Fig. 15

Diagenesis and metamorphic grade versus vitrinite reflectance of Bündnerschiefer and Flysch in a trace from Vilanspitze to the Plessur river near Chur (Figs. 2, 4). Data from Petrova et al., (2002, black symbols) homologised according to illite crystallinity standards (CIS) from different laboratories by Ferreiro Mählmann and Frey (2012, red symbols). Formations: R, Ruchberg; G, Gyrenspitz; PF, Pfävigrat; S, Sassauna; V, Valzeina. Note that the authors Ferreiro Mählmann and Frey (2012) suggest that the combined use of laboratory standards provides a more accurate picture of the transition from diagenesis to anchizonal metamorphism