44 SYDNEY H. BALL: 
Sigsarisok, Southern Greenland, granite gneiss contains lenticular or 
vein-like bodies of amorphous graphite. Such bodies usually occur in 
the vicinity of graphite-bearing garnetiferous pegmatite, and the near- 
lying gneisses are usually particularly schistose. The surrounding rocks 
contain disseminated flake graphite, and contemporaneously deposited 
pyrite. The walls between the graphite and the gneiss in places are 
sharply defined and elsewhere the two grade into one another. The 
gneisses, likewise, contain an unusual amount of garnet and often 
sillimanite, the latter a mineral believed to be confined to the vicinity 
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Fig. 18. Tabular bodies of graphite. Sketch map of Utokrat graphite deposit. 
of graphite bodies. The graphite in places encloses biotite and quartz. 
On account of the pyrite present, the graphite-bearing granite gneiss 
bands weather as rounded, rusty brown or yellow limonite-stained zones, 
barren of even the sparse, arctic vegetation. From the sandy slopes 
protrude a few jagged boulders. Because of their softness the pure 
graphite bodies usually occur as depressions in such zones dug out by 
the glaciers. 
The graphite is, for the most part, amorphous and usually siliceous, 
however, crystalline graphite occurs in what appear to be planes of 
movement in the amorphous graphite. 
Utokrat (See Fig. 18) which lies on the north side of Amerdlok 
fiord, fifteen miles east of Holstenborg will be described as an example. 
The country rocks are interbanded granite gneiss and hornblende gneiss 
cut by pegmatite. Both gneisses contain much garnet which, in places, 
makes up fifty percent of the rock. The pegmatite is a biotite-garnet 
quartz-felspar pegmatite in which graphite may or may not be present. 
