Table 10. Mineralogical textures of Guyet
Formation conglomerate.

Rock QTZ FFLD CHR CHPPLT SLT VLC OTH

1 4CZ 0 ee aes 0

2 SCY O2DY => 1Dz- 4+ = 8 e-2CY ~ 0CY

5 3CY 1CZ

6 30Z oGF 2

7 4CY 1DZ 1 5 er:

8 6CZ 5 (M)
9 2CZ 1CZ 0

10 3DZ 2DZ 2

| 11 3 2 |

1st ~ 202 1 12503520

26-3D 2CZ ODZ 2 0DZ

| 46-16 3DZ AGL 2

46-28 4CZ 3DZ 3CZ (CRB)
113-1 3CY iG 2

113-1A 4CY 3CZ 4CY 3 3

| 113-2 302 ds a ae 2CZ (QM)
12-7 s-30Y 30S 262-F— 22) 2DZ

126-26 4DY 4CY 30Z 3 4 302 3CY (QM)

Key
Mineral and rock abbreviations are the same as in Table 9.

MGD = modal grain diameter Missing values of MGR and
MGR = modal grain roundness MGS are due to deforma-
MGS = modal grain sphericity tional changes of the grain
Shape parameters.
Grain diameter (MM): Grain roundness: Grain sphericity:
0=4-2 A = wellrounded X = high
1=2-1 B = rounded Y = moderate
et ed C = subrounded Z = low
13 = 0.5 — 0.25 D = subangular
| 4 = 0.25 — 0.125 E = angular
5 = 0.125 — 0.063 F = very angular
6 = <0.063

| The results represent the textural characteristics of the first ten
| grains of each grain type encountered during point counting. Data
are presented only if at least five grains of the grain type con-
cerned had been counted upon completion of the point count.

| Note: Samples 1 to 11 have been analyzed for strain and are dis-

cussed further in Appendix B.

rence has similar conglomerate but also has variations
with higher chert content and a different chert type. The
chert is pure and more varied in colour than the grey-
green argillaceous cherts and cherty argillites common in
the typical variety of conglomerate described from Mount
Guyet-Alex Allan Creek. Chert clasts identical to those
within the conglomerate are found within the directly
overlying Visean limestone of the Greenberry Formation.
On the same island there is a dark grey variety of con-
glomerate which has about 25% clasts, only half of which
are dark and light grey chert. The remainder of the clasts
are light grey and tan siltstones and purple to red ochre
siltstones rich in iron oxide. The clasts are granules to
fine pebbles and are angular to subrounded.

30

a *~ oe ee

Figure 19. Sandy conglomerate of the Guyet Formation.
A) Angular and subangular chert pebbles in quartz and
chert sand matrix northeast of Alex Allan Creek. (GSC
191016)

B) Limestone cobble in a foliated matrix like that from
a tributary of Alex Allan Creek. (GSC 191017)

The muddy conglomerate has the same clasts as the
sandy conglomerate, however, there is a greater diver-
sity in their size and percentage. In the Summit-Alex Allan
Creek area there are more basalt, limestone and siltite
clasts in the muddy conglomerate; they are also larger
(Table 11). Sutherland Brown (1957, p. 33) described this
type of conglomerate from Summit Creek where 1 m
boulders of grey-green aphanitic basalt occur near the
base of the Guyet Formation. Near the mouth of the first
west-draining tributary to Alex Allan Creek similar vol-
canic clast-rich muddy conglomerate is interbedded with
the sandy conglomerate. The section along this creek is
described below.

The calcareous volcanic clasts contained in the con-
glomerate of this section are similar to the volcanics of
the Waverly Member. The large volcanic boulders at the
base of the muddy conglomerate of Summit Creek resem-
ble the Waverly flow at the base of the conglomerate
along Alex Allan Creek. Monotonous sandstone and
sandy conglomerate 235 m thick occurs 250 m south along
strike of the above section. Muddy conglomerate