Contributions to Mineralogy and Petrology

, Volume 65, Issue 2, pp 183–190 | Cite as

Local modification of rock chemistry by deformation

  • R. Kerrich
  • W. S. Fyfe
  • B. E. German
  • I. Allison


Metabasalts subjected to progressive deformation in large-scale shear zones at Yellowknife display corresponding changes in major element abundances. Deformation, under conditions of greenschist facies metamorphism, has involved grain size reduction from 1200 μm to <20 μm, depletion of SiO2 (≃5%) and Na2O, together with hydration, and a decrease in specific gravity from 2.97 to 2.80. Chemical redistribution by deformation has been accomplished through a decrease in grain diameter of quartz and albite by intercrystalline diffusive mass transport (pressure solution), with concomitant transfer of material into extension veins. The degree of chemical modification is related to the finite strain. Deformation has involved a redistribution of ∼7.1015g of SiO2 over a volume of about 50km3.

The microstructure of an adamellite deformed in a shear zone at higher temperature, under conditions of amphibolite facies metamorphism is indicative of dominant dislocation creep. A low degree of tectonic grain refinement is present. Constant values of major element abundances and specific gravity determined across the shear zone at increasing states of strain imply isochemical and isovolumetric deformation. These results are taken to support the precept that crustal deformation is characterised by a low temperature deformation regime dominated by pressure solution, with local changes of rock chemistry and volume; and a high temperature regime in which strain is accommodated principally by dislocation creep, an isochemical and isovolumetric deformation mechanism.


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. Allison, L, Ramsay, J.G.: Structural analysis of shear zones in a deformed granite from the Pennine Zone, Swiss Alps. Schweiz. Mineral. Petrog. Mitt, (in press, 1977)Google Scholar
  2. Ashby, M.F.: A first report on deformation-mechanism maps. Acta Met. 20, 887–897 (1972)Google Scholar
  3. Babcock, R.S.: Computational models of metasomatic processes. Lithos 6, 279–290 (1973)Google Scholar
  4. Bathurst, R.G.C.: Carbonate sediments and their diagenesis. Amsterdam: Elsevier 1971Google Scholar
  5. Beach, A.: A geochemical investigation of pressure solution and the formation of veins in deformed greywacke. Contrib. Mineral. Petrol. 41, 61–68 (1974)Google Scholar
  6. Beach, A.: The interrelations of fluid transport, deformation, geochemistry and heat flow in early Proterozoic shear zones in the Lewissian complex. Phil. Trans. Roy. Soc. London, Ser. A 280, 569–604 (1976)Google Scholar
  7. Bowen, N.L.: The evolution of the igneous rocks. Princeton: Princeton University Press 1928Google Scholar
  8. Boyle, R.W.: The geology, geochemistry and origin of the gold deposits of the Yellowknife district. Mem. Geol. Surv. Canada 310 (1961)Google Scholar
  9. Breakey, A.R.: A mineralogical study of the gold-quartz lenses in the Campbell shear, Con Mine, Yellowknife, N.W.T. M.Sc. thesis, McGill University (1975)Google Scholar
  10. Bryan, W.B., Finger, L.W., Chayes, F.: Estimating proportions in. petrographie mixing equations by least squares approximation. Science 163, 926–927 (1969)Google Scholar
  11. Coble, R.L.: A model for boundary diffusion controlled creep in polycrystalline materials. J. Appl. Phys. 34, 1979–1982 (1963)Google Scholar
  12. Durney, D.: Deformation history of the Western Helvetic Nappes, Valais, Switzerland. Unpub. Ph. D. thesis, Imperial College, Univ. of London (1972)Google Scholar
  13. Elliott, D.: Diffusional flow laws in metamorphic rocks. Geol. Soc. Am. Bull. 84, 2645–2664 (1972)Google Scholar
  14. Fyfe, W.S.: Geochemistry. Oxford: Oxford University Press 1974Google Scholar
  15. Fyfe, W.S.: Chemical aspects of rock deformation. Phil. Trans. Roy. Soc. London, Ser. A 283, 221–228 (1976)Google Scholar
  16. Gray, N.H.: Estimation of parameters in petrologic materials balance of equations. Math. Geol. 5, 225–236 (1973)Google Scholar
  17. Gresens, R.L.: Composition-volume relations of metasomatism. Chem. Geol. 2, 47–65 (1966)Google Scholar
  18. Henderson, J.F., Brown, I.C.: Geology and structure of the Yelllowknife Greenstone Belt, District of Mackenzie. Geol. Surv. Canada Bull. 141, (1966)Google Scholar
  19. Kerrich, R.: An historical review and synthesis of research on pressure solution. Zentr. Geologie u. Paläontologie (in press, 1977)Google Scholar
  20. Kerrich, R., Beckinsale, R.D., Durham, J.J.: The transition between deformation regimes dominated by intercrystalline diffusion and intracrystalline creep evaluated by oxygen isotope thermometry. Tectonophysics 38, 241–257 (1977b)Google Scholar
  21. Kerrich, R., Fyfe, W.S., Allison, I.: Iron reduction around goldquartz veins, Yellowknife District, N.W.T., Canada. Econ. Geol. 72, 657–663 (1977a)Google Scholar
  22. Mossop, G.D.: Origin of the peripheral rim, Redwater Reef, Alberta. Bull. Can. Petrol. Geol. 20, 238–280 (1972)Google Scholar
  23. Raj, R., Ashby, M.F.: On grain boundary sliding and diffusional creep. Metall. Trans. 2, 1113–1127 (1971)Google Scholar
  24. Ramsay, J.G.: Folding and fracturing of rocks. New York: McGraw-Hill 1967Google Scholar
  25. Ramsay, J.G., Graham, R.H.: Strain variation in shear belts. Can. J. Earth Sci. 7, 786–813 (1970)Google Scholar
  26. Rutter, E.H.: The kinetics of rock deformation by pressure solution. Phil. Trans. Roy. Soc. London, Ser. A283, 203–219 (1976)Google Scholar
  27. Sorby, H.C.: On the direct correlation of mechanical and chemical forces. Proc. Roy. Soc. 12, 538–550 (1863)Google Scholar
  28. Spry, A.: Metamorphic Textures. Oxford: Pergamon 1969Google Scholar
  29. Stephansson, O.: Stress-induced diffusion during folding. Tectonophysics 22, 233–251 (1974)Google Scholar
  30. Stocker, R.L., Ashby, M.F.: On the rheology of the upper mantle. Rev. Geophys. Space Phys. 11, 391–426 (1973)Google Scholar
  31. Voll, G.: New work on petrofabrics. Liverpool Manchester. Geol. J. 2, 503–567 (1960)Google Scholar
  32. Weyl, P.K.: Pressure solution and the force of crystallisation — a phenomenological theory. J. Geophys. Res. 62, 2001–2025 (1959)Google Scholar
  33. White, S.: The dislocation structures responsible for the optical effects in some naturally deformed quartzes. J. Mater. Sci. 8, 490–499 (1973)Google Scholar
  34. White, S.: The effects of strain on the microstructures, fabrics and deformation mechanisms in quartzites. Phil. Trans, Roy. Soc. London, Ser. A283, 69–86 (1976)Google Scholar
  35. Williams, P.F.: Development of metamorphic layering and cleavage in low grade rocks at Bermagui, Australia. Am. J. Sci. 272, 1–47 (1972)Google Scholar
  36. Wright, T.L., Doherty, P.C.: A linear programming and least squares computer method for solving petrologic mixing problems. Bull. Geol. Soc. Am. 81, 1995–2008 (1970)Google Scholar

Copyright information

© Springer-Verlag 1977

Authors and Affiliations

  • R. Kerrich
    • 1
  • W. S. Fyfe
    • 1
  • B. E. German
    • 1
  • I. Allison
    • 1
  1. 1.Department of GeologyUniversity of Western OntarioLondonCanada

Personalised recommendations