Evidence of Fluid Phase Behaviour and Controls in the Intrusive Complex and Its Aureole

This chapter brings together evidence pertaining to the presence, composition, influence and mobility of fluids rich in volatile species (principally H₂O and CO₂) in the development of the Ballachulish intrusive complex and its aureole. We examine fluid-mineral-rock interactions over the complete range of scales from that of the small-scale systems represented by individual rocks, to that of the large-scale system represented by the combined intrusive complex and its aureole. This will allow comparison with models of fluid behaviour identified in other low- to high-grade metamorphic situations (see reviews in Walther and Wood 1986; and Valley 1986), such as the hydrothermal circulation system of the Hebridean intrusive complexes (Taylor and Forester 1971; Forester and Taylor 1977), and the high fluid-pressure model of regional metamorphism in orogenic belts (Etheridge et al. 1983, 1984).