It is proposed to carry out conduction thermal modeling of contact metamorphic aureoles with computer algorithms involving numerical (finite difference) simulations of the thermal evolu- tion of intrusives. Variables that we will be considered in this modeling include: shapes of intrusions (both two- dimensional and three-dimensional modeling), initial temperature of the intrusion and country rocks, latent heat of crystalliza- tion of the magma, magma convection, thermal diffusivities of the rocks, and endothermic metamorphic reactions occurring within the aureoles. Contact aureoles containing metapelitic lithologies serve as excellent locales to investigate these thermal processes because mineral thermometers in these rocks provide good constraints on the temperature field. A primary thrust of our proposed research is to apply our conduction modeling to the thermal development of contact aureoles, and to integrate and compare our results with independent thermometry of the intru- sives and aureole rocks. Our preliminary two-dimensional conduction modeling of the Ottawa and Cupsuptic aureoles in Maine shows that our proposed research will yield considerable insight into the nature of intrusives and the surrounding thermal aureoles. For example, our modeling of these aureoles provides constraints on the percentage of crystals initially present in the intrusives. The Skiddaw aureole in the Lake District of England provides an excellent opportunity to evaluate contact metamorphism overlying the roof of an intrusive. Our modeling of this aureole may provide us with additional important insight into the role of convective fluid circulation in he thermal evolution of contact aureoles above intrusives. The proposed modeling of the Strontian aureole in southern Scotland will provide not only an analysis of the thermal evolution of contact metamorphism around a "mushroom-shaped" intrusion floored by metamorphic rocks, but also improved insight into Lasaga's (1986) provocative kinetic interpretation of the second sillimanite isograd in the Strontian aureole.
