Clakke and Williams.— of Darling Jlange. 
173 
A 
B 
C 
D 
E 
Y 
SiO 
50.67 
49.28 
49.04 
50.96 
49.53 
49.22 
Al.,0, . . 
14.01 
13.62 
16.55 
11.89 
12.92 
12.(>2 
Pe..O, . . 
1.38 
3.13 
2.52 
2.54 
2.60 
3.16 
IhiO . . - 
5.20 
11.92 
9.84 
13.64 
11.40 
11.09 
MnO . . 
not determined 
..34 
.35 
.3>3 
MgO . . 
8.12 
8.29 
7.43 
6.26 
6.24 
6.42 
CaO . . 
13.16 
7.35 
9.70 
9.94 
10.37 
10.59 
Na.,0 . . 
2.04 
2.68 
2.54 
2.68 
2.08 
1.86 
Tv.,0 . . 
2.32 
.29 
.28 
.29 
.36 
.30 
H.,0— . . 
,23 
.18 
.18 
.16 
.09 
.12 
T1..0+ . . 
.70 
.70 
.61 
.05 
2,21 
2.24 
TiO.. . . . 
1.84 
2.13 
2.00 
BaO . . . 
nil 
nil 
ZrO.. . . . 
nil 
nil 
CO 
nil 
nil 
nil 
P.,0, . . . 
.12 
.28 
.25 
nil 
.16 
.09 
PeS., . . 
trace 
.28 
22 
Cr..0„ VM., 
Cu.B 
trace 
trace 
Total 
.97.95 
97.72 
98.94 
100.59 
100.72 
100.26 
A— Darlin 
gton 
Area, 
40 chains 
south of 
mouth 
of Smith 
’s Mil! 
Brook. 
B tfc C — Boyii Quarries. 
I)_Sniitirs Mill, 2 uiiles east of Darlington. Dr. Simpson notes 
that the roek is eomposed nlmost entirely of hibradonte ami 
hornhleiide. 
& Y — Quarry at Bickley Brook Beservoir, near Roleystone Area. 
E is from tlie tine orained edge. S from the coarse central 
])art of the dyke. Dr. Sinpison finds that the minerals in 
order of abundance are: Hornblende, plagioclase, ilmenite, 
magnetite, (iiiartz, leiicoxene, aimtite, e]iidote. 
2. Tidaiion to othrr roWr.s'.— The basic dykes cut the acid and 
nitra-acid intrusions, and must have been injected at some period 
subsequent to the consolidation of the granite and its associated 
acid intrusions. The sliear zones and related later ipiartz reefs 
are clearly seen to cut e])idiorite dykt's in several places. There 
are, however, three places (right bank of Helena 2(1 chains below 
mouth of Piesse Brook, ridge on left bank .1(1 chains below mouth 
of Piesse Bnmk, small <-re.‘k which flows jiast east sid.‘ of Boyn 
Quarries) in which dykes wer<\ with hesitation, mapiied as passing 
unaffected through the shear zones. In each case the ground was 
(discured, 
