• stress-strain;
  • end-point memory;
  • congruence;
  • elastic after-effect;
  • Preisach

[1] The earliest reported observations of hysteresis in rocks were published at the beginning of the last century. In analogy with magnetic systems, a Preisach model was adapted in the early 1980s and used to describe the elastic hysteresis in rocks. In spite of its apparent success, as with any model of a physical process, use of the Preisach model has limitations that need to be carefully considered. Several new stress-strain measurements on various sedimentary rocks are reported here to probe the limits of the Preisach model. “Quasistatic” stress-strain measurements shown here explore in detail some of the predictions of this model, namely end point memory and congruence but also demonstrate the impact of elastic aftereffect (or relaxation). It was found, for example, that at certain stress-strain measurement rates for Berea sandstone, elastic after-effect/relaxation effects dominate, hysteresis loops completely vanish, the Preisach model fails, and simple nonlinear behavior remains.