Deposit/Occurrence Name: Emerald Lake Prospect
Primary Commodity: Cu
Secondary Commodity: Ni
Nearest Town or City: Elliot Lake
Mine or Exploration Site: Exploration
Ore-Grades: 0.07% to 0.357% Cu, 0.0617% to 0.1507% Ni, 0.11 to 0.72 oz. Au
Estimated Tonnage: N/A
Mineralization: Disseminated pyrite, pyrrhotite, chalcopyrite
Exploration and History
Pickering Uranium Mines, Ltd. would additionally become renamed in toe Pickering Metal Mines, Ltd in 1955. Most of this was followed by the staking of two additional properties that were being explored at the time in Mack Township. The largest of these properties that was place under early exploration stages was the Emerald Lake Group of claims. Exploration work at this time was mainly being achieved from land surface, and also on water that was done during the winter season.
Hole No. 1 at this time had mainly consist of water from 0.00 to 95.0 feet and mud and silt would be additionally intercepted from 95.00 to 108.0 feet. This also resulted in intercepting Lower Mississagi Quartzite from 108.0 feet to 526.0 feet before the hole had ended at 526.0 feet.
Hole No. 2 had rather consisted of a casing from 0.00 to 3.00 feet, and Lower Mississagi Quartzite was intercepted from 3.00 to 714 feet. This also included an intercept of Lower Mississagi Quartzite Argillite, quartzite from 714.0 feet to 740,5 feet. It was also from 740.5 to 1,207 feet where Lower Mississagi Quartzite was interacted before the drill hole had ended at 740.5 feet.
Emerald Lake Mines, Ltd. would additionally stake this ground from 1965 to 1966, where resulted in further completing exploration work on the Emerald Lake Cu-Ni Prospect. Most of this was aimed at conducting surface exploration work on the south-east side of Emerald Lake. It would additionally result in further trenching the ground, and conducting ground geophysics on this property at the time. This would result in further exploring the area by conducting a diamond drilling program of 18 surface holes, totalling 547 feet in length.
Some of the best intercepts at this time had came from diamond drill hole 66-3, that intercepted nil in gold, silver and nickel, and 0.07% Cu from 23.00 to 25.00 feet over 8 to 12 feet footage. Diamond Drill Hole No. 66-4 had returned nil values in gold, and silver, and 0.357% Cu, and 0.0617% Ni. Intervals of 12 to 13 feet, had additionally assayed nil in Au and Ag, and 0.027% Cu, and 0.1507% Ni. Diamond Drill Hole No. 66-13 returned nil in Au, Cu, and Ni, and 0.11 oz. Ag over 5 feet. A grab sample at this time was additionally taken which resulted in assay values of 1.25% Cu and 0.72 oz/ton Ag.
The rock types of this general area are rather Mississagi Quartzite with some argillite thats in place. Diamond drilling at depths of 3.00 feet to 714.0 feet had largely intersected Lower Mississagi Quartzite. It was from 714 feet to 740.5 feet where drilling had intercepted Lower Mississagi Quartzite, Argillite, and more quartzite. This is overlain on top of the Lower Mississagi quartzite that was intercepted in drilling from 740.5 feet to 1,200 feet. Most of the mineralization in the general areas is known to mainly consist of disseminated pyrite, pyrrhotite, and some chalcopyrite is also present in a chlorltized shear zone that exposed for 25 feet along strike and 10 feet across strike.
The Lower Mississagi Formation is exposed as the following, with the upper members that are generally exposed between to faults as the northwest end of Rosssmere Lake in McGiverin Township. It also commonly a belt, that partcially interrupted by faults and diabse intrusions, extending from the southwest corner of McGiverin Township by Intersect, McFadden, Hastie, Surpise Lakes and the North Shore of Lauzon Lake to the Pronto Uranium Mine. Its from the east end of Long Lake that's northeast of the Pronto Mine along Spragge Creek swining east along Waugush Lake to the vicinity of Highway # 108 where the formation is cut by overlap against a basement topographic high. The entire Lower Mississagi Formation is also only exposed in vicinity of Surprise Lake and the east end of Lauzon Lake, and to the east of Waugush Lake. In addition to surface data there is considerable information from diamond drilling.
The Lower Mississagi Formation rather rests with uncomformity on the surface of the Algoma Granite and relicts of the post-Algoman soilds that are normally preserved. The actual base of the Lower Mississagi Formation is marked by the onset of sorting, and bedding. This usually consists of beds of quartzite pebbles that are largely present with in the contact that may be difficult to identify particiularly in drill core. The lowermost beds which generally consist of poorly sorted, angular to subangular quartzite and microline grains that are up to 1/4 inch across, set in groundmass of continued fragments and sericite, while the latter probably had derived from the weathered granite. In some cases, pyrite is largely present within the quartzite that constitutes as a sulphide mineral but is not present in all geological environmental conditions. These foremost beds are considered to crudely grade into finer grained more sericitic material that's more significant towards the top. Interbedded wit the arkosic quartzite are beds up to 4 inches thick consisting largely of sericitic feldspar debris and quartz. On weathering these beds take on a much yellow green colour that's more pronounced than that of the quartzite. On certain outcrops these rather green bands are clearly defined by the bedding. The upper most surfaces of the quartzite and green band may also show ripple marks.
Quartzite beds are generally scattered throughout the arkosic beds or concentrated into bands generally 1-3 inches thick. These pebbles are subangular to well rounded, well sorted, and are almost entirely of vein quartz, although pebbles of chert, jasper, and occasionally, deformed clasts are similar to the sericitic green beds. Pyrite is commonly conspicuous component of the matrix of the pebble bands. The pyrite may be euhedral or anhedral, and is largely restricted to the matrix it self. Some of the main accessory minerals consists of monazite, magnetite, apatite, and zircon. These pyritiferous oligomictic pebble bands are slightly radioactive that are generally less than 3 times background. They are also similar in type to the uranium-thorium ore of the Blind River Group.
The Lower Mississagi Formation is there for determined as dominantly coarse-grained arkose-quartzite sequence derived from weathered granite and deposited in much shallow water by southeasterly flowing currents. A zone of greater thickness may also lie in the most southwest part of Long Township. Scattered pebble bands and radioactivity are some of the main characteristics of the lower part of the formation. Radioactive conglomerate that's to the east end of Lauzon Lake had additionally sparked the Blind River Staking Rush.