Plate 27. 



A. Contrast of normal sericite schist of Monk formation (left) and contact-metamorphosed 

 equivalent in aureole of summit granite stock, a coarse-grained, glittering muscovite 

 schist (right). The sericite schist specimen shows dark patches of surface stain. 

 One-half natural size. 



B. Spangled, garnetiferous schist characteristic of Belt E of Priest River Terrane. 

 Banding represents original belding of a silicious argillite. Three-fourths 

 natural size. 



25a— vol. ii— p. 2GG. 



