) (NYSE MKT:SVBL) reported Tuesday drill results from the first six holes of the underground program announced earlier this year at the eastern end of the Shallow silver zone on its Sierra Mojada project in Coahuila, Northern Mexico.
The program is designed to twin a series of holes in a high grade zone defined by a historical "long hole" data set at the eastern end of the Shallow area.
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.
Highlights of the program include 23 metres of 309 grams per tonne (g/t) silver, including 4 metres at 1,648 g/t silver, and 21 metres of 242 g/t silver, including 3.5 metres of 916 g/t silver.
Results also yielded 19.9 metres of 192 g/t silver, including 4.05 metres of 524 g/t silver, and 5 metres of 152 g/t silver.
High grade zinc intercepts included 19.2 metres of 10.42% zinc, 12.75 metres at 7.52% zinc, 13 metres at 3.83% zinc, and 14.90 metres at 2.02% zinc.
"We are extremely pleased with the first batch of results to come in from the long hole twinning program," said president and CEO Tim Barry.
"We are seeing a good correlation with the historical long hole data set and are proving that the high grade silver zone we see in the long hole data is real, and exists over wide intercepts of core.
"Proving out this high grade zone with the twinning program will be a significant step forward for this project as we are confident it will add significant ounces to the growing Shallow Silver Zone, and likely increase the overall grade of the deposit."
Silver Bull's planned 3,000 metre drill program is ongoing with 2 underground "Termite" rigs twinning a series of long holes, with up to 50 meter long diamond core drill holes.
The miner said the main target area is a high grade silver zone hosted along an east-west trending structure, with a "present traceable strike of approximately 1 kilometre."
In addition to confirming the grade and tenor of the silver mineralization with the twinning program, the company said that much of the historical long hole data set ended in "significant" mineralization, so the program will also look to extend the mineralization by drilling longer holes.
Due to the limited range of the Termite drills, and despite extending some holes by as much as 25 metres, a number of holes from this batch still ended in mineralization, Silver Bull added.
The Shallow silver zone is an oxide silver deposit, hosted along an east-west trending fracture-karst system. At a 20 g/t cutoff grade, the 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.
The mineralized body averages between 30 and 90 metres thick, up to 200 metres wide and remains open in all directions.
Sierra Mojada also contains a "zinc oxide exploration target" which sits directly below and adjacent to the Shallow silver zone at its eastern end.
The miner said the "Red" and "White" zinc zones have been identified through historical data containing 3,733 channels and 1,045 long holes over a 1.5 kilometre strike length, but has too few core drill holes to delineate a NI 43-101 compliant mineral resource.
The area is located 600 metres from a functioning railway and has been periodically mined for zinc grading more than 20% over the last 100 years, Silver Bull noted.
The flagship Sierra Mojada project is located 150 kilometres north of the city of Torreon in Coahuila, Mexico. Silver Bull also has 2 mineral licences in Gabon, Central Africa, which are prospective for gold, manganese, and iron ore.