El Tigre Historic Mine District

The El Tigre historic mine district is located in Sonora, Mexico and lies at the northern end of the Sierra Madre silver and gold belt which hosts many epithermal silver and gold deposits, including Dolores, Santa Elena and Las Chispas at the northern end.  In 1896, gold was first discovered on the property in the Gold Hill area and mining started with the Brown Shaft in 1903.  The focus soon changed to mining high-grade silver veins in the area with much of the production coming from the El Tigre vein.  Underground mining on the El Tigre vein extended 1,450 meters along strike and was mined on 14 levels to a depth of 450 meters.   By the time the mine closed in 1938, it is reported to have produced a total of 353,000 ounces of gold and 67.4 million ounces of silver from 1.87 million tons (Craig, 2012).  The average grade mined during this period was over 2 kilograms silver equivalent per ton.

Silver Tiger’s district scale El Tigre concessions are approximately 35 kilometers long and comprises 28,414 hectares, including 25 kilometers of the prolific Sierra Madre trend. The El Tigre silver and gold deposit is related to a series of high-grade epithermal veins controlled by a north-south trending structure cutting across the andesitic and rhyolitic tuffs of the Sierra Madre Volcanic Complex within a broad silver and gold mineralized prophylitic alternation zone called the El Tigre Formation which can be up to 150 meters wide. The veins dip steeply to the west and are typically 1 meter wide but locally can be up to 5 meters in width. The veins, structures and mineralized zones outcrop on surface and have been traced for 5.3 kilometers along strike in our browfields exploration area.  Historical mining and exploration activities focused on a 1.5 kilometer portion of the southern end of the deposits, principally on the El Tigre, Seitz Kelly and Sooy veins. The unexplored Caleigh, Fundadora and Protectora exposed veins continue north for more than 3 kilometers and are the target of Silver Tiger’s current exploration.

El Tigre Resource Estimate

After acquiring El Tigre, Silver Tiger drilled 12,500 meters to define the halo of near surface gold mineralization around the mined high-grade veins of the historic El Tigre Mine. This allowed Silver Tiger to deliver a maiden resource estimate for the El Tigre Property to a depth of 150 meters containing indicated resources of 661,000 gold equivalent ounces at 0.77 g/t (21 g/t silver and 0.51 g/t gold) and inferred resources of 341,000 gold equivalent ounces at 1.59 g/t (88 g/t silver and 0.52 g/t gold). The complete National Instrument 43-101 technical report is available on the company’s website below under Mineral Resource Estimate and Technical Report and on SEDAR under the company’s profile.

Silver Tiger Drilling in the Northern Vein Extensions

Silver Tiger’s limited drilling in these vein extensions located north of the historic El Tigre Mine intersected similar-style silver-gold mineralization in the El Tigre formation including a new discovery in the Caleigh Vein. Drill hole ET-17-144 returned 0.85 meters of the Caleigh Vein grading 10,128.9 g/t silver equivalent consisting of 7,338.9 g/t silver, 37.2 g/t gold. The silver equivalent ratio is based on a silver to gold price ratio of 75:1 (Ag:Au).  Drill hole 144 was a step-out hole located approximately 1.7 kilometers to the north of the historic El Tigre Mine.  The mineralized zone consists of several vuggy quartz veins and veinlets carrying galena, sphalerite, chalcopyrite, stromeyerite and pyrite within a strongly silicified and kaolinized alteration zone. As well, drill holes ET-17-145 and ET-17-148, which were drilled by Silver Tiger in its previous drill program, intersected similar-style silver-gold mineralization. The significant intercepts from these three drill holes are included in the following table.

Hole ID Comment From
ET-17-144   88.25 91.40 3.15 10.1 1,990.9 2,748.4
  including 88.25 89.10 0.85 37.2 7,338.9 10,128.9
  and 188.65 190.15 1.50 0.024 1,107.3 1,109.1
ET-17-145   28.50 29.25 0.75 10.9 2,830.4 3,647.9
ET-17-148   90.10 90.60 0.50 9.83 2,247.1 2,984.35


  • 1. Not true width.
  • 2. Gold Equivalent (“EqAu75”) ratio based on silver to gold price ratio of 75:1 (Au:Ag).

The Silver Tiger exploration team are currently diamond drilling 20,000 meters of HQ core with three drill rigs targeting the 3 kilometers of vein extensions north of the historic El Tigre Mine. The drilling program is focused on the Caleigh, the Protectora and the Fundadora veins, all of which outcrop on surface and are exposed in exploration drifts in the three kilometers north of the historic El Tigre Mine,