37 
north-west; the lowermost sheets of the rock are thus found 
in the neighbourhood of the Lille Elv. Further to the east, 
the underlying lujavrite appears on the surface, but the junc- 
tion of these two rocks is of quite a peculiar kind. 
On the west side of the Lille Elv already, conspicuous black 
masses begin to show in the lowest parts of the white naujaite; 
these black masses form veins which run parallel in the main 
with the naujaite beds, but they also cut across these. The 
further we go towards the east, the more numerous and broader 
become the black veins, the naujaite is divided into large and 
small fragments and lenses, and the black rock envelops these 
completely, forming a continuous, greatly branched network of 
veins, as shown schematically in Fig. 4 (p. 38). The black veins 
are composed of lujavrite; their breadth is from 0-5 to 10 meters 
or even considerably more. The lenses of the naujaite may be 
100 or 200 meters long and 10 or 20 meters in thickness, but 
some are quite small. The whole rock-complex between the 
Lille Elv and the western arm of the Laxe Elv has this charac- 
teristic structure: lenses of naujaite separated by reticular veins 
of lujavrite between them. In addition to the regularly rounded 
lenses, we now and then also find naujaite masses which have 
the form of sharp-edged fragments, and the structure then 
approaches the ordinary structure of an igneous breccia. In the 
cliffs about Tunugdliarfik the last form is the rule; the photo- 
graph PI. XIII, Fig. 2, gives a good illustration of this condition. 
In the parts round the outlet of the Lille Elv the 
lujavrites are black; here and there, however, we also find 
lujavrite of a pronounced green colour in veins 1—6 meters 
broad, which are usually flanked by black lujavrite on both 
sides. 
Following up the Lille Elv from its mouth, the lujavrite 
veins become more rare and at a height of 2—300 meters above 
the sea the cliffs consist of a uniform naujaite. At still greater 
heights (further to the west) the naujaite is covered by sodalite- 
