Illustrations of the 15 cm thick layer of garnet-kyanite micaschist sampled as P03-9 (location in Fig. 4). (a) Field view (Grt, garnet; sb, shear band). (b) Photomicrograph centered on a garnet porphyroclast. Arrows highlight the orientation of the main set of fractures within the clast, some being filled with biotite; dp, iron oxide-enriched dissolution planes. (c–e) BSE images illustrating the relations between monazite grains and adjacent minerals in the schistosed matrix. (f) Yttrium X-ray map of the aggregate visible in Figure 7e and a report of the ²⁰⁸Pb/²³²Th ages obtained by LA-ICPMS dating, highlighting the existence of two generations of monazite. Ages in italics correspond to pits yielding discordant ²⁰⁶Pb/²³⁸U–²⁰⁷Pb/²³⁵U ages; together with data from other grains, these ages define a linear trend in a Tera-Wasserburg diagram and yield a lower-intercept age of 36.3 ± 1.5 Ma for the second monazite generation (see Didier et al., 2014 for details).