133 
distriet it is also of interest to note that one of the analyses 
of lardalite, given by Bröccer and quoted in С in the table, 
is pretty similar to the analysis of the foyaite of Naujakasik; 
it differs, however, in containing a somewhat greater amount 
of lime. 
SODALITE-FOYAITE. 
Occurrence. — The sodalite-foyaite occurs as a heavy 
sheet underlying the foyaite described above and resting on 
the naujaite. It occupies two areas separated by the Tunug- 
dliarfik Fjord. The area north of the fjord may be estimated 
at about 20 km? and that south of the fjord at about 8 km?. 
In the former area the sodalite-foyaite is covered by the 
arfvedsonite-granite and the transition rocks mentioned in the 
preceding pages, and it is only visible in a narrow zone of 
approximately circular form. South of the fjord this rock is 
for the most part uncovered. Both areas have evidently been 
considerably reduced by the effects of erosion, and there is no 
doubt that the sodalite-foyaite originally formed one continuous 
sheet extending from the high mountains of Ilimausak to Kan- 
gerdluarsuk and covering an area of about 50 km?. The thick- 
ness of the sheet varies from 2 to more than 150 meters; yet 
“the mean thickness cannot be estimated at less than about 
100 meters. Thus the total volume of sodalite-foyaite originally 
present within the Ilimausak complex probably amounts to about 
5 km’. 
Macroscopic appearance. — When seen at some distance 
this rock is a medium gray owing to the freshness of the felspathic 
constituents and the considerable amount of dark minerals. In 
hand specimens the appearance is mottled in consequence of 
the very large size of grain. The structural habit on the whole 
is conditioned by the tabular felspar crystals arranged without 
any law or tendency to parallelism. Their thickness averages 
two or three millimeters, the breadth and the length are from 
