I2 Pentti Eskola. (EXIT 
still superheated, resorbed its own metasomatic contact = 
products. 
The rounded fragments of andradite-skarn, so common 
in certain parts of the sviatonossite mass, are in favour of 
the latter hypothesis, as they clearly prove that assimilation 2 
has worked on the skarn, not on the limestone. Such an assi- 
milation has not been restricted to some particular cases but 
has taken place on a large scale. 
We may therefore regard the resorption of the andradite- 
skarn as an objective fact and go further to see, how this 
process may be understood and what röle it may have played 
in the genesis of the sviatonossite. S 
To understand the mechanics of the skarn-formation, SO: 
far as possible, we must again appeal to field-observation. The 
following seems to be a fact of importance: Aplitic and por- 
phyritic granite, in large masses as well as in narrow dikes, 
was repeatedly found in immediate contact with the lime- 
stone, but nowhere were any traces of andradite-skarn to 
be found at such contacts. Contact-walls of lime-silicates, 
such as diopside, amphiboles or scapolite, were only rarely 
observed. In the most common case the limestone meets 
the intrusive rock along smooth surfaces, like those of 
fissures in solid rocks, without any contact-formations. 
It is in the enclosed fragments only that skarn is met with, 
and in these indeed the metasomatosis has been such a 
regular case that I did not happen to find any inclusion of 
limestone in the intrusive rock that had not, at least in some 
degree, altered into andradite-skarn. 
The absence of contact-minerals at the actual contacts — 
must not be interpreted as a consequence of a too rapid 
cooling at the contacts. On the contrary, there are no signs 
of chilled zones in the granite masses: the structure of the 
aplitic granites remains the same up to the contact-surface. 
The older schistose rocks have been intimately and tho- 
roughly injected by the intrusives. This process must have 
continued during very long periods, and it is therefore com- 
prehensible, that the invaded rock had assumed nearly the 
same temperature as the intruding masses. This temperature 
