Pickle Lake
Northwestern Ontario, Canada
5. Pickle Lake
Geological Setting
The Pickle Lake area is a historical gold camp that has seen approximately 2.5 million ounces of gold production from three separate mines over a 60 year period beginning in 1934. It is situated in the Uchi sub-province of the Superior Structural Province, a gold-rich tectonic domain that also hosts the high grade Red Lake gold camp and numerous other significant gold occurrences. Over the 75 year history of gold exploration in the Pickle Lake gold camp, this is the first time that the entire land package covered by MetalCORP's claim have been held by a single company.
The Property covers 12 km of a major northeast-striking structural corridor known as the Tarp Lake shear zone. This structure transects a typical Archean greenstone assemblage of dominantly mafic metavolcanic flows, iron formation, and various mafic and felsic intrusive rocks. The shear zones have been the focus of intense hydrothermal alteration including carbonatization, sericitization, silicification and pyritization. Gold mineralization is associated with the altered shear zones in quartz-carbonate veins or in broad zones of disseminated pyrite mineralization.
Historical Exploration Work
The Property has been explored by individuals and companies including Placer Dome, Metall Mining, Esso Resources, Billiton and Dora Exploration. Numerous gold occurrences have been identified through this work although much of the area is covered by an extensive blanket of glacial drift resulting in very limited outcrop exposure. Broad areas of wet swampy ground, makes access difficult, which has inhibited historical prospecting work.
The most significant gold occurrence outlined by previous work is the Metcalfe Vein. It is reported that 25 drill intersections on the Metcalfe vein indicated an average width of 1.17m over a length of 320m with an average grade of 12.61g/t gold (0.37opt), (Source: Ontario Ministry of Northern Development and Mines assessment files). An article printed in the Northern Miner in November, 1979, "Dora Exploration may Drive Decline" reported that "the deepest hole, S-18, gave 6.0 ft. of 2.15oz. gold per ton at a vertical depth of 82m (270ft). Another hole gave 6.0ft. of 0.83oz. at a vertical depth of 101m (330ft)." Four other quartz veins were reportedly identified to run parallel to the Metcalfe vein also yielding visible gold. A gold bearing iron formation with assays as high as 9.5 g/ton (0.28 oz/ton) gold over 1.2m is also reported on the property.
On the southern part of the property, one historical gold showing, called the Mitchell, yielded values from grab samples, ranging up to 17.2 g/t gold (0.50 opt Au). A drill program in 1947 reportedly returned gold values of 11.0 g/t gold (0.32 opt Au) over a core length of 1.2m and 8.3 g/t gold (0.24 opt Au) over 3.7m. It is reported that a second showing, called the Esso zone has yielded assay values of 9.5 g/t gold (0.28 opt Au) over 1.2 metres.
At the north end of the Property historical drilling has yielded gold values of up to 7.20 g/t Au over 4.60m (0.21 opt Au/15ft) and 1.5 g/t Au over 36 metres (0.045 opt Au/118 ft). These intersections, in the Tarp Lake zone, were hosted by a zone of quartz-sericite carbonate-pyrite schist in the Tarp Lake Shear, which has a maximum thickness of 122m (400ft). A second gold zone, named the TL-7, yielded an average assay of 1.0 gpt gold in one old drill hole over a core length of 10 metres.
2003 Work Program
MetalCORP conducted work on the Property in 2003 and 2004. A $200,000 program was carried in 2003 and involved mapping, prospecting, sampling and trenching and was primarily focused on the Metcalfe vein. Later in 2003 a detailed airborne magnetic survey was flown over the entire Property to provided information to interpret bedrock geology in the overburden-covered parts of the property. The survey results aided in recognizing several targets based on interpreted structures and alteration zones related to magnetic lows.
Trenching on the Metcalfe Vein confirmed the presence of high grade gold in narrow quartz veins hosted by strongly carbonatized mafic volcanics and spatially associated with quartz feldspar porphyry intrusions. Sampling of the Metcalfe Vein yielded high grade gold assays, from grab samples of up to 2232.92 g/t (65.13 oz/t gold). Channel samples across the vein yielded assays ranging from 5.01 to 108.2 g/t gold over widths ranging from 10-20 cm. A new gold zone, called the Seven Zone, which contained two narrow quartz veins was discovered approximately 200 metres north of the Metcalfe Vein. One vein yielded 34.15 gpt gold (1.00 oz/t) in a 12 cm channel sample and the second vein yielded 21.56 gpt hold (0.63 oz/t) in a 10 cm channel sample. The veins in both zones are typically 10-15cm wide, spaced 5 metres apart and hosted by strongly carbonatized mafic volcanic rocks.
2004 Work Program
In 2004 work consisted of mapping and prospecting to investigate targets recognized from the 2003 aeromagnetic survey, followed by trenching of several new showings discovered during the program and a first phase diamond drilling program on the Metcalfe vein.
The prospecting work resulted in the discovery of a new gold showing on the southern part of the property called the Jigger. In order to better expose the showing, trenching over an area of 2500m2 was completed and revealed that a wide, strongly sheared and altered zone is host to quartz-carbonate veins. Grab samples yielded gold assays of 19.58, 21.04, 29.32, 40.68, 62.65, 83.73 and 95.63 g/t Au. Visible gold was noted in several samples. The shear zone is estimated to be a minimum of 50 metres wide and 600 metres long, coinciding with an airborne magnetic low anomaly. The showing is an bounded on all sides by an extensive swamp.
Prospecting work carried out by Billiton in the 1980's reportedly discovered a gold showing near the site of the new Jigger showing, which produced assays of 18.4 & 6.22 g/t Au. This zone has never drilled. Another showing was discovered 600 metres southwest of the Jigger, which produced an assay of 3.2 g/t Au, in a grab sample of material considered identical to the mineralization observed in the Jigger showing.
In August, 2004, a six hole, 2033 metre diamond drilling program was carried out to test three known mineralized zones located at or around the Metcalfe vein. Drill holes 01 and 02, tested the Seven Zone; holes 03, 04, and 05 tested the Metcalfe Vein; and hole 06, tested the Carbonate Zone. In the Metcalfe Vein and Seven Zone only narrow quartz veins containing low grade gold values were intersected, with the best intersection being a value 7.5 gpt Au over just 0.30 m in hole #05. Hole #06 in the Carbonate Zone, located 450m west of the Metcalfe Vein, intersected a broad zone of highly altered mafic volcanic rocks containing 2-10% disseminated pyrite mineralization that assayed 1.1 g/t gold over 12.0 metres.
The Company recommenced work on the Property in late September with a planned six hole, 1,800 metre diamond drill program on the Tarp Lake zone. This drilling is intended to following up on results from Inmet Mining diamond drilling in the late 1990's which included 7.2 g/t gold over 4.6 metres and 1.4 g/t gold over 36 metres. The Company also intends to drill the Jigger showing.
2009/2010 EXPLORATION PROGRAM
In early October 2009, MetalCORP extended its current exploration program at Pickle Lake to further test the Tarp Lake Shear Zone in the northern part of the Pickle Lake property. Seven drill holes were completed by the end of the program in late October, representing approximately 2300m of drilling. In previous work at the Tarp Lake Shear Zone in the mid-1990s by Inmet/Minnova, values of up to 7.2 g/t Au over 4.6 metres and 1.4 g/t Au over 36 metres were returned. The October 2009 drill sites were located beside an all-weather road, approximately 15 km north of the past-producing Pickle Crow Mine near Pickle Lake, Ontario.
The seven holes drilled as part of this first exploration phase are testing an Inmet/Minnova Induced Polarization (IP) geophysical anomaly. While assay results are pending, initial findings suggest that the program has extended the mineralized zone southward and to depth.
Initial Results from Current Drilling
Current drilling has encountered a strongly altered well-foliated sequence of felsic and mafic metavolcanic rocks. All of the drill holes show broad intervals (typically several tens of metres) of disseminated sulphides, mainly pyrite, which in previous drilling correlated well with the highest gold grades. Several of the most recent holes have intersected more pyrrhotite-rich "stringer" style sulphides (up to 20-25% total sulphides, based on visual assessment, with accessory sphalerite, chalcopyrite and, more locally galena.). Other parts of the property show good potential for shear zone hosted vein gold deposits, and for iron-formation-hosted gold deposits similar to those mined historically at the nearby Pickle-Crow deposit.
Next Steps for 2010
While MetalCORP's drill program for Pickle Lake has been completed for the 2009 field season, MetalCORP is formulating plans for a winter geophysical program which will follow rehabilitation of pre-existing grids established by a number of exploration companies between the late 1980s and 2004. A combination of effective geophysical surveys, including Induced Polarization (IP) and Magnetometer work, along with a thorough evaluation of previous work in light of MetalCORP's most recent drilling, should lead to a much clearer understanding of the geology and controls on the mineralization at the Pickle Lake property. This will allow MetalCORP to generate a number of intelligent, compelling drill targets to be tested in 2010.