42 Washington — Study of the Glaucophane Schists. 



Si0 2 47-36 



A1 2 G 3 .-_ 19-74 



Fe 2 3 .- 3-10 



FeO 5-71 



MgO 8-24 



CaO _.. 4-63 



Na o 3-57 



K 2 U _. 0-51 



H 2 110°+ 5-89 



H 2 110°— 0-16 



CO a - . trace 



TiO, ---- 1-36 



MnO trace 



100-27 

 Epidote-glaucophane schist. Srnjevacki Potok, Fruska Gora, 

 Croatia. Washington anal. 



Anglesey, Wales. 



The occurrence of glancophane schists on Anglesey was 

 first observed by Blake* in 1888. The area is small and the 

 composition apparently quite uniform, only epidote-glauco- 

 phane schist being mentioned. This occurs as local modifica- 

 tions of a hornblende schist which is probably derived from a 

 diorite, which occurs in the vicinity. f 



Through the kindness of Mr. Teall and Mr. E. B. Greenly 

 I received specimens from the most typical locality, " The 

 Monument," near Menai Bridge, on Anglesey, one of which 

 was analyzed. 



The specimens are very uniform, and are dense, compact, 

 fibrous rather than foliated, schists, of a dark, blue-black color, 



Si0 2 47-47 



A1 2 G 3 15-25 



Fe 2 3 ._ 8-22 



FeO -. 7-19 



MgO 5-96 



CaO ... 11*32 



Na 2 2-11 



K 2 0-56 



H s O 110° + 2-13 



H 2 110°- 0*04 



TiO s _. notdet. 



MnO trace 



100-25 

 Epidote-glaucophane schist. The Monument, Anglesey, Wales. 

 Washington, anal. 



* Blake, Geol. Map., Decade ITI, vol. v, p. 125, 1888. 



f Blake, Rep. Brit. Assoc. Adv. ScL, 1888, p. 406. Also op. cit., p. 125. 

 Harker, Petrol, for Stud. 1897, p. 314. 



