منزل •the crack seal mechanism of rock deformation

the crack seal mechanism of rock deformation

  • An unusual 'crack--seal' vein geometry

    A. 1983. Crack-seal fibre growth mechanisms and their significance in the development of oriented layer-silicate microstructures. Tectonophysics, 92, 147-170. Dietrich, D. & Ramsay, J. 1980. Opening processes of veins from the Helvetic nappes (Abstr.). International Conference on the Effect of Deformation on Rocks.

  • Fracture mechanics of rocks (Book) | OSTI.GOV

    The GRC on Rock Deformation highlights the latest research in brittle and ductile rock mechanics from experimental, field and theoretical perspectives. The conference promotes a multi-disciplinary forum for assessing our understanding of rock strength and related physical properties in the Earth.

  • Estimation of cracking and damage mechanisms in rock under ...

    The crack motion vector l and crack normal vector n, as well as the failure mechanism of cracks, can be derived from the moment tensor analysis as mentioned in Section 4.1. In this study, the directions of the crack faces were also calculated from the directions of the crack normal vectors.

  • Rock Mechanics - an introduction for the practical engineer

    Rock Mechanics 5 The original and modified Griffith theories, when expressed in terms of the stresses at fracture5, contribute little to the understanding of rock fracture under dynamic stress conditions, the energy changes associated with fracture or the deformation process of

  • `Crack–seal', slip: a new fault valve mechanism ...

    The crack–seal mechanism of rock deformation. Nature, 284 (1980), pp. 135-139. CrossRef View Record in Scopus Google Scholar. Rispoli, 1981. R. Rispoli. Stress fields about strike–slip faults inferred from stylolites and tension gashes. Tectonophysics, 75 (1981), pp. T29-T36.

  • Crack-seal patterns: records of uncorrelated stress ...

    Abstract: Statistical properties of crack-seal veins are investigated with a view to assessing stress release fluctuations in crustal rocks. Crack-seal patterns correspond to sets of successive parallel fractures that are assumed to have propagated by a subcritical crack mechanism in …

  • Crack-seal patterns: records of uncorrelated stress ...

    Crack-seal patterns correspond to sets of successive parallel fractures that are assumed to have propagated by a subcritical crack mechanism in the presence of a reactive fluid. They represent a time-sequence record of an aseismic and anelastic process of rock deformation.

  • Gold, Mining and Prospecting: The Geology of Hydrothermal ...

    One thing about crack seal things they tend to form quite rapidly during the deformation of the rocks by precipitation of minerals within the fractures. Geologists feel that this happens quite swiftly when measured in geological time, because pressures and deformation mean there are large open spaces that cannot be maintained.

  • Fracture and Brittle Deformation

    The brittle regime is where the physical conditions promote brittle deformation mechanisms such as frictional sliding along grain contacts, grain rotation and grain ... • Microscopic cracks, pores and other flaws weaken rocks ... Deformation bands and fractures in porous rocks Deformation bands are mm -thick zones of localized compaction ...

  • Stylolites and crack-seal e - UiO

    deform ed below the tectonically emplaced Caledonian Laksefjord Nappe. The rocks contain stylolite seams, crackseal veins, and conjugate shear surfaces, suggesting that deformation took place largely by pressure solution, Iocal transport, and redeposition of quartz. An X : Z strain ratio of approximately 1.25 was achieved by this mechanism.

  • Mechanisms of Fatigue Crack Initiation and Growth

    nucleating and growing a fatigue crack to a length at which it can be detected.! The range of effective stress intensity factor, that is, the idea of crack closure allows the growth of fatigue cracks to be rationalized.! The behavior of small cracks is in many respects quite different from long cracks.

  • A case study on large deformation failure mechanism of ...

    Failure mechanism analysis of the large deformation. The failure mechanism of the main ventilation roadway under the primary support scheme had the following characteristics: 1) Contradiction between high in situ stress and low-strength rock. The + 535 m main ventilation roadway was located at a 700 m depth with relatively higher underground ...

  • Research on Control Mechanism of Surrounding Rock of Deep ...

    To address the large deformation of the surrounding rock of deep gob-side entry retaining under high stress, lithological characteristics of the surrounding rock and failure model of support body and their evolutionary processes are analyzed through field investigation and theoretical analysis. Failure mechanisms of surrounding rock and the technology to control it are studied …

  • Development of a Mechanical Crack Model to Analyze ...

    Rock contains discontinuities at all scales. These discontinuities make rock behave in a complex way. This paper discusses a new approach to underground design based on the theory of rock fracture mechanics. The mechanism of deformation and failure of coal was studied by observing the distributions of length, orientation and spacing of the pre-existing as well as stress-induced cracks.

  • Mechanisms of Fracture and Friction of Crustal Rock B. K ...

    rocks, modelling earthquake rupture, the stability of hot, dry rock geothermal reservoirs, stimulation of oil and gas reservoirs, the crack-seal mechanism of rock deformation and low stress dilatancy, fracture mechanics of lunar rocks, magmatic intrusions and the relaxation of internal stresses in rock.

  • Extension fracture propagation in rocks with veins ...

    rock, fractures tend toforminthe hostrock.Repeated fractur-ing and sealing can produce sets of parallel microveins with single veins reflecting the aperture of a single fracture event. This mechanism is known as the crack-jump mechanism [Caputo and Hancock, 1999]. [11] The strength ratios in the system depend on the one

  • The evolution of crack seal vein and fracture networks in ...

    Common microstructural features of the crack seal mechanism are host rock inclusion bands, stretched crystals, and fibrous crystals [Cox and Etheridge, 1983; Fisher and Brantley, 1992; Bons, 2001; Hilgers and Urai, 2002]. Repeated delocalized fracturing of a veined rock is called crack jump [Caputo and Hancock, 1999]. It produces bundles of ...

  • Vein (geology) - Wikipedia

    This process is known as the crack-seal mechanism. Crack-seal veins are thought to form quite quickly during deformation by precipitation of minerals within incipient fractures. This happens swiftly by geologic standards, because pressures and deformation mean that large open spaces cannot be maintained; generally the space is in the order of ...

  • The crack–seal mechanism of rock deformation | Semantic ...

    The crack–seal mechanism of rock deformation. Many naturally deformed crustal rocks contain mineral-filled extension veins. The crystals making up the vein filling often show a fibrous habit and seem to be built up by a succession of 'crack–seal' increments: the elastically deforming rock fails by fracture, and the walls of the open ...

  • Auriferous lode of Hira-Buddini gold mine, Hutti-Maski ...

    Crack-seal process appears to be the mechanism of vein formation. The microstructures of the vein minerals indicate a temperature of ~500ºC during the vein emplacement. In the auriferous lode, amphibolite and felsic metavolcanic rock have been subjected to intense alteration by the ore fluid with development of biotite-chlorite-tourmaline ...

  • Crack-seal fibre growth mechanisms and their significance ...

    Repeated crack-seal increments build up a fibrous microstructure. 149 MECHANISMS OF FIBRE GROWTH DURING CRACK-SEAL DEFORMATION The growth of fibres from a supersaturated solution during crack-seal deforma- tion can be considered in terms of three stages: (a) Nucleation or initial growth on microfracture walls after the initial cracking increment.

  • Vein (geology) - Infogalactic: the planetary knowledge core

    Crack-seal veins When the confining pressure is too great, or when brittle - ductile rheological conditions predominate, vein formation occurs via crack-seal mechanisms. This happens swiftly by geologic standards, because pressures and deformation mean that large open spaces cannot be maintained; generally the space is in the order of ...

  • A microstructural study of a "crack-seal" type serpentine ...

    The banded internal structure and the filling along the vein-wall contact suggest a crack-seal mechanism of formation. Each crack is homogeneously filled with chrysotile and some rare polygonal serpentines (tubular serpentine varieties) and disseminated patches of gel-type protoserpentine.

  • 19 th International Conference on Deformation Mechanisms ...

    solid crack-seal inclusion bands were identified. Adjacent fibres share smooth grain boundaries with each other and reveal accumulations of dust rims along the edges. During subsequent deformation, these veins acted as competent objects in a weak matrix, showing buckling, folding and …

  • Mechanisms of Continuous Deformation | SpringerLink

    Abstract. Continuous deformation can result from elementary mechanisms taking place at the scale of a single crystal. Under directed (deviatoric) external stress, a single crystal can deform by gliding upon reticular planes, this is plastic deformation in a strict sense, by directional diffusion of atoms through the crystal lattice or along its faces, or by direct crystallization of a new ...

  • Kinetics of crack-sealing, intergranular pressure solution ...

    Kinetics of crack-sealing, intergranular pressure solution, and compaction around active faults Franc°ois Renarda,*, Jean-Pierre Gratierb, Bjørn Jamtveita aFluid–Rock Interactions Group, University of Oslo, Departments of Geology and Physics, P.O. Box 1047 Blindern, 0316 Oslo, Norway bLGIT, CNRS-Observatoire, Universite´ Joseph Fourier BP 53, 38041 Grenoble cedex, France

  • 17. STRUCTURAL EVOLUTION OF UPPER LAYER 2, HOLE 896A1

    by the crack-seal mechanism (i.e., incremental growth of fibers dur-ing cyclic hydrofracturing; Agar, 1990; Tartarotti et al., this volume). Breccias in DSDP and ODP drill cores from the upper ocean crust have generally been considered to have formed on the seafloor as sedimentary accumulations or hyaloclastites, but the characteristics

  • Lecture 5b - tectonique.net

    The crack-seal mechanism ( Ramsay 1980) is the favoured mechanism for about all veins with elongate crystals. In this model growth occurs in many repeated small increments: crack-seal events: Crack event -> opening of narrow open crack, filled with fluid. Seal event -> Precipitation fills (=seals) the crack again.

  • The evolution of crack seal vein and fracture networks in ...

    relativeorientationof the veinto fracturing andthe relativestrength ofhost rock and vein,the modelsshow a variety of fracture behaviors: in weak veins, fractures localize within the vein material. This behavior is well described in literature as the crack seal mechanism [Ramsay, 1980]. …