Fault rocks and fault mechanisms
Tóm tắt
Physical factors likely to affect the genesis of the various fault rocks—frictional properties, temperature, effective stress normal to the fault and differential stress—are examined in relation to the energy budget of fault zones, the main velocity modes of faulting and the type of faulting, whether thrust, wrench, or normal. In a conceptual model of a major fault zone cutting crystalline quartzo-feldspathic crust, a zone of elastico-frictional (EF) behaviour generating random-fabric fault rocks (gouge—breccia—cataclasite series—pseudotachylyte) overlies a region where quasi-plastic (QP) processes of rock deformation operate in ductile shear zones with the production of mylonite series rocks possessing strong tectonite fabrics. In some cases, fault rocks developed by transient seismic faulting can be distinguished from those generated by slow aseismic shear. Random-fabric fault rocks may form as a result of seismic faulting within the ductile shear zones from time to time, but tend to be obliterated by continued shearing. Resistance to shear within the fault zone reaches a peak value (greatest for thrusts and least for normal faults) around the EF/QP transition level, which for normal geothermal gradients and an adequate supply of water, occurs at depths of 10–15 km.
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Tài liệu tham khảo
Ambraseys N. N.Maximum intensity of ground movements caused by faultingProc. 4th Wld. Conf Earthq Engng1969115471Santiago
Anderson E. M.The dynamics of faulting19512nd edEdinburghOliver & Boyd
Berry F. A. F.High fluid potentials in the California Coast Ranges and their tectonic significanceBull Am Assoc Petrol Geol197357121949
Birch F., Judd W. R.Megageological considerations in rock mechanicsState of stress in the earth’s crust1964New YorkElsevier5580
Carslaw H. S., Jaeger J. C.Conduction of heat in solids19592nd edOxfordClarendon Press
Christie J. M.The Moine Thrust in the Assynt region, north-west ScotlandUniv Calif Publs geol Sci196340345419
Dieterich J. H., Donath F. A.Earthquake mechanisms and modellingAnnual review of earth and planetary science19742Palo Alto, CalifAnnual Reviews Inc275301
Francis P. W., Sibson R. H., Park R. G., Tarney J.The Outer Hebrides ThrustThe early Precambrian of Scotland and related rocks of Greenland1973Univ. of Keele95104
Griffith A. A. 1924. Theory of rupture. Proc. 1st Int. Congr. appl. Mech. Delft 55–63.
Griggs D. T., Baker D. W.The origin of deep-focus earthquakesProperties of matter under unusual conditions1969New YorkInterscience2342
Griggs D. T., Handin J.Observations on fracture and an hypothesis for earthquakesMem geol Soc Am19607934764
Heard H. C.Comparison of flow properties of rocks at crustal conditionsPhil. Trans. R. Soc. Lond1976A28317386
Higgins M. W.Cataclastic rocksProf. Pap. U.S. geol. Surv1971687
Hsu K. J.Granulites and mylonites of the region about Cucamonga and San Antonio Canyons, San Gabriel Mountains, CaliforniaUniv Calif Publs, geol Sci195530223352
Jaeger J. C., Cook N. G. W.Fundamentals of Rock Mechanics1969LondonMethuen
Jeffreys H.The Earth19594th edCambridge Univ. Press
Kerrich R. F. 1974. Aspects of pressure solution as a deformation mechanism. Thesis Ph.D. Univ. London (unpubl.).
Lapworth C.The highland controversy in British geology; its causes, course and consequenceNature, Lond1885325589
McClintock F. A. & Walsh J. B. 1962. Friction on Griffith cracks under pressure. Proc. 4th US. Natl. Congr. appl. Mech. 1015–21.
Mogi K., Donath F. A.Rock fractureAnnual review of earth and planetary science19731Palo Alto. CalifAnnual Reviews Inc6384
Orowan E.Mechanism of seismic faultingMem geol Soc Am19607932345
Press F., Brace W. F.Earthquake predictionScience NT1966152157584
Price N. J.Fault and joint development in brittle and semi-brittle rock1966LondonPergamon
Price N. J., Hancock P. L.Development of fracture cleavage and kindred structuresInt geol Congr1972358492
Pshennikov K. B.The energy balance in the focal region of a strong earthquakeIzv Acad Sci USSR, Phys Solid Earth1965101724
Reid H. F.The mechanics of the earthquakeIn, The California earthquake of April 18, 19061910Washington D.CCarnegie Institution of WashingtonReport of the State Investigation Commission, Part 2, 16–28
Righter C. F.Elementary Seismology1958San FranciscoFreeman
Rutter E. H.The kinetics of rock deformation by pressure solutionPhil. Trans. R. Soc. Lond1976A28320319
Spry A.Metamorphic Textures1969LondonPergamon
Turner F.J.Metamorphic petrology1968New YorkMcGraw-Hill
White S.The effects of strain on the microstructures, fabrics and deformation mechanisms in quartzitePhil. Trans. R. Soc. Lond1976A2836986