The QR deposit is located 73 kilometres east of Quesnel, on the north side of the Quesnel River near Maud Creek.
The QR deposit is hosted by a thick succession of Upper Triassic basaltic, volcanic, volcaniclastic and epiclastic rocks of the Nicola Group. Basal flows, conglomerates and breccias grade upward into calcite-cemented tuffs and lapillistones. Calcareous black argillite and siltstone overlie the volcanic sequence. The pyroclastic rocks contain 5 to 20 per cent pyrite as delicate framboids and banded rip-up clasts. The sedimentary rocks contain up to 10 per cent fine-grained, disseminated pyrite. The whole sequence has been intruded by the Early Jurassic, zoned, monzodiorite QR stock and hornblende porphyry dikes.
Mineralization, consisting of native gold and sulphides, occurs in 3 discrete zones.
The Main zone is a discordant, 300-metre long, steeply plunging, northerly dipping (at 50 degrees) tabular body. The Main zone is truncated at depth by Wally's fault. Massive propylitic alteration, consisting of epidote, carbonate and chlorite occurs in the lapillistones and coarse tuffs. Disseminated to massive lenses of pyrite with 1 to 5 per cent associated chalcopyrite occurs within zones of propylitic alteration. The majority of the gold occurs in propylitically altered carbonate-rich rocks associated with pyrite mineralization. Fracture networks and stockworks in the basaltic flows, conglomerates and breccias contain 2 to 5 per cent pyrite with some associated gold and minor calcite. The Main zone contains an estimated 616,760 tonnes grading 4.4 grams per tonne gold will be mined by open-pit methods (Information Circular 1996-1, page 5).
The faulted extension of the Main zone, the North zone, occurs in the footwall of Wally's fault. Another zone, the East zone, appears to be a small unfaulted body. The grade of the North and East zones are comparable to the other zones but the ore is too deep to be economic at present.
The West zone, an elongate tabular body with a slight synclinal shape, is composed of propylitized basaltic tuff, breccia and interbedded siltstone. Discontinuous seams and lenses of massive pyrite with subordinate pyrrhotite, chalcopyrite and trace galena and arsenopyrite occur in these rocks. Coarse gold, up to 1 millimetre in diameter, has been observed in drill core from the West zone. The West zone contains probable reserves of 168,700 tonnes grading 6.64 grams per tonne gold and will be mined underground during the latter years of the mine's life (Information Circular 1996-1, pages 5,6). About 4500 tonnes have been mined and milled from the West zone pit yielding approximately 40,000 grams of gold (R. Lane, personal communication, 1996).
The Midwest zone is a tabular body with a moderate westerly plunge. In June 1996, Kinross Gold Corporation begam driving a ramp from the upper pit west wall of the Main zone to the hangingwall of the Midwest zone, a few hundred metres to the west. Production from the Midwest zone, with probable reserves of 440,800 tonnes grading 4.32 grams per tonne gold, is expected to begin in October 1996 (Information Circular 1996-1, page 5). Twenty to thirty per cent of the gold is recovered by gravity concentration from the Main zone ore.
Mineralization has a strong spatial relationship to both the siltstone-volcanic contact and the alteration front. The ore grade mineralization generally occurs within 50 metres of the alteration front and 150 to 300 metres from the contact with the intrusive rocks.
In 1987, Dome Mines owned the property and reported a reserve of 2.45 million tonnes at 0.34 grams per tonne Au in the Main zone (open pit), 272,000 tonnes at 8.58 grams per tonne Au in West zone (underground) and 589,000 tonnes at 6.86 grams per tonne Au in the Midwest zone (Property File Rimfire Davidson, A.J., 1987).
In 1995, with support from the Explore B.C. Program, Kinross Gold Corporation completed 2579.4 metres of diamond drilling in 8 holes. Three holes tested the east extension of the Main zone and confirmed the continuity of favourable alteration and intersected marginal gold values. Five holes tested the projected west extension of the West zone and found that this projection has been removed by erosion. A third possible extension of the orebody, farther to the northwest, remains to be tested (Explore B.C. Program 95/96 - A107).
Reserves as of January 1, 1996 are 1,287,239 tonnes grading 4.35 grams per tonne gold (T. Schroeter and R. Lane, personal
Mining at QR started April 1995 and mill startup was June 1, 1995. Mining is taking place from a small starter pit on the northwest end of the West zone, as well as from the 980 level bench of the Main zone. A temporary shutdown of all mining will take place in mid-December 1996 and last for approximately 6 to 8 weeks. During that time the mill will process stockpiled ore from the Main and West zones. Mining is scheduled to resume in January-early February 1997 from the underground developments on the Midwest zone. Later on mining will resume from the Main zone, but reserves there will be exhausted by August 1997. Approximately 170,000 tonnes will be mined from the southeast end of the West zone, also. The mineral resource in 1996 for QR is: 300,000 tonnes grading 4.3 grams per tonne gold for the Main zone; 350,000 tonnes grading 4.9 grams per tonne gold for the Midwest zone; and 550,000 tonnes grading 4.9 grams per tonne gold for the West zone. An exploration budget of at least one million dollars has been established for 1997. Areas targeted for drilling will be the basalt-siltstone contact east of the Main zone, North zone and West zone (B. Lane, personal communication, 1996).
At December 31, 1996, reserves and resources are as follows (WWW http://www.kinross.com/opps/mining/opqrare.htm):
_____________________________________________________________________Reserves/Resource Tonnes Gold (g/t) Proven ore: 525,000 4.03 Probable ore: 1,049,000 3.97 Total Proven & Probable: 1,574,000 3.99 Possible ore: 21,000 5.52 Drill Indicated Resources: 109,000 6.50 ______________________________________________________________________ |
Production at the QR gold mine, at an average milling rate of 1056 tonnes per day, totalled 1,342,240 grams of gold and 515 kilograms of silver from 382,472 tonnes of ore milled in 1996, the first full year of production. Reserves estimated by Kinross Gold Corporation at January 1, 1997 were 1,574,000 tonnes grading 3.99 grams per tonne gold. Mining of the underground Midwest zone (985 level) began at 600 tonnes per day in the fall of 1997, using longwall stoping methods. Towards the end of the year, the mill was processing 800 to 900 tonnes per day. Gold production int he third quarter was 274 kilograms, 37 per cent lower than the same period in 1996.
Lower production and increased costs were incurred because of a slope failure in the Main zone pit which temporarily halted production and decreased both millhead grades and daily throughput. Underground production from the Midwest zone carries inherently higher mining costs, and development of a new ramp to access remaining reserves in the Main zone also contributed to higher costs.
A decision to close down operations on March 1, 1998 was announced in December. Surface exploration drilling (169 holes, 24,495 metres) was carried out in several areas of the property in 1997. The drilling tested the North zone and areas between the Midwest and West zones, focusing principally on the siltstone-basalt contact within a few hundred metres of the contact with the diorite (Information Circular 1998-1, page 8). The QR mine was placed on a care and maintenance program in April 1998.
In 1998, drilling consisted of 84 holes, totalling 6318 metres. A new zone, Northwest, represents approximately 120,000 tonnes grading 3.5 grams per tonne gold (Tom Schroeter, 1998). In June 1998, Kinross merged with Amax Gold Inc. In 1999, Big Valley Resources began negotiations to purchase the QR mine. Remaining open pit and underground proven and probable reserves are 320,000 tonnes grading 5.08 grams per tonne gold (Exploration in BC 1998, page 36).
Cross Lake Minerals Ltd. reported additional possible reserves of 19,485 tonnes grading 7.41 grams per tonne gold and a resource (measured, indicated and inferred) of 463,221 tonnes grading 5.03 grams per tonne gold. These data are based on Kinross' pre-National Instrument 43-101 mine status report from January 25, 1999 (PR REL July 10, 2002). The combined reserve and resource figure is 802,584 tonnes grading 5.65 grams per tonne gold.
Cross Lake Minerals Ltd. drilled 5 holes in the West zone during 2002 and reported a 14.5-metre intersection that assayed 4.0 grams per tonne gold. Cross Lake Minerals Ltd. drilled one hole in the North zone, 13 holes in the Northwest zone and five holes in the West zone during 2002.
Cross Lake Minerals Ltd. drilled four holes into the West zone in February 2003. All four holes encountered intercepts carrying gold values including 8.5 metres in drillhole CL-03-2022 grading 11.2 grams per tonne (Press Release, Cross Lake Minerals Ltd., March 6, 2003).
Cross Lake Minerals Ltd purchased the dormant QR gold mine from Kinross Gold Corporation in April, 2004. Exploration in 2004 focused on the partly mined Midwest deposit and the North zone, a faulted extension of the mined Main zone. A seven-hole drill program totaling about 4000 metres on the Midwest deposit successfully intersected a deeper projection of the zone and yielded some encouraging assays that may lead to an expansion of the deposit.
In 2005, Cross Lake Minerals Ltd completed a feasibility study on the dormant gold mine. It also rehabilitated the underground Midwest zone as part of its re-evaluation of the property. It conducted a limited infill drilling program on the West zone, drilled two holes to further test the promising North zone and drilled another two holes to evaluate an IP chargeability anomaly. The company drilled 1,972 metres in 9 holes.
Mine permitting and approvals continued from 2005 to 2007 with production formally announced on November 28, 2007. Initial production is from the former open pit and development work is ongoing for underground operations in the North Zone.
Operations at the QR Mine have resulted in lower than expected ore production and grade, in addition to increased costs, which continue to negatively affect operations despite the completion of major repairs to the mill to sustain operations. The poor ore grade and increased costs during the winter months have made operations uneconomical. On December 22, 2008, Cross Lake Minerals Ltd. announced the decision of its board of directors to temporarily shut down operations at the QR Mine. Cross Lake expects to complete this temporary shutdown by mid-February 2009. The Company will continue to run the water treatment plant for a period of time after the shutdown to treat the water in the tailings pond.
In late 2009, International Wayside Gold Mines purchased the QR mine and mill and, in January 2010, changed their name to Barkerville Gold Mines Ltd. Early in 2010, Barkerville restarted mining operations at QR and announced the production of the first gold bar weighing 9.77 kilograms in September 2010. The company expects to produce approximately 1500 kilograms in their first year of production (Press Release September 15, 2010).
In 2012, Barkerville Gold Mines Ltd. announced that they received an amendment to their Mines Act permit for the mill at the QR mine to process the ore from the Bonanza Ledge (MINFILE 093H 140) open pit mine.
