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extinction angle on (010) is 7° indicating the presence of 
albite silicate to a slight extent. A few ægirine-prisms also 
occur as phenocrysts. The ground mass consists of felspar, 
egirine, analcime, and probably nepheline, besides small quan- 
tities of a reddish-brown strongly pleochroic biotite, a few 
small patches of a blue arfvedsonite-like mineral, and perhaps 
sodalite. The felspar of the ground mass occurs in laths about 
half a millimeter in length; they are twinned, and seem to be 
albite, but an exact determination was not possible on account 
of their richness in egirine-microlites and other inclusions. 
The egirine is very abundant, and shaped both like prisms 
and allotriomorphic anhedra. The analcime is also very 
abundant and is apparently quite secondary. It contains rem- 
nants of a stronger refractive mineral resembling nepheline. 
CONTACT RELATIONS OF THE IGALIKO BATHOLITE. 
As may be seen from the geological map (Pl. IV) the 
boundaries of the Igaliko batholite are partially covered by al- 
luvial deposits and by the sea, and partially they have not been 
explored. Only in the district between the Tunugdliarfik Fjord 
and the large valley north of Tavdlorutit in a tract of about 
seven kilometers the author had the opportunity to study 
the junction between the augite-syenite and the rocks of an 
older origin, which are represented here by red sandstone and 
granite. 
The junctions are of a type far different from those met 
with near the Ilimausak batholite. The contact planes observed 
at the latter are in some places vertical, whilst in others the 
rocks of an older origin overlie the batholite; but at the part 
of the junction which has been examined the contact plane is 
nclined towards the augite-syenite, so that we may regard this 
as resting upon the said rocks at its junction, just as it, in its 
turn, has been covered by nepheline-syenite. 
