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The dynamics of convection and the mechanical behavior of the lithosphere are controlled by the rheology of upper mantle rocks. For this reason, experimental and theoretical studies on the rheology of olivine aggregates have been fields of active research for at least the last 35 years. In this short-course paper, I briefly review some experimental and theoretical constraints on the rheology of upper mantle rocks and minerals and then discuss the application of these data for understanding the rheology of the upper mantle in different tectonic environments. There is an expansive literature on the subject of mantle rheology; extensive reviews and background can be found in several recent articles and books (Poirier 1985; Ranalli 1995; Karato and Wu 1993; Kohlstedt et al. 1995; Drury and FitzGerald 1998; Hirth and Kohlstedt 2003), as well as numerous references made throughout this chapter.
I focus the discussion of this chapter on the application of experimental data for constraining the rheology of the oceanic lithosphere and mantle. Constraints on mantle rheology based on extrapolation of laboratory experiments to deformation conditions in the oceanic lithosphere and asthenosphere are illuminating for several reasons. First, the composition of the mantle is relatively well constrained by analyses of peridotites from ophiolites and mid-ocean ridges, as well as chemical analyses of basalts. Second, the oceanic lithosphere is comprised of rock that cooled from high temperature conditions at high pressure, and is therefore not previously fractured. In this way the lithosphere is similar to the “ideal” rocks we use in our experiments. Third, the temperature of the lithosphere is constrained by a number of geophysical observations. Fourth, microstructural observations on naturally deformed mantle rocks justify applying experimental flow laws at geologic conditions. Finally, several independent geophysical observations, such as constraints on viscosity based on analysis …