267 
locality have not been found, whilst, on the other hand, the 
nepheline-porphyries have only’ been found in the Igaliko district. 
To some degree this difference may possibly be due to the in- 
completeness of the investigations. 
The above list should only be regarded as_ preliminary. 
Many of the specimens collected are rocks which have under- 
gone slight alterations, and only very few of them have been 
chemically analyzed. Consequently, the systematic position of 
these rocks is in several cases somewhat dubious. As already 
mentioned, moreover, the dykes have not been subjected to any 
systematic study during the field work, and many small areas 
have not been visited at all, not even those which from the 
boat could be seen to be extremely rich in dykes. It is there- 
fore likely that the number of dyke-rocks will be increased con- 
siderably on future research. 
Diabase dykes. — Dykes of a diabase-like appearance fine- 
grained or dense and of a greenish-black colour are commonly 
found both in the granite and the sandstone territories. As 
pointed out by Dr. Sreensrrur' they are not as frequent as the 
red-coloured porphyry dykes mentioned below. They are nearly 
always of an altered or weathered appearance, and have not 
been subjected to closer investigation. 
Monzonite-porphyry. — A few hundred meters north of 
the houses in Igaliko the sandstone is penetrated by a por- 
phyry dyke 15—20 meters wide of a strike almost N. E.— 
5. W. Looked at from a distance, this dyke appears of a light 
gray or greenish colour, forming a sharp contrast to the sur- 
rounding dark red sandstone. As it, moreover, projects a little 
above the surface of the sandstone, it is easily perceptible even 
from the opposite side of the fjord. It was first mentioned by 
Dr. Pincer*. In hand specimens the rock is grayish-green. The 
7 Meddelelser om Grønland XXXIV, 1909, р. 126. 
? Om den af Porphyrgange gennembrudte rede Sandsten. Videnskabernes 
Selskabs Skrifter 1843, p. 16. 
