On Mechanisms and Kinetics of Creep by Intergranular Pressure Solution

Abstract

Since the earliest work on pressure solution (Sorby, 1863), numerous papers on the subject have appeared in the literature and it is well established that polycrystalline materials containing a solution or partial melt phase within grain boundaries can deform by a process of fluid assisted diffusional creep or intergranular pressure solution creep (Durney, 1972; Stocker and Ashby, 1973; Robin, 1978; Raj, 1982; Pharr and Ashby, 1983; Rutter, 1983; Cooper and Kohlstedt, 1984). This is believed to be distinct from solid state diffusion creep in which grain boundary self diffusion can potentially be (modestly) enhanced by the presence of water defects in the grain boundary zone. In nature, aside from the development of larger-scale solution transfer features such as stylolites and solution cleavages (Kamb, 1959, 1961; Merino and Ortoleva, 1980; Ortoleva et al., 1982; Merino et al., 1983; Dewers and Ortoleva, 1989, 1990; Merino, 1992), pervasive intergranular pressure solution is an important deformation mechanism, manifested by many types of partially dissolved objects such as grains and fossils (Elliot, 1973; Rutter, 1976). It occurs under conditions ranging from diagenetic to greenschist facies (Weyl, 1959; Elliot, 1973; Beach, 1979; Etheridge et al., 1983; Rutter, 1983; Tada et al., 1987; Tada and Siever, 1989). In the diagenetic regime, intergranular pressure solution creep is one of the main mechanisms for compaction and cementation of porous sedimentary rocks (e.g., Tada et al., 1987). In pelitic rocks, it appears to be the dominant deformation mechanism up to medium and even high grade metamorphic conditions (Bell and Cuff, 1989).