Recent drill results from the San Nicolas discovery in Mexico’s Zacatecas state have expanded the massive sulphide deposit. The body appears to be closing off to the northeast and northwest, but remains open to the south.
Teck (TEK-T) and partner Western Copper Holdings (WTC-T) are continuing to delineate the San Nicolas body on 100-metre stepouts and have begun infill drilling on 50-metre centres for engineering purposes.
San Nicolas occurs on the western portion of the El Salvador project, a 55-45 joint venture between Teck and Western Copper. Luismin, a Mexican mining company, can back-in to a 25% participating interest in San Nicolas by arranging its share of production financing or can dilute to a 15% interest.
Teck has the right to increase its interest in the joint-venture by 10% if it chooses to arrange production financing, and can buy a further 5% from Western Copper based on the project’s net present value at feasibility, using a 15% discount.
Drilling to date has determined that massive sulphide mineralization extends over an area greater than 800 metres in a northwest-southeast direction and 400 metres in a northeast-southwest direction. The system generally consists of a higher-grade, zinc-dominant polymetallic zone at the top and a copper-rich section at the bottom, with a largely low-grade pyrite section between.
Assay results from the latest 11 holes were recently announced, bringing the number of holes completed to date to 32.
Hole SAL-56, the most northwesterly hole drilled to date, appears to define the limits of the massive sulphide body in this direction, as it did not intersect any significant mineralization. Stepping out 100 metres to the south-southwest, hole SAL-54 intersected 6 metres grading 14.3% zinc, 2.07% copper, 2.04 grams gold and 184.8 grams silver per tonne, starting at a depth of 242.3 metres.
Hole SAL-58 was collared 100 metres east-southeast of hole 56. It cut a 5-metre-thick interval grading 3.83% zinc, 0.49% copper, 1.13 grams gold and 59.4 grams silver at a depth of 265.1 metres. Hole SAL-53A, a stepout 100 metres to the south-southeast of SAL-58, cut 58.8 metres averaging 5.86% zinc, 0.72% copper, 1.47 grams gold and 81.8 grams silver, starting at 277.1 metres.
Hole SAL-46 was drilled 100 metres east-southeast of hole 53 along the northern edge of the deposit; it intersected a previously reported 18.6 metres averaging 0.88% zinc, 0.71% copper, 0.34 gram gold and 16.8 grams silver, starting at a depth 267 metres. Stepping out a further 100 metres to the east-southeast, hole SAL-48 pulled a 3.4-metre interval grading 3.06% copper, 0.08% zinc and 5.15 grams silver at a depth of 269 metres.
Stepping out another 100 metres to the east-southeast, hole SAL-50 intersected 34.1 metres averaging 2.42% copper, 0.14% zinc, 0.03 gram gold and 5.7 grams silver, beginning at a 227.1-metre depth.
Hole SAL-52, a 100-metre stepout east-southeast of hole 50, and the most northeasterly hole drilled to date, failed to intersect any significant mineralization.
Hole SAL-55 was drilled on the southern limits of the deposit, 100 metres east-southeast of previously reported hole 24 and 100 metres south-southwest of hole 35. Hole 55 intersected five significant intervals of mineralization: 19.1 metres averaging 4.51% zinc, 0.79% copper, 0.84 gram gold and 73 grams silver, starting at a depth of 270.1 metres; 27.7 metres averaging 2.83% copper, 0.04% zinc and 6.5 grams silver at a depth 318.8 metres; 7.3 metres grading 3.87% zinc, 0.47% copper, 0.86 gram gold and 39.4 grams silver at a 380-metre depth; 4.2 metres grading 2% copper, 0.35% zinc, 0.1 gram gold and 10.2 grams silver starting at a depth of 388.3 metres; and a 2.8-metre-thick interval grading 4.53% zinc, 1% copper, 4.25 grams gold and 242 grams silver at a depth of 474.6 metres.
Stepping out 100 metres east-southeast of hole 55, hole SAL-51 hit a 43.9-metre interval averaging 0.43% zinc, 2.39% copper, 0.08 gram gold and 13.3 grams silver, beginning at a depth of 292.4 metres.
Hole SAL-57 intersected a 38-metre-thick section in the southeastern end of the deposit averaging 2.38% zinc, 1.22% copper, 1.24 grams gold and 33.5 grams silver, starting at a 232-metre depth. The hole is a 100-metre stepout to the east-southeast of previously reported hole 43 and 100 metres east-northeast of hole 45.
Teck was expected to announce a resource estimate for the San Nicolas deposit, as well as initial metallurgical results, at its annual shareholder meeting originally scheduled for the end of April. However, the meeting has been postponed until June 3.
Teck is evaluating both open-pit and underground mining scenarios. Chris Bradbrook, a Toronto-based mining analyst with Yorkton Securities, has calculated a preliminary estimate of the massive sulphide body in excess of 95 million tonnes averaging 1.99% zinc, 1.29% copper, 0.44 gram gold and 26.09 grams silver, representing a gross value of US$55 per tonne. Glenn Brown, a mining analyst with Canaccord Capital, estimates the sulphide resource at approximately 100 million tonnes.
Bradbrook further estimates the higher-grade, zinc-rich polymetallic zone could contain as much as 25 million tonnes grading 5.54% zinc, 1.17% copper, 1.13 grams gold and 65.22 grams silver, with a gross value of approximately US$107 per tonne.
Teck and Western Copper have started to test two other prospective targets to the south and east of San Nicolas that have been recently defined by induced-polarization and gravity surveys.
In addition, Western Copper has begun a 3,000-metre drill program on its 100%-held, 3,255-ha Penasquito project, 200 km northeast of the city of Zacatecas in the Concepcion del Oro district. Rio Tinto (RTP-N) subsidiary Kennecott retains a back-in right to a 51% interest.
Since beginning exploration in 1992, Kennecott has carried out geochemical and geophysical surveys, and drilled 71 holes totalling 23,495 metres. This work has identified the Chili Colorado polymetallic zone, as well as two large breccia pipes and several outlying targets that have returned high-grade intercepts.
The mineralized system at Penasquito extends over an area greater than 9 sq.
km and lies beneath 30 metres of alluvial cover. Five holes in the Chili Colorado zone intersected polymetallic mineralization within an area of 600 by 150 by 100 metres, starting at a depth of 170 metres. The five holes averaged an uncut 1.43% zinc, 1.17% lead, 0.43 gram gold and 80 grams silver.
The two breccia pipes at Penasquito have been tested by a total of 35 holes to date. The Outcrop pipe has returned selected values of 6.8% zinc, 7.4% lead, 4.02 grams gold and 885 grams silver over 10.4 metres, beginning at a depth of 333 metres, as well as 170 metres averaging 2.13% zinc, 0.87% lead, 0.2 gram gold and 60 grams silver, starting at a depth of 463 metres.
The Azul pipe is highlighted by 295 metres averaging 1.1% zinc, 0.87% lead, 0.38 gram gold and 66 grams silver, beginning at a depth of 142 metres.
The objective of Western Copper’s drilling is to evaluate the extent of the previously defined zones and to test several potential geophysical anomalies.
Be the first to comment on "Drilling expands San Nicolas"