one of them, occurring about 50 meters above Igaliko, is in 
its upper part of a pronounced slaggy appearance. But pebbles 
of diabase have not been found anywhere in the sandstone beds 
which immediately cover the diabase sheets, and Dr. Steenstrup 
consequently regards it as being most probable that all the 
diabase sheets are intrusive. On the other hand. the slaggy 
surfaces show that the rock cannot have been formed to any very 
considerable depth below the surface, and thus we come to the 
conclusion that Igaliko’s slaggy diabase represents one of the 
oldest, if not the oldest, manifestation of the igneous activity 
which in its further development produced the batholites of 
Igaliko and [limausak. 
The sandstone appears again north of the Itivdlersuak de- 
pression, and forms the lIliortafik Plateau which has only an 
altitude of 2—300 meters. Here the stratification is horizontal 
and the thickness of the sandstone stratum is very slight, so 
that the underlying granite is visible at the foot of the plateau 
on the north western as well as on the southern side (vide 
Fig. 22, р. 253). The sandstone on the Шомайк Plateau is 
peculiar from the fact that the upper beds are white and 
quartzitic, whilst the sandstone strata are red some distance 
below the surface on the south western part of the plateau. 
It is likely that the quartzitic character of the upper beds 
is due to contact metamorphism, as the beds, which are now 
on the surface of the plateau, were at one time covered 
either by augite-syenite or some intrusive sheet of a consider- 
able thickness. 
The sandstone area which is to be seen on tbe map (Pl. IV) 
west of the Tunugdliarfik Fjord is the largest of all of them, 
and stretches westward towards the Himausak batholite. The 
sandstone in this area closely corresponds to that near Igaliko. 
