Vancouver-based Silver Bull Resources (TSE:SVB)(NYSE MKT:SVBL) announced Thursday results from the ninth batch of drill holes that formed part of the underground drill program at its Sierra Mojada project in northern Mexico.
The campaign was designed to twin a series of what the company calls "long holes" in a high grade silver zone found at the eastern end of the Shallow Silver Zone at the property.
The aim of the campaign is to increase confidence in the historical long hole data set, which represents 38,000 metres of drilling that was either "severely restricted" or discarded in the company's latest NI 43-101 resource report on the Shallow Silver Zone in July.
High grade silver results from the latest batch of 11 drill holes include 15.05 metres of at 463.55 grams per tonne (g/t) silver, including 3.1 metres at 1,654.92 g/t silver in hole T12090.
Hole T112080 also returned 30.5 metres at 131.34 g/t silver, including 7.6 metres at 405.78 g/t silver, and hole T12091 hit 32.55 metres at 94.10 g/t silver, including 1 metre at 546 g/t silver.
In addition, hole T12089 intersected 13.85 metres at 64.48 g/t silver, including 1 metre of 546 g/t silver.
The company said mineralization remains open in the north, south, east and west. Shares in Silver Bull were trading at 45 cents in Toronto on Thursday.
The company's 3,000 metre drill program in the high grade silver zone is ongoing, with two underground rigs. The area is hosted along a series of "stacked" east-west trending structures with a combined traceable strike of roughly 3 kilometres at the eastern end of the Shallow Silver Zone.
The twinning drill program is slated to wrap up before the end of the year, Silver Bull said, after which it will initiate a revised NI 43-101 resource update on the Shallow Silver and Zinc Zones, scheduled for release in the first quarter of 2013.
As the silver and zinc miner said in September, it has expanded the underground drill program with an additional 2,000 metres to twin a series of long holes in the high grade zinc zone, which sits just below the silver mineralization.
This twinning program started in October on the zinc body, which has a current strike length of 1.5 kilometres and an average grade of over 8% zinc. Initial drill results from the twinning program in the zinc zone are expected later this month.
In addition to confirming grades of the silver and zinc mineralization with the twinning program, the company said that much of the historical long hole data set ended in "significant mineralization", so the drilling campaign will also look to extend this by drilling longer holes.
The recent drilling, combined with historical channel sampling and underground mapping, shows at least three distinct east-west trending structures that host high grade zones of silver, the company noted.
Silver Bull further said that a halo of silver mineralization grading up to 80 g/t exists in between the high grade zones and provides the tonnage for a potential "bulk minable" deposit in an open pit setting.
At a 20g/t cutoff grade, the Shallow Silver Zone has a measured resource of 3.023 million tonnes at an average grade of 65 g/t for 6.343 million contained troy ounces of silver, an indicated resource of 38.560 million tonnes at an average grade of 50 g/t for 61.694 million contained troy ounces of silver, and an inferred resource of 6.491 million tonnes at an average grade of 45 g/t for 9.478 million contained troy ounces of silver.
Silver Bull's main Sierra Mojada project is located 150 kilometres north of the city of Torreon in Coahuila, Mexico, while the company also has 2 mineral licenses in Gabon, Central Africa, which are prospective for gold, manganese, and iron ore.
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