Candelaria, Nevada, United States
The property is located in central west Nevada just off the paved highway 95, which connects Las Vegas with Reno. The past producing minesite is serviced by paved road, power and water. Reclamation of the Candelaria Mine has been ongoing since 1998. The mine dumps were re-contoured and seeded, and the heap leach piles were rinsed with fresh water and seeded. Other infrastructure has been removed, and the substantial reclamation work meets all state and federal guidelines.
The project lies within the Candelaria Mining District, historically the richest silver mining district in Nevada. Estimated production from the late 1880’s to 1954 was 22 million ounces of silver. From 1874 to 1883, the Northern Belle Deposit alone produced high grade lodes averaging 1,700 – 2,000 g/t (50 – 60 oz/t) silver. Open pit mining between 1980 and 1999 resulted in the production of 47 million ounces of silver, with Kinross Gold producing approximately 13 million ounces of that between 1994 and 1999.
Silver Standard acquired the project in 2001 and completed technical resource report titled “Candelaria Project Technical Report” dated May 24, 2001 (filed on SEDAR on June 20, 2002), prepared by Pincock Allen & Holt. Historical resources are shown in the table below.
Silver One’s goal is to re-evaluate these resources and to explore for potential down-dip, high-grade extensions to the system. Drilling completed by Silver Standard partially delineated some of these deeper targets, but the testing of their full potential has not been completed.
Area/Type Classification Tons Factored Ag Grade (opt Agtotal) Sol. Au Grade (opt Ausoluble) AqEq Grade (opt AgEqtotal) Ag Ounces (Agtotal) Aq Equiv. Ounces (AqEqtotal) Mount Diablo Measured 3,391,000 4.44 0.004 4.67 15,054,000 15,838,000 Indicated 10,231,185 2.84 0.003 3.01 29,005,000 30,796,000 Subtot. M + Ind 13,623,000 3.23 0.003 3.42 44,060,000 46,633,000 Mount Diablo Inferred 5,191,000 2.12 0.003 2.30 11,015,000 11,939,000 Northern Belle 9,162,000 2.26 0.002 2.37 20,661,000 21,714,000 Leach Pads 37,328,000 1.29 — 1.29 48,153,000 48,153,000 L.G. Stockpiles 4,000,000 0.75 — 0.75 3,000,000 3,000,000 Subtot. Inf. 55,681,000 1.49 0.002 1.52 82,829,000 84,806,000
- Lode resources tabulated at a 0.5 opt Agsoluble cutoff grades, with only Agtotal shown in this table
- Leach pads and low grade stockpile resources tabulated for entire accumulation of material.
- Total silver grades factored from soluble silver grades using regression formulas developed by Snowden.
- Silver equivalent grade includes the contribution from the gold grade (soluble) using an Ag:Au equivalency ratio of 57.8:1.
The historical mineral resource estimate used “measured mineral resource”, “indicated mineral resource” and “inferred mineral resource”, which are categories set out in NI 43-101. Accordingly, Silver One considers these historical estimates reliable as well as relevant as it represents key targets for exploration work by Silver One. The data base for the historical resource estimate
- on the Mount Diablo Deposit consisted of 538 drill holes by previous owners and 10 drill holes by Silver Standard Resources Inc. For drill holes that were twinned, the author used the lower of the two values assigned to the original holes. The mineral resource estimate used a kriging estimation method to establish ore zones with a cut-off grade of 0.5 opt Ag. Ordinary kriging was used to interpolate grades in the block model. The block models were set up with block dimensions of 25 feet by 25 feet in plan and 10 feet in height. The maximum search range used in the higher-grade zone was 235 feet, in the lower grade zone it was 1,000 feet and in the background zone it was 350 feet. Block models more than 300 feet from the nearest composite only constituted 3 percent of the total number of estimated blocks and were assigned to an inferred category,
- on the Northern Belle Deposit consisted of 226 drill holes by previous owners, of which a portion of these holes were duplicated for the Mount Diablo Deposit database. The mineral resource estimate used a kriging estimation method to establish ore zones with a cut-off grade of 0.5 opt Ag. The mineral resource estimate used multiple indicator kriging to interpolate grades in the block model. Block models were set up with block dimensions of 50 feet by 50 feet in plan and 20 feet in height. The maximum search range used in the higher grade zone was 85 feet, in the intermediate-grade zone was 120 feet and the lower-grade zone was 140 feet and in the lower undifferentiated material below the current pit topography was 260 feet. Block models more than 300 feet from the nearest composite only constituted 3 percent of the total number of estimated blocks and were assigned to an inferred category;
- on the Leach Pads consisted of 24,633,000 tons located on Leach Pad 1 and 12,695,000 on Leach Pad 2. The estimate for Leach Pad 1 is based on the fact that silver production indicates 51.5% of total silver was recovered by heap leaching operation, while 81.2% of the soluble silver contact was recovered. Further, the estimate for Leach Pad 2 is based on the fact that silver production indicates 42.4% of total silver was recovered by heap leaching operation, while 71.3% of the soluble silver content was recovered;
- on the Low Grade Stockpile is based on limited and incomplete data and documentation. Material placed on the on the stock piles ranged from 0.5 to 0.65 opt Ag,
To the knowledge of Silver One, there is no new data available since the calculation of the above historical resource estimate and no additional work has been done to upgrade or verify the historical resource estimate. The qualified person has not done sufficient work to classify the historical estimate as a current mineral resource therefore Silver One is treating these historical estimates as relevant but not current mineral resources.
Mar 24, 2017Candelaria Technical Report