58 
3. The granite, which supports the sandstone in the 
south-western part of Nunasarnausak, is a white or reddish 
biotite-granite with large (up to 2 centimeters), porphyritic cry- 
stals of felspar; it is not different from the ordinary Algonkian, 
Julianehaab granite. On Pl. V (Fig. 1) only the eastern point 
of the granite is seen, but further to the south-west the granite 
comes down to the beach; it composes the Niakornarsuk Penin- 
sula and the whole region further west. A little north-west of 
Niakornarsuk a 20 meters dyke of a somewhat porphyritic diabase 
intersects the granite; the direction of the dyke corresponds 
with the main direction of the fjord. 
4. Under the granite in the south-western part of Nuna- 
sarnausak and directly underlying the sandstone in the eastern 
portion of the mountain, the augite-syenite appears in a belt of 
very variable breadth. This is obviously a continuation of the 
augite-syenite belt on the south side of the fjord, as the rock 
is of quite the same character as there; for which reason 
reference may be made to the previous description (p. 50). 
The augite-syenite forms the coast cliffs on a portion of 
the distance between Niakornarsuk and Kekertausak. At several 
places it contains veins of pegmatite which consist mainly of 
felspar and amphibole in crystals 5—8 centimeters long; albite, 
green garnet and ilvaite’ are found as secondary products in 
this pegmatite. The ilvaite occupies the place of dissolved 
amphibole crystals. Some of the pegmatite veins are hori- 
zontal and 0:1—0'3 meters in thickness, others have an irre- 
gular course and greatly varying breadth. The ilvaite is also 
found in the augite-syenite itself as an alteration product. 
The contact-plane between the augite-syenite and the Al- 
gonkian granite intersects the coast-line a little distance east 
of Niakornarsuk. Here the augite-syenite shows а 4—8 meters 
1 The ilvaite from this locality has been described by J. LORENZEN, (Med- 
delelser om Grønland IJ, 1881, р. 67. — Zeitschrift für Krystallographie 
IX, 1884, p. 243. — Mineralog. Magazine V, p. 63). 
