Omineca Mining and Metals goes placer mining at Wingdam, British Columbia
Omineca Mining and Metals Ltd. [TSXV-OMM; OTCBB-OMMSF] has begun recovery and processing of gold-bearing gravels at the Wingdam Paleoplacer project in the Cariboo mining district in south-central British Columbia. The company recovered 10.25 ounces of placer gold with 90.9% gold purity (909 fineness) from the first approximately 2.5 metres of advance at the bedrock contact of the paleochannel in crosscut No. 3.
The initial thickness of the gravels exposed in the face overlying bedrock was approximately 0.5 m to 1.0 m, which is expected to increase in thickness as the bedrock rim dips toward the centre of the channel floor. These initial recoveries are still, in large part, at the bedrock interface and are comparable with recoveries in the similar peripheral area of the channel at the 2012 bulk sample (crosscut No. 1) location. Additional updates will be provided once the miners reach the anticipated highest gold grades across the central portion of the channel.
Omineca’s joint venture partner, D&L Mining, has extended the haulage/access drift in bedrock approximately 70 metres downstream of the 2012 crosscut No. 1 location with a slight downward slope to intersect the lower portions of the paleochannel floor. Crosscut No. 3 is being driven from the haulage/access drift approximately 30 metres downstream from crosscut No. 1. In accordance with the engineered mine plan, D&L is implementing artificial ground support which includes a series of spilings (metal rods) encased in grout, which are being placed above the area to be mined within the paleochannel. Crosscut No. 3 is a 3.5 m by 3.5 m excavation that will span the entire width of the channel.
A second new crosscut heading, No. 4, has been driven from the haulage/access drift a further 20 metres downstream and is now near the bedrock/paleochannel contact, ready for development in tandem with crosscut No. 3. Once both crosscuts have reached the centre of the paleochannel, mining activities will be initiated both up and downstream from each crosscut within the channel.
In this type of paleochannel setting, the largest amount of placer gold tends to be in the lower points of the central portion of the paleochannel where, through natural waterborne gravity sorting, the highest concentrations of heavier materials, like gold, settle. This feature was noted in the bulk sample crosscut where of the 173 ounces recovered from a 23.5-metre crosscut, approximately 75% of that amount was produced from a 5.5-metre section in the middle of the channel.
All material excavated from the contact forward is being run through the wash plant consisting of a simple trommel/sluice system with the concentrate this produces run over a shaker table in the assay lab for final gold recovery. Some important observations are as follows: the gravel-bearing paleochannel has been thoroughly dewatered; gravels and cobble within the paleochannel are dry, with no visible flowing water.
The grouted spiling ground support above the excavation area is proving effective. Initial material recovered from the channel contact consisting largely of bedrock, and some gravels higher up from the floor, has yielded over 10 ounces of placer gold from the first 2.5 metres of advance.
Recoveries of gold from the initial rounds in this crosscut are comparable with those noted at this phase of the upstream 2012 bulk sample crosscut.
Of special note, and consistent with the results of the initial bulk sample crosscut, the easily recovered gold is all very coarse (nuggety), with very little fine gold particles (less than one millimetre (mm) diameter), and exhibits characteristics of very low transport distance from lode source – estimated at less than one kilometre.
The price of gold in Canadian dollars has nearly doubled since the Wingdam joint venture was initiated for this operation.
Omineca Mining and Metals’ flagship Wingdam gold exploration and placer recovery project is located along the Barkerville Highway 45 km east of the city of Quesnel. The Wingdam property includes mineral tenures totalling over 61,392 hectares (613 km2) and in excess of 15 linear kilometres of placer claims, both encompassing the Lightning Creek valley where topographic conditions created thick layers of overburden, which preserved a large portion of a buried paleochannel containing placer gold-bearing gravels. Omineca also has an exploration and diamond drill program currently under way exploring for the potential multiple hard-rock sources of the placer gold at Wingdam.