Report of a meeting of the Metamorphic Studies Group held at Burlington House, on 5 March, 1986. The meeting was organized by K. H. Brodie.
A Metamorphic Studies Group meeting on Metamorphic studies: research in progress and the fifth Annual General Meeting of the Group were held on 5 March 1986. Fifteen papers were presented, including four from overseas speakers. For the first time this year the talks included one invited overseas speaker, Professor W. L. Griffin from the Mineralogisk-Geologisk Museum in Oslo, who presented a review of high pressure metamorphism in Western Norway.
The morning session was chaired by Stephen Daly, and concentrated on the topical theme of the role of fluids in metamorphism. B. Yardley started the session with a joint paper with S. Bottrell considering the important effects that fluid immiscibility may have in natural metamorphism, particularly at low grades. In particular, in a two-phase system the relative permeability may become very low for a phase of low proportions. This may have the effect concentrating, for example, NaCl in the fluid phase. K. W. Burton then considered the effects of fluid composition on surface energy, using metamorphic sector zoning as an example. Increasing surface energy increases the overstepping of an equilibrium boundary, leading to fewer nuclei which will tend to grow relatively large. In the garnets investigated, inclusions, were found to be rich in CO2, H2O (plus N+Ar), and it was suggested that quartz intergrowths commonly develop as a result of low