Exhumation paths of high-pressure metapelites obtained from local equilibria for chlorite-phengite assemblages

Abstract

The compositional variation of phengite and chlorite pairs in rocks sampled across the metamorphic zonation of three different blueschist belts (Cycladic, Sambagawa and Schistes Lustrés) is characterized from the regional to the thin-section scale. The different sample suites show different compositional trends, but similar trends are observed at the regional and thin-section scale in the same unit. At the thin-section scale, several local chlorite-phengite equilibria involving minerals of different compositions can be identified. These observations suggest that at temperature T