Summary
Deformation experiments have been performed in a triaxial compression cell at a temperature of 300°C and confining pressures up to 65 MPa using samples of homogeneous, fresh two-mica-granite (RM) and monzogranite (CM). The cylindrical specimens (d=70 mm, h=140 mm, V=540 cm3) were tested undrained under “dry” (105°C), “as received”, and “water saturated” conditions at deformation rates between\(\dot \varepsilon = 12 \times 10^{ - 6} s^{ - 1} \) and\(\dot \varepsilon = 0.3 \times 10^{ - 6} s^{ - 1} \). The mechanical behaviour of the two types of coarse-grained, crystalloblastic granites is critically influenced by mineralogical composition, porosity, and the amount of intergranular water present in the samples. The failure stress of the CM granite is at about 65% of that of the RM granite; in both rocks strength decreases with increasing porosity and water content.
The presence of interstitial water causes a failure mode of non-localized, homogeneously distributed microcracking in the central parts of the samples, whereas, in runs with dry granites, strain localization along a single shear fracture was observed. When aqueous fluids are present, the macroscopic style of deformation of granites appears to be “ductile” even at lowP andT conditions. Strength and angle of internal friction are reduced to very low values. The style of deformation, as well as the reduction of strength of the water-saturated rock samples, is due to mechanical and chemical effects of intergranular water at elevated temperatures.
The maximum differential stresses measured for these coarse-grained granites are much lower than the strength commonly reported for other granites, e. g. Westerly and Charcoal granites. Our data suggest that the strength of the granitic crust under differential stress is lower than currently deduced from laboratory experiments.
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References
Althaus, E., Bauer, F., Bühler, M., Friz-Töpfer, A., Lempp, Ch., Natau, O. (1989): Deformation granitoider Gesteine bei Temperaturen bis 300°C: Messungen, Beobachtungen und Berechnungen zum Einfluß von äußerem Spannungszustand, Mineralbestand und Gesteinsfluiden. In: Fuchs, K. (ed), Berichtsband 1987–89 SFB 108, Universität Karlsruhe, 697–754.
Atkinson, B. K. (1980): Stress corrosion and the rate-dependent tensile failure of a fine-grained quartz rock. Tectonophysics 65, 281–290.
Atkinson, B. K. (1984): Subcritical crack growth in geological material. J. Geophys. Res. 89, 4077–4114.
Bauer, S. J., Johnson, B. (1979): Effects of slow uniform heating on the physical properties of Westerly and Charcoal Granites. 20th US-Symp. on Rock Mechanics Austin, Texas.
Bauer, S. J., Friedman, M., Handin, J. (1981): Effects of water-saturation on strength and ductility of three igneous rocks at effective pressures to 50 MPa and temperatures to partial melting. In: Proc., 22nd US Symp. Rock Mechanics, Massachusetts Institute of Technology, 79–84.
Brace, W. F., Kohlstedt, D. L. (1980): Limits on lithospheric stress imposed by laboratory experiments. J. Geophys. Res. 85 (B11), 6248–6252.
Carter, N. L., Tsenn, M. C. (1987): Flow properties of continental lithosphere. Tectonophysics 136, 27–63.
Carter, N. L., Andersen, D. A., Hansen, F. D., Kranz, R. L. (1981): Creep and creep rupture of granitic rocks. In: Carter, N. L., Friedman, M., Logan, M. J., Stearns, D. W. (eds), The mechanical behaviour of crustal rocks. AGU Geophys. Monograph 24, 61–82.
Elliot, G. M., Brown, E. T. (1988): Laboratory measurements of the thermohydromechanical properties of rock. Quart. J. Eng. Geol. 21, 299–314.
Evans, J. P. (1988): Deformation mechanisms in granitic rocks at shallow crustal levels. J. Struct. Geol. 10, 437–443.
Evans, B., Fredrich, J. T., Wong, T. F. (1990): The brittle-ductile transition in rocks: recent experimental and theoretical progress. In: Duba, A. G., Darham, W. B., Handin, J. W., Wang, H. F. (eds.), The brittle-ductile transition in rocks—The Heard volume, AGU Geophys. Monograph 56, 1–20.
Friedman, M., Handin, J., Higgs, N. G., Lantz, J. R. (1979): Strength and ductility of four dry igneous rocks at low pressures and temperatures to partial melting. In: Proc., 20th US Symp. Rock Mechanics, Austin, Texas, 35–50.
Ghosh, P. G. (1934): The Carnmenellis granite: its petrology, metamorphism and tectonics. Quart. J. Geol. Soc. London 90, 240–276.
Gretener, P. E. (1981): Reflections on the value of laboratory tests on rocks. In: Garter, N. L., Friedman, M., Logan, J. M., Stearns, D. W. (eds), Mechanical behaviour of crustal rocks. AGU Geophys. Monograph 24, 323–326.
Griggs, D. T. (1967): Hydrolytic weakening of quartz and other silicates. Geophys. J. R. Astron. Soc. 14, 19–32.
Griggs, D. T., Blacic, J. D. (1965): Quartz: anomalous weakness of synthetic crystals. Science 147, 292–295.
Grimm, W. D. (1990): Bildatlas wichtiger Denkmalgesteine der Bundesrepublik Deutschland. Bayer. Landesamt für Denkmalpflege München. Arbeitsheft 50.
Hallam, S. D., Ashby, M. F. (1990): Compressive brittle failure and the construction of multi-axial failure maps In: Barber, D. J., Meredith, P. G. (eds), Deformation processes in minerals, ceramics and rocks. Unwin Hyman, London, 84–108.
ISRM International Society of Rock Mechanics (1983): Commission on standardization of laboratory and field tests. Kovari, K., Tisa, A., Einstein, H. H., franklin, J. A.: Suggested methods for determining the strength of rock materials in triaxial compression: revised version. Int. J. Rock Mech. Min. Sci. 20 (6), 283–290.
IUGS Subcommission on the Systematics of Igneous Rocks (1973): Classification and nomenclature of plutonic rocks. Geol. Newsletter 2, 110–127.
Kronenberg, A., Kirby, S. (1991): Probing the earth's strength: can we measure small stress at high pressure? EOS Trans. AGU 72, 453–454.
Lempp, Ch., Natau, O. (1986): Festigkeitsverhalten von kristallinen Gesteinen unter hohen Drücken und Temperaturen. In: Fuchs, K. (ed), Berichtsband 1984–86 SFB 108, Universität Karlsruhe, 233–278.
Natau, O., Fröhlich, B., Mutschler, Th. (1983): Recent development of large-scale triaxial test. In: Proc., 5th ISRM Congress, Melbourne, Australia, 65–74.
Paterson, M. S. (1978): Experimental rock deformation—the brittle field. Springer, Berlin Heidelberg New York.
Peng, S., Johnson, A. M. (1972): Crack growth and faulting in cylindrical specimens of Chelmsford granite. Int. J. Rock Mech. Min. Sci. 9, 73–86.
Richter, D., Simmons, G. (1974): Thermal expansion behaviour of igneous rocks. Int. J. Rock Mech. Min. Sci. 11, 403–411.
Rutter, E. H. (1986): On the nomenclature of mode of failure transitions in rocks. Tectonophysics 122, 381–387.
Sano, O., Ito, I., Terada, M. (1981): Influence of strain rate on dilatancy and strength of Oshima granite under uniaxial compression. J. Geophys. Res. 86, B10, 9299–9311.
Scholz, Ch. (1988): The brittle-plastic transition and the depth of seismic faulting. Geol. Rdsch. 77 (1), 319–328.
Shimada, M., Cho, A. (1990): Two types of brittle fracture of silicate rocks under confining pressure and their implications in the earth's crust. Tectonophys. 175, 221–235.
Terzaghi, K. (1925): Erdbaumechanik auf bodenphysikalischer Grundlage. Deuticke, reissued Wien, 1976.
Tullis, J. (1990): Experimental studies of deformation mechanisms and microstructures in quartzo-feldspathic rocks. In: Barber, D. J., Meredith, P. G. (eds), Deformation processes in minerals, ceramics and rocks. Unwin Hyman, London, 190–227.
Tullis, J., Yund, R. A. (1977): Experimental deformation of dry Westerly Granite. J. Geophys. Res. 82 (36), 5705–5717.
Tullis, J., Shelton, G. L., Yund, R. A. (1979): Pressure dependence of rock strength: implications for hydrolytic weakening. Bull. Mineral. 102, 110–114.
Wang, H. F., Bonner, B. P., Carlson, S. R., Kowallis, B. J., Heard, H. C. (1989): Thermal stress cracking in granite. J. Geophys. Res. 94 (B2), 1745–1758.
Wong, T. F. (1982): Effects of temperature and pressure on failure and post-failure behaviour of Westerly granite. Mech. Materials 1, 3–17.
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Althaus, E., Friz-Töpfer, A., Lempp, C. et al. Effects of water on strength and failure mode of coarse-grained granites at 300°C. Rock Mech Rock Engng 27, 1–21 (1994). https://doi.org/10.1007/BF01025953
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DOI: https://doi.org/10.1007/BF01025953