The proposed research addresses the role of burial depths, uplift rates, and thermal parameters as controls on large-scale patterns of mineral equilibria in classic metamorphic terranes in Vermont and New Hampshire. Also, it is proposed that regional variations in thermal properties of the crust are required to explain the complicated variations in pressures (burial) and temperatures inferred for rocks in this region. Combined field and theoretical studies will be carried out to evaluate this hypothesis. Specifically, detailed studies will evaluate metamorphic pressure, cooling rates near peak metamorphism, and effects of lateral heat transfer to determine the relative roles of he above three parameters on distribution of mineral isograds. Timing of metamorphism will be determined by geochronological methods to understand the connection between tectonic and metamorphic history.