The mining newspaper for Alaska and Canada's North
Explorer focuses on production feasibility of gold-silver project; signs pact with Seabridge Gold on adjacent Snowfield property
Pretivm Resources Inc. reported considerable exploration progress this field season at its high-grade gold Brucejack Project in northern British Columbia. The explorer Oct. 17 said it concluded exploration drilling at Brucejack for the season, with 176 holes completed totaling 72,144 meters.
Pretivm also reported in September that ongoing drilling at Brucejack continued to demonstrate continuity of high-grade gold mineralization on the property, and visible gold continues to be encountered.
Among drilling highlights:
Hole SU-230 intersected 1.0 meters with uncut grades of 7,420 grams of gold and 3,800 g/t silver (3.3 feet averaging 216.4 ounces gold and 110.8 ounces of silver per ton); and
Hole SU-226 intersected 0.5 meters with uncut grades of 1,465 grams of gold and 863 grams of silver per tonne (1.6 feet averaging 42.7 ounces gold and 25.2 ounces silver per ton).
The bonanza-grade intercept in hole SU-230 was intersected within a 6.5-meter interval with cut grades of 76.8 g/t gold and 478.5 g/t silver (uncut grades of 1,349 g/t gold and 740 g/t silver). This interval is located about 40 meters from a high-grade interval from hole SU-195 with uncut grades of 5,740 g/t gold and 2,750 g/t silver over 0.5 meters. Both holes were drilled on the eastern-most section of the Valley of the Kings Zone at Brucejack, which remains open to the east and down dip.
Pretivm Oct. 27 also reported 12 additional intersections averaging more than 100 g/t gold, including an intercept from hole SU-260 averaging 17,750 g/t gold and 7,780 g/t silver over 0.5 meters, reflecting the second-highest grade gold intersected to date on the property.
Drilling in other zones on the Brucejack property also continued to encounter high-grade gold within broader intervals of significant gold values. A highlight is hole SU-215 in the Galena Hill Zone, which intersected 55.0 meters grading 4.7 g/t gold and 47.5 g/t silver, including 0.5 meters with uncut grades of 462 g/t gold and 311 g/t silver
Pretivm also continued to define the high-grade structures in the Gossan Hill Zone. Hole SU-201 intersected 1.5 meters with an uncut grade of 168.5 g/t gold. Hole SU-207 intersected 48.5 meters grading 7.7 g/t gold, which included higher-grade intervals of 0.5 meters with an uncut grade of 350 g/t gold, and 1.5 meters with an uncut grade of 224 g/t gold.
Drilling in the Golden Marmot Zone, located 3.5 kilometers (2.2 miles) north of the Valley of the Kings zone, has identified a new high-grade structure. Hole SU-197, the first hole drilled in the Golden Marmot Zone, intersected 1.3 meters grading 23 g/t gold within a wider zone of 17.3 meters grading 2.8 g/t gold.
Pretivm began the 70,000-meter drill program it planned for 2011 in May, and encountered one of the highest-grading gold intersections to date on the property in one of the first holes drilled. Hole SU-115, drilled in the Valley of the Kings zone, intercepted 0.6 meters with uncut grades of 18,755 g/t gold and 9,312 g/t silver.
Assay results for 54 holes, including 43 from the Valley of the Kings Zone, are still pending.
2010 acquisition from Silver Standard
A newly created junior, Vancouver, B.C.-based Pretivm purchased the Snowfield and Brucejack adjoining properties, which also are adjacent to Seabridge Gold Inc.'s KSM Project for C$450 million from Silver Standard Resources in October 2010.
Brucejack is primarily a gold-silver deposit that also may contain variable amounts of base metals such as copper, lead and zinc, with a mineral resource estimate totaling containing 8.2 million ounces of measured and indicated gold resources (297.0 million metric tons grading 0.86 g/t gold and 12.17 g/t silver) and 12.6 million ounces of inferred gold resources (542.5 million metric tons grading 0.72 g/t gold and 8.67 g/t silver) at a cut-off grade of 0.30 g/t gold-equivalent.
The Snowfield deposit, however, is a near-surface, low-grade, bulk-tonnage, porphyry-style deposit containing 25.9 million ounces of measured and indicated gold resources (1,370.1 million metric tons grading 0.59 g/t gold) and 9 million ounces of inferred gold resources (833.2 million metric tons grading 0.34 g/t gold) at a cut-off grade of 0.30 g/t gold-equivalent, with additional silver, copper, molybdenum and rhenium resources.
The properties are located about 64 kilometers, or 40 miles, north of Stewart, B.C., and just east of the Alaska panhandle.
Cooperative pact with Seabridge
Pretivm, led by mining industry veteran Robert Quartermain, issued 44.2 million shares in December in an initial public offering that attracted considerable interest from investors. The company's working capital at June 30 totaled about C$35.3 million and with another C$15.08 million raised subsequent to the end of the quarter, said it expected to have sufficient working capital to fund its planned exploration programs and administrative overheads through 2012.
In May, Pretivm reported that it signed mutual cooperation and confidentiality agreements with Seabridge Gold Inc. to cooperate in advancing Pretivm's Brucejack and Snowfield projects and Seabridge's KSM project, which together represent the largest undeveloped gold resource in North America.
In addition to standard provisions, the agreements provide for the preparation of an engineering study examining the economics of combining and operating Pretivm's Snowfield project and Seabridge's KSM project as a single operation. The study is expected to be completed by year's end.
Pretivm, meanwhile, acquired additional claims to support potential project infrastructure at the Brucejack Project. The junior's claims now total more than 90,000 hectares (222,000 acres) for that property and extend as far eastward as Highway 37. Work continues on rehabilitation and extension of an access road from Brucejack to Highway 37. The road is expected to be completed in late 2012.
PEA eyes 16-year mine life
In early June, Pretivm reported a NI 43-101-compliant preliminary assessment examining the economics of an underground mining operation at Brucejack using the higher-grade gold and silver resources defined to date.
Previous operators dating back to the 1960s have conducted significant exploration at Brucejack, including 908 drill holes (as of September 2011) covering 120,000 meters and permitting for underground mine development.
The PEA contemplates an average processing rate of 1,500 metric tons per day over a 16-year mine life, an estimated capital cost, including contingencies, of US$281.7 million, and average annual production for the first 10 years of 173,200 ounces of gold and 1.12 million ounces of silver.
The base case estimated pre-tax net present value (5 percent discount) is US$662 million, with an internal rate of return of 27.1 percent, using US$1,100/oz gold and US$21/oz silver.
Using spot metals prices at the time of completion of the PEA of US$1,536.30/oz gold and US$37.89/oz silver, the estimated pre-tax NPV (5 percent discount) is US$1.416 billion with an internal rate of return of 48.3 percent.
The PEA contemplates the use of diesel power for the Brucejack high-grade project. A power line study has just been completed which examines alternatives for routing electric power into the Brucejack Project. The study covered potential interconnections to the transmission line from the Long Lake hydroelectric power project, to the existing transmission line between Meziadin and Stewart, and to the proposed Northwest Transmission Line. The results of the study will be incorporated into an update of the PEA which is to commence this quarter and is expected to be completed in the first quarter of 2012.
Winter work ahead
The junior also reported that the Brucejack camp is being expanded and winterized for year-round operations. A crew and equipment have been mobilized to begin de-watering the 5,300 meters of historic West Zone underground workings. Once the workings have been de-watered, alternatives for underground access to the Valley of the Kings Zone high-grade gold mineralization will be assessed for potential underground drilling and/or bulk sampling.
Condemnation and geotechnical drilling also has been conducted in support of a feasibility study. Two condemnation holes have been drilled at the mill site, and a drill has been mobilized to begin further condemnation drilling at the site of the Highway 37 concentrate processing facility. Geotechnical drilling has included 10 holes totaling 610 meters.
Completion of an update to the Brucejack mineral resource estimate is anticipated later in 2011. Updated corebox.net 3-D drill models for the Brucejack exploration zones, including a new drill model for the Valley of the Kings Zone are available on the company's website.
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