Å 220 3 
VTI 
12 : Pentti Eskola. (LIITE 
Aplites and lamprophyric rocks often form composite dike 
YYTRE 
breccias. 
Within the migmatite area there are also larger masses 
of granites, porphyritic as well as aplitice. Some of these 
s 
intrusive masses, though evidently connected genetically 
AV 
126; 
with the granites and granodiorites, have quite another 
composition. Part of them may be classed with syenites, : 
while others have a peculiar and uncommon composition, 
chemically characterized by the abundance of lime and - 
alkalies and mineralogically by the presence of the lime- 
ferri-garnet, andradite, the other constituents being those 
of a syenite. This rock will here be called sviatonossite. . 
The sviatonossite deserves exceeding interest from the 
petrological point of view, as it seems to exhibit a positive 
illustration of Daly's well-known theory concerning the for- 
mation of alkaline rocks by the action of magma on lime- 
stone. This rock-series will therefore be described in a detail 
that would be unnecessary in the case of more ordinary rocks. : 
All the rock groups occurring on the peninsula of Sviatoy 
Noss, mentioned in the order of their relative age, are the > 
following. The younger schistose formations (the metamor- 
phic suite) not occurring on Sviatoy Noss, but in other parts 
of the Baikalian Region are mentioned within parentheses. 
Basalt ( Tertiary). 
( Crystalline schists of the metamorphic suite, Palaeozoic?). 
The Tshivirkouy batholith and other abyssal intrusives 
connected with the latter: Aplite, pegmatite, lam 
prophyric dike-rocks, granite, granodio- 
rite, andradite-syenite or sviatonossitenmn 
diorite, gabbro, hornblendite. 
Older intrusives in the crystalline schists: diorite and 
gabbro. 
Crystalline schists of the crystalline suite: Volcanogeneous 
(in part possibly plutonogeneous) rocks: amphibolites 
and augengneisses. Sedimentogenous rocks: Crystal 
line limestone, amphibolite, amphibole- 
gneiss and other gneisses, quartzite-gneisses. 
