The Mineral Resources of Greenland. 49 
of the graphite at least was, therefore, formed late in the history of 
the rock. 
It is believed that these disseminated flakes of graphite in granite 
gneiss were deposited by waters of pegmatitic origin, since the veins 
and masses of graphite described in the last section are bordered by 
similar graphite-bearing granite gneiss. 
Graphite disseminated in limestone. 
In many of the limestone bands which occur on the west coast 
from Isortuarsuk fiord, north a distance of 48 km (thirty miles) graphite 
ne Bf Ha: 
AHHHN 
) Hi alas 
' 
Fig. 21. Graphite in limestone, Nugsuak, Isortok fiord. 
J, IV and VI, granite gneiss containing а few flakes of graphite up to "/4” long. 
II and XVI hornblende gneiss a sheared basic igneous rock. III, V, XI, XIII 
and XV quartz-felspar-biotite pegmatite containing plates of graphite. VII Soil 
and boulders. VIII Crystalline limestone containing flakes of graphite up to 1/4” 
long; chondrodite, spinel, phlogopite, diopside, pyrite etc. IX Dense diopside- 
calcite-quartz rock, containing a little phlogopite and graphite, a form of meta- 
morphic limestone. X, XII, XIV, garnetiferous granite gneiss carrying flake 
graphite. XVII granite. XVIII granite gneiss. 
occurs as flakes from 0.3—0.6 cm (one-eighth to one-quarter inch) in 
diameter. Pegmatites which may contain graphite are usually associated 
with such deposits. These limestone bands vary in width from 0.6 to 
300 m (2 to 1 000 feet) and are banded parallel to the gneissic planes 
of the enclosing granite gneiss. Small areas consist of practically pure 
interlocking grains of calcite, but, as a rule, numerous other mineral 
including diopside, chondrodite, phlogopite, graphite, tremolite, scapolite, 
spinel and pyrite are also present. Likewise, near pegmatite bodies 
vugs in limestone may contain graphite leaves 2 cm in diameter radiating 
from a common centre, 8 km (5 miles) М.Е. of Ekalugsuit for example. 
Nugsuak (Fig. 21), a promontory on the north side of Isortok fiord 
some 19 km (twelve miles) from its mouth, consists of granite gneiss 
and some hornblende gneiss, in which are 4 or 5 bands of crystalline 
limestone parallel to the gneissic structure. The granite gneiss, usually 
garnetiferous, and quartz-felspar-biotite-garnet pegmatite, for a distance 
LXIII. i 4 
