CROESUS
High grade Gold from the Croesus mine (>10,000 opt)
The Munro-Croesus property includes the high grade past-producing Croesus mine (1915-1933). The mine is known to have produced some of the highest grade gold ever mined in Ontario. The Ontario Bureau of Mines (1919) reported that “765 pounds of ore taken from a portion of the shaft yielded $47,000 worth of gold”. This represented a grade of 5,944 oz gold per short ton (203,771 g/tonne) at a gold price of $20.67 per troy ounce. Five gold samples purchased by the Ontario Bureau of Mines for exhibition purposes and now in possession of the Royal Ontario Museum weigh 85 pounds collectively and contain 480.7 ounces of gold or 11,310 oz gold per short ton (387,727 g/tonne).
The Munro-Croesus property consists of 22 patented mining claims and leases (416 ha), located 75 kilometers east of Timmins, Ontario and within the influence of the prolific Porcupine-Destor Deformation zone that stretches from Timmins, Ontario for more than 200 kilometers into the Province of Quebec. In 2008, Constantine acquired a 100% interest in the 65 claim (1024 ha) Four Corners property located 1.2 kilometers to the east of the Munro-Croesus property. The new acquisition straddles the area between the prolific Porcupine Destor Fault Zone (PDDZ) and the Pipestone Fault Zone, and is within the same sequence of rocks that hosts the high-grade Croesus Mine and the past producing Holt-McDermott and Holloway Mines (>2.0 million ounce combined production) located 25 kilometers to the east.
Past Production
Records for past production are reported in personal journals of prior owners and operators and the Ontario Department of Mines. In 1915, an inclined shaft was collared on the high grade gold quartz-vein outcrop found in 1914. The inclined shaft was 425 feet in length and reached a vertical depth of 125 feet. The north-south striking (shallowly east dipping) high grade Croesus gold mineralization was mined from the shaft and from lateral development on the north and south sides of the shaft. The extent of the vein to the north is limited by a geological contact and was terminated on the south side by an east-west fault. Early production as recounted by Mr. Julius Cohen, production mining engineer at that time, consisted of both onsite milling and hand reduction of visibly high-grade vein material that was shipped directly to the Royal Canadian Mint. About 1,000 pounds per week were shipped during 1915-1917 and the early part of 1918. This type of production ceased when the fault was encountered. No grade can be determined for these high-grade gold shipments. In 1923, the owners milled some “clean up” mineralization. Other small milling campaigns continued sporadically up to 1936 and produced gold from pillars, fault material and surface dumps. The tailings for all these operations were subsequently trucked off-site and processed at the Pamour operation in Timmins (no data available). The Ontario Department of Mines reports the total historical gold production from milled ore was 14,854 ounces gold from 5,333 short tons, for an average grade of 2.78 oz gold per short ton (95.3 g/tonne). This does not include the high-grade gold ore shipped directly to the Royal Canadian Mint for processing.
Geological Setting
The geological setting and alteration signature of the high grade Croesus gold vein at the Munro-Croesus property is similar to the original high grade gold vein discovery at Goldcorp’s Hoyle Pond mine in Timmins that has produced over 2.4 million ounces to date and remains one of Goldcorp’s higher grade operations. Garfield MacVeigh, President of Constantine was responsible for the gold program that drilled the discovery hole at Hoyle Pond for Texas Gulf in 1980, which graded 34 oz/ton over 1.0 meter. Of particular significance is the presence of so-called “gray zones”, a very distinct and unusual alteration found adjacent to gold bearing veins. The gray zones contain carbon, which may have catalyzed precipitation of gold during ore formation and be responsible for the exceptionally high grades observed at both Croesus and Hoyle Pond. At the Croesus mine, high-grade mineralization occurs at the intersection of laterally continuous veins with a sulphide (and carbon) rich phase of the Croesus flow (see detailed geology map). High-grade gold is also known to occur at the contacts between flow units.
The high-grade Croesus vein was mined up to an east-west trending fault and its faulted offset has not been discovered to date. Recent drilling by Constantine has identified gold-bearing veins on the offset side of the fault and new vein systems at depth below the historic mine workings that share the same alteration, and stratigraphic and structural setting as the mined Croesus vein. With very few holes ever penetrating deeper than 100 meters on the property, the depth potential of the system remains virtually untested. Future exploration efforts by Constantine will focus on targeting these environments. Constantine management believes the larger structural setting underlying both the Munro-Croesus and Four Corners properties is very permissive for classic Timmins style gold mineralization and will be the focus of additional work outside the immediate Croesus mine area.
Project Photos
