50 Sypney H. BALL: 
of 1.6 km (one mile) across the strike, (that is, approximately north and 
south) both contain graphite, in the former as flake and in the latter 
as plates up to 1.5 cm (one-half inch) in diameter. The limestone, itself, 
is also graphitic and, in places, carries a fair percentage of graphite 
plates 0.6 cm (one-quarter inch) in diameter. At one point, graphite 
aggregates 23 cm (nine inches) in diameter and, composed of 2.5 cm 
(one inch) plates, occur in the limestone. А little pyrite is associated 
with the graphite. 
Microscopie examination shows that the graphite occurs (1) as 
irregular grains having interlocking boundaries with 
calcite; (2) as tongues protruding into the calcite and 
most commonly (3) as laths. The latter occur parti- 
cularly in the calcite-pure portion of the limestone 
and may be enclosed in a single grain or may extend 
from one mineral to another (see fig. 22) in which case 
they clearly post-date the crystallization of both 
calcite and diopside. Although it appears probable 
that some of the graphite, tremolite and calcite are 
contemporaneous most of the graphite appears to be 
of later crystallization and probably replaces the 
other minerals of the limestone, particularly calcite. 
À In the northern part of the east coast of Green- 
ee land on the shores of False Bay Dr. F T т 
in crystalline lime- У Dr. Franz TouLa!) 
stone Nugsuak Pe- found crystalline dolomite bands in gneiss. The 
ninsula. limestone contains abundant lamillar graphite. 
Hate ai rare (ee) Unless bodies of practically pure graphite are 
cutting calcite (barred) $ à 2 Е i 
and diopside (stippled). found in the limestone, the graphite-bearing lime- 
ЕАО OD (rmes. stone is not of economic interest, since the percen- 
tage of graphite present is not as a rule large, and 
the separation of a clean product by milling, particularly as mica is 
present, is difficult. 
The graphite of the limestone is similar to that of the surrounding 
granite gneisses, and is usually associated with graphite-bearing peg- 
matites. Although, the graphite was presumably deposited during the 
intrusion of the pegmatite, it may, of course, be merely the recrystallized 
carbonaceous matter originally а constituent of the limestone when it 
was deposited as calcareous mud. 
7, . 
Graphiticschists,aregionallymetamorphosed carbonaceous mud. 
On Inugsuk Peninsula near Ivigtut one of the members of the 
ancient micaschist-limestone series is a fine-grained, black, slaty schist 
1) Die 2te Deutsche Nordpolfahrt Wissenschaftliche Ergebnisse, Zweite Ab- 
theilung, Zweiter Band Leipzig, 1874. 
