193

Most of the exploration, including the tunnel, was done prior to 1903, as geological sketches of the workings are given by Carmichael in 1902 (6, page 215).

In 1922, W. M. Brewer was called upon to furnish some iron ore for experimental purposes under the provisions of the ‘“Iron-Ore Supply Act, 1919” and he secured about 10 tons from the old dumps at the entrance to the adit on this property. This ore was shipped to the Vancouver Engineering Works to be mixed with scrap iron and steel in their electric furnace operations.

GEOLOGY

_ The deposit occurs within a country of white to grey limestone, intruded in places by hornblende diorite of the Beale formation. In only a few places are bedding structures visible in the limestone. One of these is at the bottom of the winze, 30 feet from the portal of the tunnel, where the stratification of the limestone is almost horizontal; and another is in the large central exposure of limestone, where indications also point to a general horizontal attitude or low angle of dip. _ The flatness of the bound- aries of several magnetite exposures in limestone also points indirectly to the above conclusion.

Apart from one or two small surface exposures near the bluff at the western end of the deposit, no diorite is exposed at the surface, whereas on the other hand, the inner 75 feet of the tunnel is in solid hornblende diorite. This fact, combined with the distribution of the two rocks as shown on Figure 31, leads to the inference that the ridge on which the deposit occurs is underlain by a boss of diorite whose contact with the limestone undulates about the plane lying at a shallow depth below the surface. Garnetized limestone and solid masses of brown garnet occur in some places near the intrusive contact; in other places, silicified limestone with bountiful disseminations of pyrite occurs.

OCCURRENCE OF THE MAGNETITE

Magnetite occurs in solid masses of irregular shape, mainly within the limestone or associated with garnetized portions of it. In the tunnel, the lode is observed to occupy a position between diorite on the east and limestone on the west, and to have similar relations to those rocks as were exhibited by the magnetite deposits of Bugaboo creck. In no other part of the property is it seen in contact with diorite, but the presence within the magnetite of residual fragments of limestone, together with its occurrence in irregular-shaped masses in association with the character- istie contact silicates brands the lode as a contact deposit.

The irregular structure of the deposit may be illustrated by the follow- ing observed facts: (a) A few feet southwest of the portal of the tunnel, the magnetite is in sharp contact with a mass of limestone, the contact dipping to the northeast under the magnetite; (b) within the tunnel, the contact of diorite and magnetite dips southeasterly with the diorite on top of magnetite; (¢) the innermost 30 feet of the tunnel is in diorite, but 75 feet above this on the surface is a stripping and open-cut exposing magnetite mixed with limestone, but no diorite; (d) the section on line E-F (Figure 31), shows a thickness of about 10 feet of magnetite lying with a nearly flat contact on top of limestone and its contact metamor-

phosed phase.