56 
by erosion its unusually pointed and picturesque appearance. 
The difference in outer form between Kitdlavat and Iviangusat 
can be naturally explained by the difference in the dip of the 
diabase dykes; on Iviangusat the dip as mentioned is about 
60° towards the south, but on Kitdlavat the dykes are almost 
vertical. 
MOUNT NUNASARNAUSAK. 
The amphitheatre of Kangerdluarsuk is enclosed towards 
the north-west by the 770 meters high Mount Nunasarnausak, 
which extends right out to the fjord with an almost vertical, 
precipitous wall. The photograph Pl. VII, Fig. 2, will give some 
notion of the picturesque appearance of the mountain; the 
coloured sketch, Pl. V, Fig. 1, shows the geological structure. 
Nunasarnausak may be said to represent one large orogra- 
phie block which consists of Algonkian granite and Devonian 
sandstone with sills of diabase. The whole block has apparently 
sunk some distance down into the newer abyssal rocks, and 
the beds show a dip of almost 10° towards the north-east or 
north-north-east. The uppermost part of the mountain forms 
a small plateau, whose surface slopes in the direction mentioned; 
as already described by Dr. Sreexsrrur, the plateau is ice-smoothed 
and the direction of the striation is from Е. М. Е. to W.S. W?. 
The highest point lies close out towards the Kangerdluarsuk 
Fjord and offers a magnificent view over the whole region. 
The abrupt wall of the mountain towards Kangerdluarsuk 
presents the following succession of sedimentary and igneous 
rocks in descending order (cf. Pl. V, Fig. 1). 
1. A sheet of diabase almost 150 meters thick. This 
sheet is marked on the cliff wall as a conspicuous, black band; 
it composes the uppermost plateau. The rock is of a greenish 
black or grayish black colour, fine-grained or medium-grained, 
and of a distinct ophitic structure. At some places it is 
1 Meddelelser om Grenland II (1881), p. 33. 
