CONTENTS. 7 
Pagn 
Chapter VI. Summary of conclusions 82 
Evidence of the eruptive character of the two rock types 82 
Field evidence 82 
Schistosity 82 
Lamination 82 
The slates s 82 
Absence of gradation between igneous and clastic rocks 83 
Surface-flow features 83 
Petrographical evidence ^ 83 
Structural ■. 83 
Mineralogical -. 84 
Chemical 84 
Original rock types 84 
Acid igneor" - ocks 84 
Basic igneous rocks „ ■. 85 
Similar rocks in other regions 8(5 
Literature 87 
