64 
the original nature of the rock is more or less disguised. In 
the first stages of the alteration there is a copious formation 
of yellowish green epidote, a mineral which is otherwise quite 
absent from these rocks. Where the pneumatolytic metamor- 
phism is further advanced, the rock contains a considerable 
amount of other secondary minerals: micaceous hematite, small 
green garnet crystals, fluorite, albite in well-formed crystals, 
and as the most characteristic product splendid crystals of 
ilvaite showing a rich diversity of crystal forms!. The different 
stages of the metamorphism are most readily seen in the nau- 
jaite owing to the peculiar structure of this rock. In the par- 
tially altered naujaite the sodalite and the nepheline are replaced 
by a mixture of epidote and a white, spreustein-like aggregate 
which consists in part of secondary felspar; some pseudomorphs 
consist almost entirely of spreustein, others mainly of epidote. 
The dark-coloured minerals in the naujaite are already at this 
stage entirely converted into a dark-green, flaky chlorite; the 
felspar on the other hand is unchanged except that it has as- 
sumed a slightly reddish colour. With further alteration the 
felspar is also attacked and becomes dull and spreustein-like, 
ilvaite develops in place of the chlorite and small scales of 
hematite appear here and there. 
ENVIRONS OF NAUJAKASIK AND TUPERSUATSIAK. 
The coast-cliffs. — At Naujakasik (‘the bad gull-cliff”) а 
small rocky platform is found at the beach, which permits of 
easy landing. At Tupersuatsiak (‘‘place suitable to set up tents”) 
there is a small bay and within this a small green plot (Pl. ХЦ. 
Between the two places the coast-line is formed by a continu- 
ous, vertical cliff-wall of 100—200 meters in height, and above 
1 0.B. BOGGILD, On ilvaite from Siorarsuit. Meddelelser om Grønland XXV, 
р. 43 (1902). — У. GOLDSCHMIDT, Ueber Albit von Grönland. Meddelelser 
om Gronland XXXIV (1907). 
