Moose River Basin: geology and mineral potential - Geology Ontario

Moose River Basin
mounted Acker drill, designed to sample deep overburden and bedrock. A re
verse circulation method using 69 mm diameter standard Drilco dual tube rods
was employed to obtain chip and slurry samples at intervals of about 2 m. The
drills were operated continuously on two, 12 hour shifts. The drilling started on
February 4,1975 and was completed on March 27,1975.
The geophysical studies consisted of a seismic survey for 72 km and a resis
tivity survey for 84 km. Both types of survey were carried out along the road
north of Hambly Township base line and a resistivity survey was also con
ducted along the base line. Eight kilometres of combined surveys were done in
parts of the road south of Hambly Township base line where the road was
straight for at least 2 km.
During the summer of 1975, a helicopter supported outcrop reconnaissance
survey of the Moose River Basin was carried out and the lignite deposits at
Onakawana were re-examined (Telford et al. 1975). The objective of this work
was to determine which of the earlier reported occurrences of "lignite" outside
Onakawana were true lignites worthy of follow-up studies. It was determined
that, except for the reported occurrences along Coal River where it meets the
Missinaibi River, and those of the Mattagami River and its tributary Adam
Creek, most of the other occurrences were of Pleistocene peat. Palynological
analyses of samples collected from outcrops of the Mattagami Formation along
the Mattagami River near Smoky Falls suggested at least a late Middle or Late
Albian (Lower Cretaceous) age for the unit (Norris et al. 1976).
In 1975-76 another geophysical survey was carried out over the Onaka
wana lignite fields (Scintrex Surveys Limited 1976). The purpose of this work
was to determine whether existing geophyscial methods, particularly geo-electric
techniques (ground as well as airborne) can be used as search tools to locate
near surface deposits of the Onakawana type. The ground resistivity survey in
dicated that there was no appreciable difference between the resistivity of the
lignites and the clays associated with them. The airborne electromagnetic sur
veys indicated two regions of relatively high conductivity, one to the west of the
Ontario Northland Railway containing "within its confines" the known lignite
fields, and another area immediately to the east of the Abitibi River. The sec
ond zone included three anomalies and Scintrex considered them to be correla
tive with the anomalies over the known lignite fields at Onakawana.
In the Fall of 1977, three shallow holes were drilled on the anomaly loca
tions east of the Abitibi River (Verma et al. 1978). In this operation, the equip
ment was transported to Onakawana by rail car and camp was established at
the Onakwana railway siding. The movement of men and equipment between
camp and drill sites was by a Bell 206L helicopter. Hole 77-01 was 46 m deep
(Photo 1.4), 77-02 was 50 m and 77-03 was 51 m. Sampling was done by split
spoon sampler at intervals of about 2 to 3 m as well as by BQ wire line core bar
rel giving continuous core recovery. The drilling commenced on October 11,
1977 and was completed on October 22, 1977. This investigation did not result
in identification of significant quantities of lignite east of Abitibi River, but im
portant stratigraphic information was obtained which will be useful in plan
ning future exploration work in the Moose River Basin. Subsurface stratigra
phy on the east side of the Abitibi River is significantly different from that on
the west side, with Devonian bedrock forming local structural highs.
In late summer of 1978 the third major Mesozoic drilling programme was
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