Moose River Basin: geology and mineral potential - Geology Ontario

Lignite and Industrial Mineral Resources
alumina content d.4.5% of A12O3) and high refractoriness (P.C.E. 32) reflect the
quartz-rich nature of its sandy fraction (34.89fc 4- 325 mesh). In this context the
plasticity is surprisingly low. This clay lends itself to either blending or benefi
ciation since very little deleterious material is present. Only the physical char
acteristics (e.g. size grading) need to be improved.
Clay 11 (40.8 - 44.6 m) is a yellowish-brown kaolinitic clay with a substan
tial amount ^59fc) of oolitic siderite. The predominance of this siderite in the
coarse fraction suggests that beneficiation will improve brightness (26.39fc), ref
ractoriness (P.C.E. 26) and alumina content (23^0.
Clay 12 (44.6 - 47.7 m) is a brownish grey kaolinitic clay which seems to be
colored mainly by the presence of lignite (G.8%). The refractoriness is high
(P.C.E. 31) and the percentage of coarse material low d.6% 4-325 mesh). Test
ing of the firing characteristics is necessary to determine possible uses for this
clay
Ċlay 13 (50.8 - 53.1 m) is a light brown kaolinitic clay with a high content of
alumina (30.59fc of A12O3) and a correspondingly high refractoriness (P.C.E. 34).
In the coarse fraction (Q.3% + 325 mesh), minute quantities of siderite and he
matite occur. A brightness of 25.79fc suggests that testing for firing characteris
tics (burnt color) is necessary to determine the ultimate use of this high quality
clay
Ċlay 14 (53.1 - 57.5 m) is a light-brown kaolinitic clay with characteristics
very similar to Clay 13. Clays at this level should be treated as one unit with a
total thickness of 6.7 m.
Clay 15 (75.4 - 78.5 m) is a pale-yellowish-brown kaolinitic clay with me
dium plasticity. The coarse fraction (G.5% -t- 325 mesh) contains quartz, mus
covite, and siderite in almost equal percentages. Bleaching raises the bright
ness of clay 15 from 29.29fc to 3S9c. Refractoriness and alumina content have not
been determined.
CLAY FROM WATER SAMPLES
The sampling routine in the reverse circulation wet-drilling process called
for sampling overflow drill water when the milky color indicated excessive loss
of a fine clay fraction. This sampling was aimed at recovering some of the white
kaolinitic clay frequently associated with quartz sand in the Mattagami For
mation. The presence of this clay is repeatedly mentioned in drill logs (Rogers
etal. 1975). The following samples were taken and analysed:
Drillhole 75-01 — (sand 1) 14,15; (sand 2) 20, 22;
(sand 3) 23,24,25; 36,38,42,45.
Drillhole 75-05 — (sand 9) 79.
In both drillholes clay associated with quartz sand is predominantly kao
linitic clay of excellent crystallinity with fine quartz. In the upper part of drill
hole 75-01 (samples 14,15, 20) there are, in addition, minor amounts of calcite
and dolomite. Brightness of these clays has been determined for samples 01-23,
24, 25, 42 and 05 - 79. It ranges from 71.1 percent in sample 01-42 to 91.1 per
cent in sample 05 -79.
These results contrast sharply with analysis of clay retained with sand in
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