The intrusion of the Etive igneous complex, one of the Caledonian 'Newer Granites', into Dalradian metasediments of SW Grampian Highlands during the Devonian caused contact metamorphism, producing a thermal aureole up to 2 km wide. The thermal aureole is well developed in the southern segment of the aureole, adjacent to the Quarry Diorite ring dyke. Pelites and semi-pelites in the upper Spl Zone and Sill Zone underwent partial melting. The vein-like form of many leucosomes suggest that partial melting was accompanied by brittle fracturing.
Thermodynamic estimates yield a pressure of ca.
Water contents of cordierite were employed to work out the water activities during metamorphic reactions and partial melting. None of the cordierites from the aureole contains any detectable CO 2 . Within-sample variation is low, indicating a close approach to equilibrium. These results indicate that there was no significant infiltration of magmatic fluids from the crystallising Quarry Diorite laterally into the wall-rocks of the pluton during contact metamorphism.