93 
from this in containing numerous phenocrysts of well-developed, 
bipyramidal form. 
Other dyke-rocks are more restricted in their occurrence. 
Thus the uppermost part of Mount Steenstrup contains a number 
of dykes which consist of a red, coarse-grained granite and 
are probably connected with the underlying arfvedsonite-granite ; 
they have an irregular course and are from one to ten meters 
in width. They cut through the above-mentioned dykes and 
sills of syenite-porphyry and contain fragments of these. One 
of the arfvedsonite-granite dykes passes through the very top of 
Mount Steenstrup. — A dyke of grorudite, one meter wide, of 
a very fine-grained structure and light grayish-green colour, 
occurs east of Kakarsuak ata height of about 600 meters. A dyke 
of a similar grayish-green rock, but containing no quartz, cuts 
the porphyrite of the mountain south-west of Tasek (about 750 
meters above the sea). This dyke is only half a meter in width 
and is remarkable for its fine spherulitic structure, with densely 
packed spherulites, which are from 4 to 8 millimeters in dia- 
meter and consist of radiating fibres of felspar and egirine. 
It may be mentioned, lastly, that a vein containing a little 
copper-glance, bornite, malachite, brown garnet and albite, has 
been observed in the porphyrite above Tunuarmiut at a height 
of about 800 meters!. 
NARSAK DISTRICT. 
The Narsak District referred to here embraces the outer- 
most (south-western) part of the peninsula between Sermilik and 
Tunugdliarfik Fjords, including Mount Kakarsuak and the coastal 
stretch lying to the south and west of this. 
7 0. В. BOGGILD, Mineralogia Groenlandica р. 56 (Meddelelser om Gren- 
land ХХХИ, 1905). 
