Information with respect to estimated resources is set forth below.
(as of December 31, 2010)
Hecla's 70% |
Tons |
Silver (oz/ton) |
Gold (oz/ton) |
Zinc (%) |
Lead (%) |
Silver (oz) |
Gold (oz) |
Zinc (tons) |
Lead (tons) |
||
| Estimated Resources (1) |
2,165,000 |
12.0 |
– |
1.3 |
1.7 |
25,946,000 |
– |
28,600 |
36,200 |
(1) Inferred resources, diluted and factored to minimum mining width. San Juan JV (Creede, CO) reportable @ 70% to Hecla.
The United States Securities and Exchange Commission permits mining companies, in their filings with the SEC, to disclose only those mineral deposits that a company can economically and legally extract or produce. We use certain terms on this website, such as "resource," "other resources," and "mineralized materials" that the SEC guidelines strictly prohibit us from including in our filing with the SEC. U.S. investors are urged to consider closely the disclosure in our Form 10-K, included on this website.
overview
In December 2011, Hecla's wholly owned subsidiary, Rio Grande Silver, Inc., (RGS) acquired the remaining 30% joint venture interest from its partners in approximately 55% of the 21-square-mile consolidated land package in the famous Creede Mining District, one of Colorado’s most prolific silver-producing districts (see Figure). The whole-owned property encompassed the entire Bulldog, Amethyst and Equity veins including a resource of approximately 37 million ounces, with potential for considerably more through a targeted exploration program. In addition, the Company maintains a 70% interest in an exploration joint venture that will cover the remaining land package that contains the less explored targets and is on the east and west flanks of the RGS property.
San Juan Silver received approval of its Environmental Assessment and 5-Year Plan of Operation in mid-2010, enabling aggressive expansion of exploration on three vein systems: Bulldog, Amethyst and Equity. In October RGS received a Categorical Exclusion to the POO allowing the development of a new portal and decline at the Bulldog mine.
geology
The Creede District is located in the San Juan Mountains of Colorado, a major Tertiary volcanic field of andesitic to rhyolitic flows, tuffs and breccias which were generated by the collapse of some 18 major calderas identified in the area. In the Creede Mining District, polymetallic veins (and disseminated style deposits) are hosted by inter-caldera graben related structures associated with the Creede and Bachelor calderas. Nearly all historic production within the Creede Mining District came within the Campbell Mountain Formation rhyolitic tuffs and flows.
The property consists of a complex series of vein systems, dominated by the parallel north-south trending Bulldog and Amethyst veins with strike lengths of over seven miles which provided the bulk of historic production. Numerous north-west trending cross structures link these two veins, and several other north-south structures, including the Alpha Corsair system to the west, and the Deer Horn, and Holy Moses-Solomon systems to the east occur on the property. To the north and located in the northern portion of the land package, the east-west trending Equity vein strikes at least two miles and appears to be a structurally distinct and unique vein system. The Equity structure, unlike the dominant north-south structural and mineral trends, is an east-west reverse fault (dipping north; up to the north) that occurs at the boundary of the Bachelor caldera to the south and the San Luis caldera to the north.
Mineralization in the Creede District is hosted by fissure-fill veins, stockworks, and breccias associated with regional faulting which forms the Creede Graben. Veins are comprised of quartz, barite, pyrite, rhodochrosite and chlorite, with occasional fluorite and adularia. Ore minerals consist of pyrite, sphalerite, galena and chalcopyrite, plus variable silver sulfosalts (tetrahedrite, pyrargyrite, polybasite). Creede-type veins are typically silver rich, and although much of the spectacular ore was related to native silver, tetrahedrite is the most important silver mineral in the district. Recent drilling at the intersection of the Amethyst and Equity structures show that gold is a significant component of the mineralization higher in the mineralized system.
Given the scope of the prospective structures within the 21-square mile consolidated land package, an extensive and systematic exploration approach is required to test, identify, and confirm the potential for economic mineralization within the major structural trends of the district.
exploration
The exploration program at San Juan Silver was accelerated upon receipt of the 5-Year Plan of Operations in mid-2010, enabling expansion of exploration on three vein systems: Bulldog, Amethyst and Equity. Hecla discovered multiple zones of gold / silver-bearing veins and breccias with ore grades at the intersection of the Amethyst and Equity veins.
The most impressive vein intersections in 2010 occurred where the north-trending Amethyst vein intersects the east-west trending Equity structure. These vein intersections show multi-pulse mineralization that is both precious and base-metal rich within a 300-foot wide hydrothermal breccia zone. Holes were drilled along the western extension of the Equity structure collared west of its intersection with the Amethyst vein. This drilling intersected breccias and veins, as well as extensive silica-pyrite alteration with superimposed rhodonite and rhodochrosite-base metal sulfide-quartz mineralization.
Two drills have been operating on surface since May 2011 and have focused on extending mineralization along the Bulldog, Amethyst, and Equity veins. A drill hole targeting the northern trend of the “A Vein,” on the Bulldog vein system intersected a vein over 14.8 feet that graded 6.3 ounces per ton silver, 0.5% lead, and 2.9% zinc. A series of drill holes on a recently defined strand of the Amethyst vein has confirmed widths of the veins ranging from 5 to 17-foot wide with a strike length of 3,000 feet. At the Equity structure, the first hole intersected an 11-foot mineralized breccia within strong epithermal vein alterations. Assays on the Amethyst and Equity drilling programs are pending.
Significant high-grade intercepts from the intersection of the Amethyst and Equity veins are shown in the latest assay table to the right. These highly anomalous gold and silver concentrations encountered in the veins are very significant as it is the deepest intercept of a major vein structure to date in the northern part of the district. These intersections are well below the historically perceived bottom of the precious metal horizon in the northern part of the Creede District and may indicate a large vertical dimension (over 1,500 feet) for gold-bearing mineralization. This mineralization is also open along strike and may extend for a significant distance.
Drilling targeted the Amethyst vein structure 2,500 feet north of its historic underground workings and encountered both west and east vein strands. The West Strand of the Amethyst is the best developed and contains most of the higher grades. The East Strand of the Amethyst vein is also prospective, and is comprised of quartz healed silica breccia with pyrite-chalcopyrite-specularite cut by late stage carbonates with highly anomalous gold and silver values.
Drilling along the Amethyst intersected a multistage quartz vein for which the latest intersections are included in the latest assay table to the right.
The 2011 exploration budget for the San Juan Silver project is approximately $7 million and includes drilling of at least three structures, with particular emphasis on the newly defined high-grade mineralization at the intersection of the Amethyst and Equity.
future upside
The San Juan Silver project is the first entity to control the bulk of the famous Creede District in Colorado which has historic production of 84 million ounces of silver. Drilling and underground sampling along the past-producing Bulldog has defined at least 40 million ounces of silver and continues to intersect ore grade mineralization to the north along a one-mile trend. Where the Amethyst vein intersects the Equity structure, drilling has intersected a broad zone with multistage veins and breccias with zones of sulfides containing gold, silver, and base metals. High-grade gold and silver intersected in the veins are very significant as this is the deepest precious metal intercept of a major vein structure to date in the northern part of the district. These intersections are well below the historically perceived bottom of the precious metal horizon in the Creede District indicating a large vertical dimension of 2,000 feet, for gold-bearing mineralization. The mineralization is also open along strike and may extend for a significant distance along the Amethyst and the Equity structures. In addition, newly defined areas to the west of the Equity vein system encompass a broad gold-enriched surface anomaly cut by strong veining which will be followed up with more detailed exploration during 2011.
(Q4 2010)
| Area |
Width (Feet) |
Silver (oz/ton) |
Gold (oz/ton) |
Zinc (%) |
Lead (%) |
||
| Bulldog Amethyst - Equity Amethyst - Equity Amethyst - Equity Amethyst - Equity Amethyst - Equity Amethyst - Equity Amethyst - Equity |
13.9 7.0 2.5 2.0 2.5 2.5 2.0 5.5 |
10.82 13.05 0.77 4.93 31.83 31.83 0.32 10 |
0 0.18 0.18 0.02 0.31 0.31 0.44 0.14 |
2.0 0.5 0.7 0.3 0.4 0.4 2.8 1.6 |
7.1 1.6 0.8 0.6 3.3 3.3 1.7 0.5 |