69 
sheet in its uppermost portion assumes a divergent character, 
and is covered by other coarse-grained rocks. Conditions of 
this kind are seen on the plateau north-east of Nunasarnausak 
and at a place which lies a little over 200 meters above the 
sea, south-west of Tupersuatsiak 
At the former place the sodalite-foyaite is overlain by a 
foyaite poor in sodalite, and the foyaite in turn is covered by 
pulaskite. Between these rocks no sharp boundaries can be 
drawn, but they are connected with one another by insensible 
gradations, The foyaite differs from the sodalite-foyaite in the 
following characters. The sodalite is much scarcer or quite 
wanting, the felspar plates are relatively thinner, and the struc- 
ture is thus more distinctly ‘‘trachytoid” (as a rule, however, 
there is no parallel arrangement of the felspar plates). Further, 
the nepheline has a greenish or reddish eleolitic appearance, 
eudyalite is almost entirely absent, and sometimes the rock con- 
tains olivine. The microscope also shows differences in the 
character of the dark minerals, as will be discussed in more 
detail in the petrographic section. This foyaite sheet seems to 
have but little thickness. 
The pulaskite, which covers the foyaite, forms a more 
considerable sheet, about 20—50 meters thick. This rock is 
white, coarse-grained, somewhat miarolitic, and consists mainly 
of white felspar in thick, plate-like crystals giving stout rectan- 
gular sections; between these are anhedra of dark-coloured 
minerals and iron-ore, sporadically also white, dull pseudo- 
morphs which probably represent nepheline. Apart from the 
form of the felspar crystals the pulaskite has a good deal of 
outer resemblance to the earlier-mentioned augite-syenite; like 
the latter it crumbles easily and a rusty coating often covers 
the joint-planes. 
In the locality south-west of Tupersuatsiak the sodalite: 
foyaite is covered by a 20—30 meters thick sheet of pulaskite. 
This can be followed southwards for a considerable distance, 
