101 
Dykes cutting the nordmarkite. — The commonest dykes 
are composed of a red or reddish-brown arfvedsonite-granite ; 
they have a south-westerly direction and a width of 3— 10 meters. 
In appearance and character they are very similar to the large 
masses of arfvedsonite-granite north and east of Narsak ; prob- 
ably they are offshoots from the latter and thus indicate, that 
the consolidation of the granite has occurred later than that 
of the nordmarkite. Similar granite-dykes are observed in con- 
siderable numbers at Nungmiut, about seven kilometers N. N. W. 
of Narsak. Above Narsak a reddish-gray, bostonite-like dyke 
is found; it is ten meters wide and the direction is W. $. W. 
—E.N.E. At Narsak and at the south coast of Panernak Bay 
a few narrow (0°1—0'25 meters) and irregular dykes occur of 
the same black spherulitic rock-type, which forms dykes in the 
essexite (p. 98). A dyke of diabase is observed in the nord- 
markite at Nungmiut; this is remarkable for the vasicular 
structure of its border-zones. It is two meters wide and the 
direction is W.S. W.—E. N.E. 
The rocks of Kakarsuak. — The top of Kakarsuak consists 
of essexite-porphyrite, which directly covers the nordmarkite. 
The ‘‘Kakarsuak porphyrite”, as the rock was called during the 
fieldwork, is greatly altered by contact-metamorphism and is 
remarkable for its large and numerous felspar phenocrysts, which 
are packed so thickly together that the dark ground-mass is 
reduced to a very small amount filling the interspaces between 
them. These phenocrysts show twin-lamellation and usually 
have a form which gives broad rectangular sections; in size 
they are very varying (1—10 centimeters) and they are of a dull 
greenish white appearance. The essexite-perphyrite is a minor 
intrusion of irregular shape, which has been intruded among 
the bedded porphyries. It has a great resemblance to the 
above-mentioned border-facies of the essexite. 
The essexite-porphyrite is cut by numerous dykes of red 
arfvedsonite-granite ; the width of these dykes is from 0'I meter 
