LOCAL DISTRIBUTION.
Valuable argentiferous veins were known in 1908 only in the Gowganda district, and, so far as yet known, discoveries have been confined to the diabase west of that lake. Most of them occur in the southern portion of the central diabase strip which lies a short distance from the shore and extends northward for about seven miles from Elkhorn lake. On one of the Mann claims (T.R. 1966), now owned by Messrs. Foster, an east and west vein averaging 4ʺ or 5ʺ in width had been traced for 300 feet, the original discovery being made in the exposed face of a low diabase wall. At its surface the vein material had been weathered out for a depth of about 15ʺ and the cavity filled by a brownish mass of the decomposed matter mixed with vegetable mould and sand. Nuggets of mossy or arborescent silver were scattered richly through this dirt, and a fairly continuous spine of the same metal, sometimes an inch thick, extended along the middle of the crevice. A test pit sunk about 8 feet, but barricaded at the time of the writer’s visit, had exposed, according to Mr. Mann, silver and smaltite in a calcite vein. On the adjoining claim (T.R. 1982), a vein of massive smaltite about 1ʺ wide was seen; a little silver had been found at its surface and streaks of argentite and disseminated grains of smaltite were seen in the wall rock. Aplite dikes on another claim were found to be stained by cobalt bloom, and full of disseminated chalcopyrite.
The properties owned by Messrs. Crawford and Dobie about half a mile farther south were not visited, but were generally reported to be of about the same richness as that in T.R. 1966. Immediately north of Hanging-stone lake Mr. F. A. McIntosh was conducting active prospecting in a coarse gabbroid, locally syenitic, form of the diabase, intersected by aplite dikes. A discovery of native silver has been made since then and the property sold to Messrs. F. R. Bartlett & Co., of Toronto, together with other claims located between the north-east and north-west arms. Other discoveries are reported just south-east, also a short distance north of Milne lake.
No silver had been obtained in the eastern diabase strip, although the geological conditions appear identical and calcite veins are abundant. An exceptionally large vein, about 18ʺ wide, and traceable across two adjoining claims was seen on the property of Messrs. McLaughlin and McIntosh, about half a mile north-east of the north-west arm. Mineralization in it near the surface was very slight. Several veins carrying small amounts of chalcopyrite, pyrite, bloom and smaltite were seen on the properties of Messrs. Elstone and Reilly (T.R. 1961, 1962 and 1903). In one of them small amounts of bismuth are present; another contains an unusually heavy black substance which proved to be calcite filled with minute crystals of magnetite.
In the western strip less exploration had been performed and little could be learned about the ore deposits. Loose pieces of native silver had been found by W. H. Margueratt in narrow fissures on M.R. 1798, but the vein material was not exposed.
Outside the Gowganda area systematic prospecting was in progress at only one point—Wapus creek. Under the management of Mr. Robert Lett a group of nine claims was being stripped and trenched, with the result that numerous calcite veins had been traced through a diabase showing the same complex intermingling of basic and acid phases and aplite dikes as at Gowganda. Chalcopyrite and cobalt bloom were abundant, and smaltite had been found as disseminations in the wall rock. Lumps of native bismuth weighing several ounces had been taken from a fissure in an aplite dike, analyses of which showed it to contain silver.
Tentative exploration was being conducted along Duncan lake and east of Firth lake, but not with the closeness and persistence which the topography of these veins require. In general the veins seen on Duncan lake are exceptionally rich in quartz, and gash veins are common. Chalcopyrite, pyrite and galena are the most noticeable metalliferous minerals, but cobalt bloom stains are frequently observable. So far as known no attention has been given to the large diabase body between Duncan lake and the West branch, although its size and varied composition are thought to make it a desirable prospecting ground.