Greens Creek | exploration
At the Greens Creek mine in Alaska, approximately 94,559 feet of underground in-fill (definition) and exploration drilling and 27,398 feet on surface was completed through 2011. The drilling tested the trends of known zones including the Gallagher, 5250 South, 200 South and the NWW resulting in a replacement of tons mined during 2011. In 2011, underground drilling in the Gallagher zone delineated several higher-grade resources within a thicker mineralized body. In the 200 South zone, drilling continues to outline a precious metal-enriched body that added 35,000 tons of new reserves and in the NWW zone, in-fill drilling converted 100,000 tons of resources to reserves. Definition of new reserves and resources in the last ten years has been able to replace mineral during that period.
The Greens Creek exploration program should exceed $7 million in 2012 with drilling planned at the Gallagher, 200 South, West Wall, NWW and 5250 zones. Two drills are expected to work underground all year, and the surface exploration program has three drills and a number of surface mapping and sampling crews in the spring and summer. Exploration along the NE contact will use underground and surface drills.
The drilling designed to test the down plunge extent of the main Gallagher mineralization to the west and south has defined a broad zone of mineralization over approximately 200 feet of strike and 400 feet down dip containing narrower 2.3 to 7.4 feet high-grade precious and base metal intervals. Drilling in the 200 South has defined two separate mineralized limbs that are typically barite-rich and contain higher values of precious metals relative to other zones in the mine. Definition drilling covered a strike length of 250 feet and added 35,000 tons of new reserve at 0.55 ounces per ton gold, 59.5 ounces per ton silver, 12.4% lead and 26.73% zinc. Exploration drilling outlined the mineralized fold another 450 feet to the south of the resource but drilling is too wide-spaced to define a resource.
Hecla continues to be encouraged with the North East (“NE”) contact, a relatively new target area that is located below the mine infrastructure. Surface and underground drilling continue to define the NE contact which represents a continuation of the Greens Creek mine contact. The contact has been folded underneath the current mine workings; it extends near surface at Cub Creek, north of the current mine infrastructure, and dips below and sub-parallel to the current mine infrastructure.
On surface at Greens Creek, two holes at West Bruin, two miles NNW of the mine infrastructure, intersected 5 to 14 foot-wide zones that encompass chalcopyrite and sphalerite-bearing vein mineralization. Final results from West Bruin showed nearby mine contacts with anomalous silver and zinc and elevated gold values. Similar chalcopyrite-bearing mineralization was intersected at Cub #4, just over one mile north of the mine. Assay results from the Cub #5 show up to 2% copper and1.5 ounces per ton silver with highly anomalous lead and zinc in pyritic muds at the mine contact. Drill holes targeting the south end of the East Ore trend intersected weakly mineralized argillite near the mine contact in for over 300 feet along strike. All three targets are likely to continue to be drilled in the summer of 2012.
Some of the high priority underground and surface targets where upside potential exists include:
- Further extension of the high-grade, precious metal-rich 200 South and 5250 zones, and further definition of two new and distinct limbs below the current workings on the NWW zones which will be added to the reserves and resources;
- Gallagher zone to the southwest is open in three directions and will be one of the primary underground exploration areas in 2012;
- Surface and underground drilling continues to define the NE contact which represents a continuation of the Greens Creek mine contact. The contact has been folded underneath the existing mine workings, extends near surface at Cub Creek less than a mile northeast of the mine infrastructure, and dips below and is sub-parallel to the mine infrastructure. Recent wide-spaced drilling has defined discontinuous mineralized intervals along the contact which has a folded strike length of over 5,000 feet and down dip extension of 3,000 feet. The NE contact’s dimension compares to the current Greens Creek deposit; and
- To the north of the mine area, surface exposures of mineralized mine contact at Cub, West Bruin Killer Creek and West Gallagher will be evaluated by surface drilling over the next year.
latest assay table results – Lower SW
(Q2 2011)
| Area |
Width (Feet) |
Silver (oz/ton) |
Gold (oz/ton) |
Zinc (%) |
Lead (%) |
||
| Lower SW Lower SW |
5.00 1.00 |
38.50 24.35 |
0.095 0.710 |
4.66 17.56 |
2.65 8.26 |
latest assay table results – Gallagher
(Q4 2011)
| Area |
Width (Feet) |
Silver (oz/ton) |
Gold (oz/ton) |
Zinc (%) |
Lead (%) |
||
Gallagher Gallagher Gallagher |
3.6 3.1 5.0 2.2 9.5 4.5 5.2 4.4 9.5 2.3 3.3 6.4 |
29.1 15.1 18.1 10.5 9.2 9.8 18.3 13.8 9.2 13.2 10.2 18.5 |
0.22 0.26 0.21 0.19 0.23 0.31 0.26 0.21 0.23 0.25 0.24 0.21 |
10.9 5.2 17.8 8.1 5.8 11.2 12.4 17.8 5.8 2.8 6.8 4.1 |
4.9 4.3 6.9 3.7 2.8 3.2 5.1 6.9 2.8 2.8 5.2 1.7 |
(Q3 2011)
| Area |
Width (Feet) |
Silver (oz/ton) |
Gold (oz/ton) |
Zinc (%) |
Lead (%) |
||
| Gallagher Gallagher Gallagher Gallagher Gallagher Gallagher Gallagher Gallagher Gallagher Gallagher |
6.60 2.60 6.40 26.30 2.70 6.60 2.70 2.30 5.30 7.40 |
13.42 3.36 5.76 5.59 6.54 14.26 8.53 6.55 8.28 8.86 |
0.230 0.300 0.160 0.100 0.041 0.302 0.080 0.120 0.080 0.285 |
15.83 16.78 8.90 6.38 17.62 6.85 12.22 5.31 2.95 8.83 |
4.12 8.22 3.71 2.97 3.70 2.96 5.96 2.23 1.38 4.47 |
(Q2 2011)
| Area |
Width (Feet) |
Silver (oz/ton) |
Gold (oz/ton) |
Zinc (%) |
Lead (%) |
||
| Gallagher Gallagher Gallagher Gallagher Gallagher Gallagher Gallagher Gallagher Gallagher Gallagher Gallagher Gallagher Gallagher Gallagher Gallagher Gallagher Gallagher Gallagher Gallagher Gallagher Gallagher |
23.80 8.90 3.00 12.00 3.70 3.40 23.90 7.80 19.10 37.40 15.00 6.40 5.50 0.90 24.00 5.00 8.00 15.30 1.60 6.50 5.20 |
4.10 5.39 10.15 5.48 6.81 1.79 5.07 2.84 3.33 4.86 2.27 4.40 3.45 33.35 2.77 13.95 4.36 16.56 2.59 23.15 5.96 |
0.077 0.055 0.049 0.041 0.060 0.027 0.066 0.033 0.055 0.067 0.037 0.071 0.034 0.120 0.043 0.190 0.212 0.291 0.017 0.065 0.045 |
8.02 0.82 3.16 8.81 9.87 0.23 6.20 1.11 3.96 4.83 1.28 1.69 8.46 5.19 1.53 6.67 1.09 7.75 9.48 6.58 1.99 |
3.80 0.53 2.00 3.70 4.93 0.34 3.08 0.74 2.06 2.47 0.54 0.86 3.88 2.28 0.71 3.33 0.66 3.45 3.88 2.71 0.86 |
latest assay table results – NWW zone
(Q1 2011)
| Area |
Width (Feet) |
Silver (oz/ton) |
Gold (oz/ton) |
Zinc (%) |
Lead (%) |
||
| West Limb West Limb West Limb West Limb East Limb East Limb East Limb |
8.7 6.6 3.3 5.0 5.0 5.1 7.1 |
32.0 149.4 25.5 12.4 9.5 6.1 10.2 |
0.12 0.87 0.57 0.11 0.20 0.10 0.21 |
15.4 4.8 21.2 15.6 22.3 20.8 18.1 |
8.9 1.1 13.0 11.5 6.4 11.8 6.7 |
latest assay table results – 200 South zone
(Q1 2012)
| Area |
Width (Feet) |
Silver (oz/ton) |
Gold (oz/ton) |
Zinc (%) |
Lead (%) |
||
| 16.8 9.9 |
32.0 17.9 |
0.02 0.05 |
8.1 7.6 |
4.0 3.7 |
(Q4 2011)
| Area |
Width (Feet) |
Silver (oz/ton) |
Gold (oz/ton) |
Zinc (%) |
Lead (%) |
||
| Upper Limb Upper Limb Lower Limb Lower Limb |
12.0 9.4 25.6 14.8 |
10.2 18.5 16.0 16.3 |
0.14 0.21 0.05 0.24 |
3.8 4.1 8.9 4.8 |
2.2 1.7 4.6 1.8 |
(Q1 2011)
| Area |
Width (Feet) |
Silver (oz/ton) |
Gold (oz/ton) |
Zinc (%) |
Lead (%) |
||
| Upper Limb Upper Limb Upper Limb Lower Limb Lower Limb Lower Limb Lower Limb |
12.5 9.2 3.1 9.9 3.9 3.5 8.5 |
24.7 23.4 26.2 30.1 23.0 172.7 21.3 |
0.48 0.17 0.06 0.18 0.06 0.07 0.17 |
4.3 3.6 3.8 2.0 5.2 7.1 5.2 |
8.4 10.6 10.1 4.4 9.5 16.3 7.1 |
latest assay table results – 9a zone
(Q1 2012)
| Area |
Width (Feet) |
Silver (oz/ton) |
Gold (oz/ton) |
Zinc (%) |
Lead (%) |
||
16.8 10.0 8.7 19.8 21.2 8.9 22.9 6.0 3.2
|
32.0 15.3 20.7 26.1 9.7 18.0 11.6 16.5 46.6 |
0.02 0.02 0.02 0.02 0.04 0.02 0.07 0.04 0.52 |
8.1 1.3 18.2 11.5 33.4 8.2 5.9 12.9 9.3 |
4.0 0.4 8.7 6.6 10.9 4.8 3.5 2.8 2.4 |