zone, extensional strain is concentrated at the edges of the ...

A previously unrecognized, 12-10 Ma clastic sequence is distributed widely south of the Las Vegas Valley shear zone and north of Lake Mead in southern Nevada. Structural and stratigraphic evidence from these sedimentary and associated volcanic rocks suggests that basin development was kinematically related to movement along the Las Vegas Valley ...

A previously unrecognized, 12-10 Ma clastic sequence is distributed widely south of the Las Vegas Valley shear zone and north of Lake Mead in southern Nevada. Structural and stratigraphic evidence from these sedimentary and associated volcanic rocks suggests that basin development was kinematically related to movement along the Las Vegas Valley ...

A complete transition from frictional slip to ductile shearing flow upon decreasing velocity (or slip rate) or increasing confining pressure is documented for a thin layer of halite undergoing large shearing deformation. The results indicate that the logarithmic law for steady-state friction with a negative velocity dependence breaks down when friction ...

The application of the radial-flow growth chamber to the study of the initial stages of bacterial adhesion to surfaces under flowing conditions is reported. The adhesive properties of the bacterium Pseudomonas fluorescens (NCIB 9046) to stainless steel (type AISI 316) were found to be highly dependent on surface shear stress and the time and concentration of cells used in the ...