Summary

The Tybo and Keystone projects have a wide variety of target types. Complexly folded and thrusted Paleozoic sedimentary rocks were intruded by Tertiary hypabyssal intermediate to felsic dikes, sills, and stocks. Targets include poly metallic skarn, carbonate replacement, breccia hosted, and distal disseminated precious metal deposits. The Tybo district shares many characteristics of the once highly productive Eureka district, from mineralization styles to correlative rock formations. Unlike the Eureka district, however, the Tybo district remains relatively unexplored.

Location

The Tybo and Keystone properties lie in the Hot Creek Range, Nye County, Nevada approximately 120 kilometers northeast of Tonopah, Nevada.

Land Status

The Tybo Keystone property consists of 323 claims. All claims are 100% Newmont owned and located on BLM administered lands except for small portions in Tybo and Keystone canyons where minor overlap on patented claims occurs.

History

Silver ore was first discovered at Tybo in 1869. The Tybo Consolidated Mining Co. began mining the oxidized “shattered porphyry” ore, mostly from the 2G Fault/lode, in 1872. Production was continuous until 1879, when at the 122m level of the underground workings the oxidized ore ran out and changed to primary sulfide ore. The sulfide ore could not be processed, and in 1879 the company failed. Mining continued intermittently into the 1930’s under different owners. Total reported production from Tybo is approximately 5 million ounces of silver and 20,000 ounces of gold. Ferguson (1933) reported average grades produced in the 1870’s of 943g/t silver, 8.23g/t gold, and 11% lead per ton. During the 1870’s boom at Tybo, discoveries of silver ore were also made at Keystone. Although there are no published production records from Keystone, it is rumored that 1 million plus ounces of silver were produced from the New Philadelphia claim and that the poly metallic ore was shipped to Wales, Europe for processing. Also in the 1970’s, mining of a small open pit (Wiswall Pit) next to a historic shaft, exposed silver, lead, zinc, and copper (and locally gold) rich skarn deposit.

Newmont first staked claims at Keystone in 2011 and continued to add claims to the south until the last were staked around the patented claims at Tybo in 2014. Newmont has conducted five small RC scout drilling programs since 2011, three in the Keystone area and two in the Tybo area. The best silver intercept came from Tybo in 2015. Hole NTY-10 intercepted 97.5m of 39.8g/t Ag (including 3.0 m of 326g/t Ag, 2.23% Pb, 0.22% Zn). The same hole also intercepted 6.1m of 91.2g/t Ag, 3.14% Mn, 0.12% Pb and 0.25% Zn (including 4.6m of 11.6g/t Au) near the bottom of the hole.

Newmont currently has three active NOI’s; one at Keystone and two in the Tybo area. There is approximately 0.77ha of disturbance remaining at Keystone and 2.3 combined ha remaining on the two NOI’s at Tybo.

Geology

The Keystone Project is centered on a large circular feature, evidenced by mapped geology and aeromagnetics, which is inferred to be a concealed magmatic center or cupola of a large porphyry system. Mineralization within old mines and prospects in the Keystone area suggest high level porphyry style breccias, skarn, and sulfide replacement bodies with outward zoning of base metal rich mineralization to more distal disseminated gold and silver rich mineralization. The geology and mineralization at Tybo is similar to that at Keystone but sits a few kilometers south of the large inferred magmatic center. Historic mining was concentrated along high-angle, dike filled structures. Old reports refer to the high-grade Ag+Au+Pb+Zn ore host as “shattered porphyry” and locally as “carbonate chimneys”. Recent geophysical interpretations combined with drill data indicate that large low-angle, intrusive-filled structures at depth may have been the primary mineralizing structures, and the potential for large, flat-lying carbonate replacement and skarn mineralization is high.

Databases

Newmont has generated an extensive database for the Tybo-Keystone project. Newmont has drilled 48 RC holes for a total of 11,485 meters with gold assays and multi-element composite geochemical analyses. Project geophysics includes a 105 square kilometer helicopter magnetic, 60 square kilometers gravity and 7.5 square kilometers of Time Domain EM surveys. Gold and multi-element geochemical analyses are available for approximately 3,100 surface samples across the project. All are available digitally.

The north side of Tybo Canyon looking northwest towards NTY-9 & NTY-10 drill site (upper road) and pale orange Uncle Sam intrusive (left). An old manganese mine is visible in upper right. Also, a small unnamed intrusive dike or sill can be seen in the lower right foreground.