Widespread surface gold mineralization
Past production (hard rock and placer)
Geophysics defines large targets below and along strike of known showings
The Strongbox Property is located in Tule Canyon, 55 km southwest of the town of Goldfield in Esmeralda County, Nevada. The property consists of 22 Federal Lode Claims centred on Tule Canyon and covering mineralization on the east and west sides of the canyon.
The Strongbox Property is located in the Walker Lane in an area underlain by granodiorite of the Sylvania Pluton and cut by Miocene to recent NW striking strike-slip faults and N to NE trending extensional faults. The area is distal from known Tertiary volcanic centres and has not been extensively explored in modern times.
Placer mining in Tule Canyon dates from 1848 when Mexican placer miners first began work in the area and has continued until recent times. Numerous bedrock occurrences in the walls of the canyon along the length of the creek were mined on a small scale although no hard rock production is documented in the immediate property area. On the west side of Tule Canyon, a miner named “Honest Tom” Jaggers reportedly mined his “Dark Secret Mine” from the 1890’s until perhaps the 1930’s. A recent, undocumented and more extensive underground mining operation ran on the east side of Tule Canyon (Eastside Mine) following a strong vein which was mined over a length of about 110 m to a depth of about 100 feet. A dry wash placer operation of perhaps the same vintage mined altered bedrock near the site of the Dark Secret Mine.
Gold on the Strongbox Property is widespread, following an ENE-WSW trend. The most significant showings to date have been found in Tule Canyon where there is good bedrock exposure in the canyon walls. Gold is hosted in medium crystalline quartz-limonite-clay shear-hosted veins from a few centimetres to 1.5 m wide carrying pyrite, chalcopyrite and black sooty sulphides. Major shears are spaced in the order of 10 to 20 metres apart where exposed in the cut at the Dark Secret Mine. In this area there is a coincident 400 m by 200 m alteration zone with pervasive hematite, limonite, kaolinite, illite and smectite replacing granodiorite. On the other side of the canyon at the Eastside Mine, bedrock is relatively unaltered but the mineralization is similar in character to that at the Dark Secret Mine. The vein mined at the Eastside Mine is up to 1.5 m wide and persistent on strike for over 110 m. There is a marked discordance in vein orientation between the two zones with veins and shears near the Dark Secret Mine dipping moderately east while the Eastside Mine vein dips steeply east.
At Strongbox, grab, float and chip sampling from 2016 to 2018 returned assays up to 37.1 g/t Au with 19 of 58 samples returning assays greater than 5 g/t Au. Best chip sample results include 0.7 m @ 37.1 g/t Au from a vein exposed west of the Dark Secret Mine in a canyon and from a chip 0.3 m @ 5.25 g/t Au sample across the back of a stope in the Eastside Mine. The broad alteration zone containing the vein network at the Dark Secret Mine is also mineralized; chip sampling across this zone returned 40m @ 0.469 g/t Au including 20 m @ 0.923 g/t Au.
Silver Range conducted ground total magnetic field (TMF) and horizontal loop electromagnetic (HLEM) surveys at Strongbox in 2017. The surveys identified two prominent through going resistive zones interpreted to be faults. A low frequency resistive zone was also located beneath the Dark Secret Mine and a strong 14 KHz resistive zone is nearly coincident with the East Zone. The mineralization at both mines occurs in a magnetic low, an embayment in a larger east-west feature transecting the western portion of the property. This magnetic low may be caused by magnetite destruction as the low is coincident with the large clay alteration zone containing mineralized shears at the Dark Secret Mine.
Work to date suggests gold mineralization may be controlled by a ESE-WSW trending, right lateral shear deformation zone within which NNW-N striking tensional veins and shears are mineralized. In the area of Tule Canyon, this zone overprints or interferes with a north-striking fault zone well imaged in the 14 KHz resistivity data. The Dark Secret and Eastside Mines are in this region and the dip discordance between them suggests they are hosted in a negative flower structure developed along the fault zone. Drill targets have been defined by geophysics in the area of the two small mines and the larger mineralized trend has not been explored outside of the immediate Tule Canyon area.