99

ore mass of the tunnel may be vertically below the body outcropping at
the surface. Such a condition would give further weight to the opinion
that the ore exposed at the surface and in the tunnel belong to one and
the same body, but would not demonstrate this to be the case, since there
is no doubt that in the general area masses of magnetite abruptly end or
grade into impregnated rock not rich enough in magnetite to constitute
ore. If it be assumed that the ore masses at the surface and in the tunnel
belong to one continuous body of uniform cross-section, then the ore-body
between the level of the quarry floor and that of the tunnel, would contain
in the neighbourhood of 300,000 tons. McConnell, making the same
assumption, estimates that the tonnage would be 1,366,400 tons, but this
estimate is based on the view that the ore-body at the surface has a length
of 300 feet and an average width of 80 feet. The adoption of surface
dimensions as large as this involves including much low-grade rock and
considerable barren diorite. The view advocated that the ore-body is
much more limited in size is corroborated by the results of an examination
of the property made for the owners by F. H. Shepherd and published in
the form of a map accompanying a report by Lindeman.!

In the case of the Paxton ore-body, practically nothing is known
beyond its surface extent. The two open-cuts at the foot of the south
face show that for a vertical space of a few feet the boundary is vertical.
Possibly the boundaries everywhere are vertical or nearly so. It would
seem safe to assume that the mass everywhere continues downwards to
at least the level of the foot of the south face. Making such an assumption,
the amount of ore in all probability would not be less than 300,000 tons.

The Lake ore-body outcrops with an area of 20,800 square feet. Prac-
tically no development work has been done in connexion with this mass.
The contacts seem to be vertical planes and it seems reasonable to assume
that ore extends in depth to at least the level of the lowest point now
visible on the south face. Under this assumption, at least 90,000 tons
of ore might be considered present.

The total amount of ore that, with varying degrees of probability,
it seems permissible to assume as probably present in the Prescott, Paxton,
and Lake deposits, is, in round numbers, 700,000 tons. This quantity,
however, may not be all first-class ore. Writing in 1902, Carmichael’
stated with reference to the operations then being conducted on the Pres-
cott ore-bodies that . . . . ‘‘as the ore is mined on royalty, only
that running 50 per cent iron, or over, is shipped. With such sorting,
only about half of the ore mined is shipped”. . .. McConnell es-
timated that the Prescott, Paxton, and Lake bodies might contain in the
neighbourhood of 3,500,000 tons provided that the bodies... “ex-
tend downwards for a distance equal to their exposed surface length”

but the same author is careful to state that the ore-bodies are

of a type which - . . =. ‘are characteristically irregular and un-
certain in outline. Furthermore, the district has been subjected to almost
continuous erosion . . . . (for an extremely long period of time

and consequently the ore-bodies) have been partly destroyed, and the
portions remaining may represent either the roots or the tips of large
masses”. . Another estimate of the ore tonnage is given by
Stansfield? who from notes furnished him by the B. L. Thane Company,

a Op. cit.
2 Gaachnale H.: Ann. Rept., Minister of Mines, B.C., 1902.
3 Department of Mines, B.C., Bull. No. 2, p. 31 (1919).