10 Pentti Eskola. (CXMÉ 
But the marble has never been injected with minute veins 
and lenses of granite. It seems, as though the limestone 
could not be migmatitized, a feature also very striking in 
the Archaean of Finland. ; 
At the boundaries between the limestones and the dikes 
of aplitic granites there are never any contact minerals. 
Dikes of pegmatite are sometimes coated with a contact- 
wall of diopside and amphibole and also scapolite. Where 
the limestone is, as larger masses, directly bounded by 
ordinary granites, either aplitic or porphyritic, there are no 
contact minerals whatever. But the granite often encloses 
fragments of limestone, and these have commonly been 
transformed into an dradite-skarn, a phenomenon of 
exceeding interest, as will be pointed out on later pages. 
Theintrusions within the migmatitic area of Sviatoy 
Noss are of two principal kinds: 1) those forming the younger 
injected portion in the migmatites, occurring in the 
form of thin veins or lenses, and 2) well-defined dik es. 
Most kinds of the latter also occur within the granite-grano- 
diorite area. 
Theinjected veins and lenses generally bear 
resemblance to pegmatite, being coarsely crystalline and, as 
a rule, poor in mafic minerals. 
Among the true dik es with sharp boundaries we may 
separate two groups of very different ages. The first group 
embraces all those dikes intruded simultaneously with or 
shortly after the intrusion of the granite batholith. They 
consist of phanerocrystalline rocks, showing true abyssal - 
characters. In the second group we include dikes of basalt 
and related rocks, being probably from the Tertiary period. 
The dike-rocks of this category show amygdaloid structure 
and other evidence of having consolidated at shallow depths:. 
They are, however, hypabyssal rather than volcanic, a fact 
easily intelligible, if the mode of their occurrence is considered 
along side with the development of the orography. The 
exposure of basalt observed is situated on the lake shore, 
i. e. on the floor of the wave-cut terrace and landside of the 
main displacement. In this point the amount of denudation 
