Moose River Basin: geology and mineral potential - Geology Ontario

Moose River Basin
by Hamblin (this report), abundant lignite detritus in one sample at 116.3 m
may indicate a minor Cretaceous erosional residue between the Pleistocene
and the Middle Jurassic sediments.
Age and Correlation
A detailed account of the palynologically determined age of the Mistuskwia
Beds is provided by Norris (1977; this report). The u,nit is Middle Jurassic in
age and correlative with the Upper Gravelbourg, Sawtooth and Shaunavon
Formations of southern Alberta and Saskatchewan.
MATTAGAMI FORMATION
Keele (1920) proposed the name Mattagami series for nonlithified, lignite
bearing sands and clays overlying Upper Devonian strata along the Mattagami
River in the general vicinity of Onakawana. He was followed by Dyer (1928)
who designated these Mesozoic sediments as the Mattagami Formation. No
type section of the unit was proposed then, or has been proposed in any subse
quent studies, and no single exposure of the entire Mattagami Formation is
known. As noted previously, numerous drillholes in the Onakawana and
Smoky Falls-Hambly Township area have provided complete sections of the
formation and it may be useful to designate one or more of these as reference
sections.
Two of the better documented recent drillholes that could serve as refer
ence sections are the Hambly No. l hole (Figure 2.9), drilled by Aquitaine Sogepet
et al. (1973), and drillhole 75-06 of the Ontario Geological Survey winter
1975 drilling programme (Figure 2.8). Both holes intersected complete sections
of the Mattagami Formation and encountered a combination of lithologies that
is very typical of the unit. An added feature of the Hambly No. l hole was the
down-hole geophysical logging (gamma-ray; neutron activation) carried out
concurrently with the drilling.
Distribution and Thickness
Distribution of the Mattagami Formation in the Moose River Basin was
discussed previously. The lateral extent of the unit cannot be defined precisely.
However, it is thought to extend, virtually continuously, around the eastern
and southern margins of the basin from the Portage Island area in the north
east to Burstall Township in the southwest. The winter 1975 drilling found the
unit as far north as drillhole 75-02, about 50 km north of the Precambrian es
carpment. Surface exposures of the Mattagami Formation occur in the north
east near Portage Island and Onakawana, in the southeast along Adam Creek
(Photo 2.5) and the Mattagami River in Kipling Township, and along the Missi-
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