Fig. 9

Microphotographs of key structures. Abbreviations for mineral according to Whitney and Evans (2010). a Superimposed foliations S2 and S3 in the calcschists/black schists of Battuira, Val Grana unit (sample AC01; same outcrop as Fig. 8a). b Pressure solution foliation (S3) bounding microlithons with crenulated previous S2 foliation in Liassic calcschists at Ponte Marmora, Val Grana unit (sample 38-M2111). c White mica (wm)-epidote-albite pseudomorph after lawsonite (?) in Middle Triassic carbonaceous schists (sample 35-M2108, Val Maira subunit). d Chloritoid-phengite association in quartz-mica-schist from the Cima Lubin tectonic mélange in the core of Pradleves anticline (sample AC09M). e Pseudomorph after lawsonite (?) including traces of a previous foliation (S2 ?), now transposed into S3 (sample 40-M2113, Queyras Schistes lustrés above Ussolo; cf. Fig. 8b). f Metachert with blue amphibole (glaucophane) overgrown by green amphibole (actinolite), Mte Plum klippe (sample GR20-89; cf. Fig. 8g). g Metabasite from the same klippe as (f), sample GR20-87. h: Jadeite-bearing mylonitic orthogneiss from the Acceglio-Longet band west of Pelvo d’Elva (sample 41 = 73Bel13; location Fig. 10); see Additional file 2, Figs. S1, S2 for a macroscopic view of the S/C’ mylonitic structure and more petrological details