82 
kind to that mentioned above (p. 78), though of less intensity. 
The whole lower portion of the arfvedsonite-granite body which 
is exposed at a height of 300--500 meters in the mountain 
slope to the west of North Siorarsuit, is so distinctly red that 
the colour is conspicuous at a distance of several kilometers; 
we also find red patches of large extent in the northern part 
of the arfvedsonite-granite area. 
IGDLUNGUAK AND TUGTUP AGTAKORFIA. 
West of the alluvial fan of North Siorarsuit the side of 
the mountain descends more or less abruptly towards the fjord, 
and in front there is only a narrow, rocky beach. This part 
of the coast has only been investigated cursorily in geological 
regards but does not seem to offer features in any essential 
way different from those on the opposite side of the fjord. 
Some few words only will be devoted to the two mineral loca- 
lities, Igdlunguak and Tugtup Agtakôrfia know from Dr. Емхк’$ 
Expedition of 18971. 
Igdlunguak lies on the north side of Tunugdliarfik right 
opposite Naujakasik (see Map Pl. Ш) and but a short distance 
west of North Siorarsuit. At this place the coast-line forms 
two small projecting points, which are built up of arfvedsonite- 
lujavrite and naujaite. On the point to the east the lujavrite 
exhibits a peculiar kind of orbicular structure, containing nu- 
merous spheroids of 2—20 centimeters in diameter, which are 
frequently somewhat flattened parallel to the schistosity of the 
rock. The spheroids have essentially the same composition as 
the surrounding rock, but they are somewhat more liable to 
1 The localities were first described by G. Frink in Meddelelser om Gron- 
land XIV (1898), pp. 256 and 258 under the names Agdlunguak and 
Tutop Agdlerkofia. The minerals from these places were described by 
J. С. MogerG in Meddelelser om Grønland XX (1898), р. 245, and 0. В. 
Воссию and Cur. WINTHER in Meddelelser om Grønland XXIV (1899), 
р. 191. 
