92 NE Pentti" Bskola ; FER 
clase (Abg,), biotite, quartz, dark green hornblende, magne- = 
tite, titanite and apatite. The large phenocrysts of cross- = 
hatched microcline contain narrow perthitic albite-laths in 4 
small amounts. Grains of plagioclase surrounding the micro- 
cline or included in it have developed abundant myrmekite, ä 
which is often restricted to the albitic border zones of the 
plagioclase, the late ORO of the implication being thus: 2 
apparent. ÅR 
The small quantities of an EA present in most of the 
porphyritic granites, in the large batholith as well as in the 
small intrusions within the migmatite area, is very striking. 
The composition must in many cases be that of a quartz- = = 
syenite. As the rocks are, at the same time, poor in mafic SE 
constituents, the alkali content must be high. Such a sub- = - 
alkaline character is really a feature common to the Trans- i 
baikalian igneous areas on the whole, so far as appears from Er. 
the investigation T the Radium Fapenieen RA bä 
The Aplitic Zone round the Tshivirkouy Batholith. 
As mentioned above the vast massif of mainly porphyritie Er 
granite and granodiorite is, towards the West, bordered by 
light-coloured medium- and even-grained granites of rather = - 
aplitic character. "Near Makarova, on the southeastern half 
of the peninsula, this granite separates the porphyritic 
variety from the migmatite area. The field-observations are, 
briefly summarized, as follows. e 
On the southeastern coast of Sviatoy Noss northeast of AN 
Makarova most part of the shore-drift consists of light grey 
even-grained granite, poor in biotite. The whole southern 
slope of the mountain ridge is made up of this granite, often 
cut by' primary dikes of still lighter aplite. The main rock is 
homogeneous and could very well be used for technical purpo- = 
ses. An ill developed jointing in the direction of the general 
strike of the schistose formations in the Northwest, being = 
about N 55” E, vertical, is always visible. Blocks of amphi- = 
bolite are sparingly enclosed in the granite and towards the : S 
migmatite area they grow gradually more and more numerous. 
