92

This mineralized occurrence lies 200 feet below the west edge of the heavily mineralized rock as exposed at the surface. The end of the tunnel is cut in magnetite wh ch shows solidly along the west wall for 75 feet and for 45 feet along the east wall. The face of the tunnel is in magnetite and les 300 feet beneath the surface and, in plan, 45 feet west of the west edge of the large ore-body in which the lower of the two quarries has been opened. The ore penetrated by the tunnel lies beneath the zone of highly mineral- ized rock exposed at the surface, but not beneath the outcropping of the ore-body. There is no direct evidence that the ore in the tunnel and that at the surface belong to one continuous mass.

The character of the ore exposed in the western, lower quarry is as follows, as stated by McConnell.

“The magnetite is coarsely crystalline, breaks with a rough fracture, and is seldom free from impurities. Marcasite in thin, short, radiating plates concentrated in places along narrow bands resembling veinlets, is conspicuous from its contrasting colour, although the percentage present is small. Some pyrite is also present, and occasionally garnet and chal- copyrite. The non-metallic impurities include dark areas made up mostly of epidote, garnet, and hornblende, and a number of small, light- coloured areas filled mainly with calcite and quartz. The latter are con- sidered to be cavities formed during the crystallization of the magnetite and subsequently filled up. They are usually lined with garnet and con- tain some epidote and occasional cubes of pyrite in addition to the main valcite-quartz filling.”

In the steep face of ore on the north wall of the lower quarry, well within the ore mass, the dark areas referred to by McConnell and which apparently represent altered country rock, vary in size from mere specks up to others 1 to 2 yards in diameter. Calcite is also conspicuous in specks and splotches, some several feet long. The proportion of this barren material to ore is difficult to estimate, but by area it would seem to lie between 1 to 8 and 1 to 4. Areas of the ore are especially rich in sul- phides, others are nearly free of this material, but in general at least a speck of sulphide is visible in each area of 4 square inches. The ore penetrated by the tunnel resembles that found at the surface save that it seems to carry much smaller quantities of sulphides and waste materials. A sample across the face of the tunnel was taken and assayed by Whittier; the results are given in column 1 below. ‘An average sample . . . . along the tunnel” taken by Lindeman gave the results presented in column 2 below. A “general sample along the 75 feet of magnetite exposed in the lower tunnel” taken by McConnell, yielded the results shown in column 3.

COrNye Roos

Origen cane ee reene

1 Op. cit., p. 83.