Diffusion Data in Silicate Melts

Abstract

Atomic scale diffusion in silicate melts plays a critical role in a variety of magmatic processes, as long recognized by geologists (Bowen 1921). Geochemists have investigated diffusion in silicate melts (including stable liquids and supercooled liquids and glasses) using a variety of methods as micro-analytical tools becoming available (e.g., Medford 1973; Jambon and Carron 1976; Magaritz and Hofmann 1978a,b; Hofmann 1980; Shimizu and Kushiro 1984; Zhang et al. 1991a; Koepke and Behrens 2001; Saal et al. 2008). The investigations were aimed at understanding the mechanisms of diffusion, the effect of temperature, pressure, H2O content, f O2, and more generally melt composition on the diffusivities, and to measure the diffusivity values for geological applications. A large database is now available. This chapter reviews diffusion data relevant to magmatic systems. The large body of literature on diffusion in simple-system melts, of interests to glass and ceramic scientists, is not included in this review, nor are the calculated diffusivities from ab initio and molecular dynamics methods. This review covers literature diffusion data (except multicomponent diffusion matrix data, and those of H, C, O and noble gases) in multicomponent silicate melts (the term melts as used in this chapter also includes glasses), including melts with mineral compositions and including glasses. This chapter complements the other chapters on diffusion in silicate melts, which cover H, C and O diffusion (Zhang and Ni 2010, this volume), noble gas diffusion (Behrens 2010, this volume), theories and models of self and tracer diffusion (Lesher 2010, this volume), and multicomponent diffusion (Liang 2010, this volume). We have compiled experimental data on self, tracer and effective binary diffusion in Online Supplementary Table 1 (found at http://www.minsocam.org/MSA/RIM ), with about 3600 entries of individual diffusivity …