The Toad River map area, situated 150 kilometres northwest of Fort Nelson in
north-central British Columbia, contains 10 documented mineral occurrences.The
terrain varies from the rugged Muskwa Ranges of the Northern Rocky Mountains in the
southwest, through the Rocky Mountain Foothills to the relative lowland of the Liard and
Alberta plateaus to the north and east, respectively. The Alaska Highway passes through
the southwestern corner of the area.
The map area is underlain by Proterozoic and Paleozoic sedimentary rocks of
Ancestral North America, which are covered to the east by Mesozoic overlap assemblages.
With the exception of a minor surficial deposit, all the mineral occurrences are in
Paleozoic rocks, and most of these deal with Mississippi Valley-type stratabound barite or
fluorite mineralization in Devonian carbonates. There are two areas of interest. The
mountains immediately northeast of Muncho Lake Provincial Park are underlain by gently
folded and thrust-faulted Silurian and Devonian rocks, including dolostone and limestone
of the Middle Devonian Stone and Dunedin formations, respectively. The BV
developed prospect (094N 002) comprises a large body of medium to high grade stratiform
barite in Stone Formation dolostones. A provisional estimate of "inferred
reserves" in 1967 was 100 million tonnes with an indicated grade of 65 per cent
barite. The Mo
developed prospect (094N 008), 3.5 kilometres to the north, has a very similar
character and stratigraphic setting. Potential reserves in 1979 in the most viable part of
the deposit were 3.4 million tonnes grading 34.7 per cent barite. In close proximity to
the BV and Mo deposits are the smaller Mun
barite prospect (094N 009), and the Snow
showing (094N 003) where fluorite occurs in Dunedin Formation limestone.
The other area is in another belt of Devonian rocks, 70 kilometres
to the north, in the Caribou Range. Here, the Dan group of claims contains several
occurrences (094N
004, 005,
006
and 007)
of disseminated fluorite-barite mineralization, in the form of bedded replacements or
veins, all in Dunedin Formation cherty and argillaceous limestones.
Ten kilometres to the northeast, the minor Scat
showing (094N 010) consists of small amounts of sphalerite and galena associated with
cherty nodules in black, baritic slate of the Upper Devonian to Mississippian Besa River
Formation.
The Wishing
Well showing (094N 001) consists of weakly radioactive calcareous tufa, which has
been deposited around cool springs.
