43 
Nearest the fjord they have a dip of 20°—30° towards N. W. 
and N.N. W.; further in on the plateau they are almost hori- 
zontal and may even at places show a slight inclination in the 
opposite direction; still further in, the dip again becomes north- 
westerly, but soon afterwards the stratification gradually dis- 
appears and close to the south-east border the rock is uniform 
and without banded structure. 
The kakortokite. — Petrographically the variegated sheets 
of Kringlerne are nearly related, so that they may be regarded 
as varieties of one rock-type, for which the name kakortokite 
has been chosen!. 
The kakortokite is a coarse-grained, distinctly miarolitic 
rock and recalls in its outer appearance nepheline-syenites of 
the type which Brüccer has designated by the name foyaite?, 
that is to say, the most prominent, structural fealure is the 
plate-like form of the felspar crystals, which show a strong 
tendency to parallel arrangement. But the kakortokite is distinct 
from the ordinary foyaites by containing a very high percentage 
of dark-coloured minerals; in this respect it resembles the 
lujavrites or even exceeds them. Characteristic of the kakortokite 
is further the abundance of well-developed, moderately small 
crystals of eudialyte and the frequent occurrence of a bedded 
or sheeted structure. 
The “white” kakortokite which forms the thick, white sheets 
is one of the most beautiful rock-types to be found anywhere. 
The felspar plates are white, and not semitransparent as in the 
naujaite and lujavrite; their thickness is 05—15 millimeters 
(in the varieties with coarsest grain 1’0—1'77 millimeters), their 
length and breadth are about ten times the thickness. They are 
intermingled with grayish clear grains of nepheline, black prisms 
or anhedra of ægirine and arfvedsonite, and bright red crystals of 
1 From Kakortok, the Greenland name for the colony Julianehaab. 
? Zeitschrift für Krystallographie XVI, 1890, р. 39. 
