Skip to main content Accessibility help

On the Triggering of Shear Faults During Brittle Compressive Failure: A New Mechanism

  • E. M. Schulson (a1), D. Iliescu (a2) and C. E. Renshaw (a3)


Direct observations are presented of the micromechanical events that contribute to the localization of deformation within brittle compressive shear faults. The observations were made on ice and show that faults are composed of both wing cracks and splay cracks. The latter features initiate from one side of inclined parent cracks and create sets of slender microcolumns fixed on one end and free on the other. It is proposed that the fault-triggering mechanism is the breaking of near-surface microcolumns owing to frictional sliding across their free ends. A lower-bound estimate of the compressive strength of ice is found to be in order of magnitude agreement with experiment.



Hide All
1. Schulson, E.M., The structure and mechanical behavior of ice, J.O.M. (1998 in press).
2. Schulson, E.M., Iliescu, D. and Renshaw, C.E., On the initiation of shear faults during brittle compressive failure: A new mechanism, J. Geophys. Res. (1998 in press).
3. Wong, T.-F., Micromechanics of faulting in Westerly granite, Int. J. Rock Mech. Min. Sci. & Geomech. Abstr., 19, 4964 (1982).
4. Martel, S.J. and Pollard, D.D., Mechanics of slip and fracture along small faults and simple strike-slip fault zones in granitic rock, J. Geophy. Res., 94, 94179428 (1989).
5. Ashby, M.F. and Hallam, S.D., The failure of brittle solids containing small cracks under compressive stress states, Acta. metall., 34, 497510 (1986).
6. Schulson, E.M., Kuehn, G.A., Jones, D.E. and Fifolt, D.A., The growth of wing cracks and the brittle compressive fracture of ice, Acta metall. mater., 39, 26512655 (1991).
7. Cooke, M.L., Fracture localization along faults with spatially varying friction, J Geophys. Res., 102, B10, 24,425-22,434 (1997).
8. Reches, Z. and Lockner, D.A., Nucleation and growth of faults in brittle rocks, J. Geophys. Res., 99, B9, 18,159-18,173 (1994).
9. Thouless, M.D., Evans, A.G., Ashby, M.F. and Hutchinson, J.W., The edge cracking and spalling of brittle plates, Acta metall., 35, 13331341 (1987).
10. Schulson, E.M., , E.M. and Hibler, W.D. III, The fracture of ice on scales large and small: arctic leads and wing cracks, Journal of Glaciology, 37, 319322 (1991).
11. Gottschalk, R.R., Kronenberg, A.K., Russel, J.E., and Handin, J., Mechanical anisotropy of gniess: Failure criterion and textural sources of directional behavior, J. Geophys. Res., 95, 613-21,634 (1990).
12. Segall, P. and Pollard, D.D., Nucleation and growth of strike-slip faults in granite, J Geophys. Res., 88, 555568 (1983).
13. Cruikshank, Z.M., Zhao, G. et al. , Analysis of minor fractures associated with joints and faulted joints, J. Struct. Geol., 13, 865886 (1991).
14. Conrad, R.E. II, and Friedman, M., Microscopic feather fractures in the faulting process, Tectonophysics, 33, 187198 (1976).
15. Davies, R.K. and Pollard, D.D., Relations between left-lateral strike-slip faults and right-lateral kink bands in granodiorite, Mt. Abbot Quadrangle, Sierra Nevada, California, Pure & Appl. Geophys., 124, 177201 (1986).
16. Moore, D.E. and Lockner, D.A., The role of microcracking in shear-fracture propagation in granite, J. Struct. Geol., 17, 95114 (1995).


Full text views

Total number of HTML views: 0
Total number of PDF views: 0 *
Loading metrics...

Abstract views

Total abstract views: 0 *
Loading metrics...

* Views captured on Cambridge Core between <date>. This data will be updated every 24 hours.

Usage data cannot currently be displayed