The continuum theory of mixtures provides a framework around which present knowledge of sugblacial till can be organized. The proposed framework is provisional in two senses: the constitutive description of till will require improvement, and not all potentially processes have been included. Till is treated as a three-component mixture of water, clasts (coarse-gained solids), and fine-grained matrix solids. These components obey mass balance equations, and their behavior is subject to constitutive relations that describe such processes as Darcian water transport, fine-grained sediment transport, consolidation, shear defoemation, delatancy, and comminution. Five state variables uniquely determine the compessibility, permeability, shear strength, and other physical properties. Numerical solutios of the state evolutions equations illustrate that the propeties of till are highly responsive to changes in the subglacial environment ¿ American Geophysical Union 1987