Firestone Ventures Inc. (TSX VENTURE:FV)(FRANKFURT:F5V) has announced that it has confirmed high-grade mineralization containing up to 34.3% zinc on its road-accessible Black Mountain zinc-lead-silver property located 29 km northeast of Wells, Nevada, U.S.A.
In addition to identifying on-surface high-grade zinc mineralization, field crews defined a total of seven zinc-lead-silver soil anomalies.
"We are pleased with these initial results at the Black Mountain project in Nevada – we have noted many similarities between Black Mountain and other stratabound zinc-lead-silver deposits and occurrences," says Lori Walton, President of Firestone Ventures Inc. "The price of zinc has been increasing and is now in the USD $1.00/pound ($2200/tonne) range."
Firestone recently acquired 60 mineral lode claims from Kinross Gold Corp. (see news release Nov. 29, 2010). Kinross had staked the property in 2008 for its gold potential; however, high-grade zinc mineralization was defined on surface and through Kinross' initial soil sampling program. No historical records of zinc or lead production from the Black Mountain area exist, although three mineralized areas with small tunnels and shallow pits (Juniper, Saddle and Medicine Creek workings) have been described in government reports for the area.
Firestone field crews collected 1,089 soil samples and 167 rock samples during August and September, 2010. Soil samples were collected every 50 m on east-west lines at 100 m spacing. The soil grid covered the four known areas of zinc mineralization on surface (Juniper, Saddle, Broken Pick and Medicine Creek) and identified three new areas of interest defined through soil anomalies (Willow Creek, Thurston Springs, and Brush Creek).
Saddle Workings
A grab rock sample from a dump near the Saddle workings returned 34.3% zinc, 0.77% lead and 4 ppm silver. The workings consist of four small pits and trenches and one south-trending caved tunnel. Mineralization consists of a flat-lying replacement zone, 2 to 3 m thick, with grab rock samples containing 1.5% to 18% zinc, up to 1.26% lead and up to 4 ppm silver.
Juniper Workings
A total of 28 rock samples were collected from the Juniper workings and 22 of the samples collected returned results greater than 500 ppm zinc and up to 17.8% zinc, 3150 ppm lead and 1.5 ppm silver. The workings consist of two short northeast-trending tunnels and five shallow pits and trenches. Six continuous chip samples across 12 m along the southern trench-tunnel averaged 5.2% zinc and 1% lead with true thickness about 4 m. The zone of anomalous to ore-grade zinc is exposed across an area 270 m north-south by 60 m east-west. Grid soil sampling in the Juniper workings area returned results of up to 5278 ppm zinc and up to 698 ppm lead in the soil.
Medicine Creek Workings
The Medicine Creek workings consist of a west-trending tunnel caved at the portal and four shallow trenches. Five 2-m wide chip samples collected from four of the five trenches contained 2% to 9.5% zinc. A grab sample from the dump of the caved adit contained 9% zinc, 0.2% lead and 2.5 ppm silver. The zinc mineralization exposed at Medicine Creek covers an area 75 m east-west by 50 m north-south. Soil sampling returned results of up to 7350 ppm zinc and up to 1378 ppm lead.
Broken Pick Adit
A total of 28 rock samples were collected from the Broken Pick adit. Twenty-five of the samples contained more than 1% zinc with a high of 10.4% zinc. Nine of the samples contained >1% lead with a high of 14.5% lead. Underground mapping delineated a mineralized zone 2 to 4 m thick across an east-west width of 40 m. The zinc mineralization is related to the intersection of two faults. The Broken Pick soil anomaly covers 300 m x 600 m and contains up to 2458 ppm zinc and 86 ppm lead.
New Soil Anomalies
Soil anomalies were identified over three new areas (Willow Creek, Thurston Springs and Brush Creek) in addition to the four known areas described above. The Willow Creek soil anomaly covers a 50 m x 150 m area with average soil values of 1003 ppm zinc and 283 ppm lead. The Thurston Springs soil anomaly covers an area 400 m x 200 m with zinc values up to 3254 ppm and lead up to 446 ppm, with an average of 643 ppm zinc and 86 ppm lead for all the anomalous values. The Brush Creek anomaly covers a 400 m x 100 m area with average soil values of 374 ppm zinc and 31 ppm lead. Silver content in soil was generally low (below 0.1 ppm), but did range up to 5.5 ppm.
Geology and Mineralization at Black Mountain
Black Mountain is a north-trending anticline bounded by normal faults on the east and west. Zinc-lead-silver mineralization is hosted in Devonian carbonate rocks exposed along the crest of Black Mountain. Mineralized zones are adjacent to north-trending range-front normal faults. The axis of the broad anticline trends north along the crest of Black Mountain and provides an extensional structural environment which increases permeability.
Mineralization consists of smithsonite, hemimorphite, and spotty remnant galena typically oxidized to cerrusite. Gangue minerals consist of calcite and barite plus stockwork quartz veining with up to 10% clay adjacent to normal faults. Alteration consists of varying amounts of bleaching, recrystallization, calcite veining, moderate iron oxide staining, and post-mineral silicification (jasperoid). Strong, pervasive silicification (jasperoid) is associated with northwest and northeast-trending subsidiary faults at both the Juniper and Medicine Creek workings. The structural setting, host environment, and style of mineralization at Black Mountain are very similar to the base metal ore deposits of the Irish Midlands Basin.