Academy of Sciences] 

 No. 1] 



NORTHERN EUROPE. 



17 



with normal marine sediments, tuffs, limestones, and chert. A noteworthy feature of these 

 lavas is the presence of phenocrysts of albite, oligoclase and andesine, the later Upper Middle 



GRANITES-* 

 EXTEND-* 



Crysfalline Schisrs 



[LTD 

 Gabbros 



wm 



Schistose 

 Amphibolic 



Danite 



Dunite Serpentine 



Fig. 5.— Geological map of the Tagil District, Ural Mountains. (After Wyssotsky.) 



and Upper Devonian volcanic rocks being more gabbroid in composition. These eruptions 

 were succeeded before the close of Devonian times, by the first severe dislocation with the 

 formation of a series of anticlinal and synclinal folds, later broken by a series of transverse 



