Moose River Basin: geology and mineral potential - Geology Ontario

Moose River Basin
definitely whether the lignite occurrences were suitable for commercial use
and to study the other known mineral deposits of gypsum, iron ores, clay, and
shale.
It is interesting to note that in most of the early reports there are many ref
erences to the occurrences of lignite in the James Bay Lowland, giving the im
pression that deposits of this important fuel are abundant and widely scattered
throughout the region. This in fact is not the case. In the Moose River Basin of
the James Bay Lowland, beds containing carbonized plant material are of two
types and belong to two different geological periods. One is the true lignite of
the Cretaceous Mattagami Formation found in association with fireclays and
silica sands. The other is more appropriately described as peat and is found in
the Forest Peat Member of the Pleistocene Missinaibi Formation (Skinner
1973). In the early days of exploration of the James Bay Lowland the distinc
tion between true Cretaceous lignite and the Pleistocene peat was not recogniz
ed. The majority of the exposures of'lignite' reported in the early literature are
actually peat deposits of Pleistocene age.
Baker (1911, p.223,230,237) considered all lignite deposits of the Matta
gami River basin to be of Pleistocene age. Interestingly enough, Baker (1911,
p.234) remarked that "...the lignites of the Moose region are, considering their
recent age, in a remarkably advanced state of carbonization..." In retrospect
this is not surprising, for these were much older (i.e. Cretaceous) in age. One of
the primary objectives of Baker's studies was to investigate reports circulating
during the winter of 1909-1910 that real "coal" had been found on the Matta
gami River resulting in staking of several claims. When Baker reported that
the so called "coal" offered few economic possibilities no further staking took
place. Baker's report is an important document for it describes, in greater de
tail, the iron deposits of the Mattagami River, first reported by Bell (1877).
It was during an investigation of the clay and shale deposits on the Matta
gami River by Keele (1920) that the first recognition of deposits of Cretaceous
age was made. The clays were found associated with lignite and silica sands
and Keele, for the first time, recognized the age of the clay-lignite-silica sand
deposits as "undoubtedly of pre-glacial age, of more recent origin than Upper
Devonian". A collection of plant fossils from a sandstone bed included in the
clays was identified as "...not younger than Kootenay, but may be older...", by
the paleobotanists of the United States Geological Survey. Thus the name Mat
tagami series was introduced in the literature for the Cretaceous clays of the
Mattagami River. Dyer (1929) went on to define the Mattagami Formation
which included the associated lignite and silica sands. The Lower Cretaceous
age of the Mattagami Formation has since been' confirmed by several paleobotanical
studies e.g. W.A. Bell 1928; Hopkins and Sweet 1976; Norris, Telford,
and Vos 1976. Keele, through a series of publications during the years 1920-
1922 laid the foundation for many of the future activities centered on the clay
and silica sand deposits of the Missinaibi and Mattagami Rivers (see below).
About the same time attention was focussed also on the pre-Cretaceous rocks of
the James Bay Lowland. Following Parks' (1899; 1904) early work, Savage and
Van Tuyl (1919), Williams (1920), and Kindle (1924) produced the basic frame
work for the Paleozoic stratigraphy of the region and Cross (1920) studied the
iron ore deposits of the Abitibi-Mattagami area.