8 | ; Pentti Eskola. 
Some rocks related to the amphibolites may -posatkla VS 
have been formed by the pneumatolytic action of granitic 
magma on the limestone. A fact that may be suggestive of 
such a hypothesis is the occurrence of certain exceptional 
rocks found only as blocks on the shore-beach, and composed - 
chiefly of diopsidic pyroxene and very anorthitic plagioclase 
(bytownite), besides pale green hornblende and abundant 
titanite. For such a rock I can hardly find any other expla- 
nation than the well known theory of Adams concerning the 
formation of amphibolites by the action of granites. Besides 
this vague support for Adams” theory I have no other evi- 
dences and I believe it is, as far as the rocks of Sviatoy <: 
Noss are considered, applicable only on a very limited scale. 
The amphibolites are injected with the granite like - 
the gneissoid rocks. Those varieties which are quartz- 
bearing and at the same time strongly foliated, have often 
given rise to intimately mixed arterites, whilst more massive 
amphibolites, and especially those rich in hornblende, have 
been more resistant against the injection and have only - 
been invaded by the granite in the form of cross-cutting - 
dikes, the whole being what is generally called eruptive 
breccia. 
Very typical adergneiss derived from an amphibolite or 
amphibole-gneiss, is exposed in the promontory near the 
North Cape of Sviatoy Noss. These rocks may be studied 
in the blocks on the shore-beach (fig. 4). ONE 
Going southwards from the North Cape along the Tshivir- 8 
kouy shore one meets with amphibolite-adergneiss in which 
the intrusive portion is largely made up of quartz. This - 
kind of rock which is apparently a transitional type between 
true injected migmatites and intensely metamorphosed 5 
rocks with veinlets of quartz, is exposed on the isle of Kylser 3 
hey and neighbouring shores of Sviatoy Noss. PÅ 
As a general remark on the migmatites of Sviatoy Noss, 
as compared e. g. with related rock types in Finland, we = 
may state that the former are represented by adergneisses 
and eruptive-breccias rather than by true remelted or anatec- = 
tic rocks. Such almost completely assimilated or »nebulitie» 
