Cerro Negro Gold Project
Eureka Vein
The Eureka West Veins are on the western end of the Company’s 100% owned Cerro Negro project (approximately 250 square kilometres in size) in Santa Cruz province, southern Argentina Based on all the infill and exploration drilling completed at Eureka during the first quarter 2008, through drill-hole ERC-812, Andean released an updated JORC and NI 43-101 compliant resource estimate for the Eureka West Veins on April 16th, which included the following highlights:
- Infill drilling confirmed continuity of the high gold and silver grades
- Gold and silver grades more than doubled from the previous October 2007 resource estimate
- Total mineral resource tonnage up 15% from the prior estimate
- Contained ounces of gold increased by 119% to more than 1 million ounces of gold and 18 million ounces of silver; with grades of 12.9 g/t gold and 235 g/t silver in the Indicated category together with 0.34 million ounces of gold and 4.9 million ounces of silver (at a grade of 10.7 g/t gold and 157 g/t silver) in the Inferred category.
| Category | Tonnes | Au g/t | Contained Oz | Ag g/t | Contained Oz |
|---|---|---|---|---|---|
| Indicated | |||||
| 1.0 Vein | 1,805,000 | 15.79 | 916,400 | 297.84 | 17,286,200 |
| 1.1 Vein | 683,000 | 5.18 | 113,800 | 69.87 | 1,534,500 |
| Total, Indicated | 2,488,000 | 12.88 | 1,030,200 | 235.26 | 18,820,700 |
| Inferred | |||||
| 1.0 Vein | 728,000 | 12.80 | 299,600 | 188.31 | 4,408,000 |
| 1.1 Vein | 245,800 | 4.57 | 36,100 | 62.44 | 493,400 |
| Total, Inferred | 973,800 | 10.72 | 335,700 | 156.53 | 4,901,400 |
Since the resource estimate was made, Andean has carried out additional drilling, focusing on the western limit of current exploration of the West Vein.
During the Phase 5 drill program, commencing in October 2008, the Company plans to continue infill drilling at Eureka West, in addition to further drilling on the 721 Vein and the newly discovered Evita Vein.
721 Vein
During the Phase 4 drill program, Andean continued to further test the 721 Vein, of which the discovery hole EDD-721 intersected 17m of 9.2 g/t gold and 69 g/t silver in June 2007. The results of the recent drilling campaign included:
- EDD-805: 3m of 6.5 g/t gold and 67 g/t silver from 130m
- EDD-832: 2m of 9.2 g/t gold and 5 g/t silver from 87m and 2.7m of 12.4 g/t gold and 2 g/t silver from 135.3m
The drill holes testing the depth of the 721 Vein indicated that the mineralisation is truncated at depth by a similar ignimbrite sequence to the one intersected below the West Vein, however one hole returned encouraging narrow, high-grade intercepts just above this contact:
- EDD-824: 1.45m of 22.8 g/t gold and 293 g/t silver from 251.8m 0.7m of 11.1 g/t gold and 14 g/t silver from 264.3m
Evita Vein
On July 7, the Company announced the discovery of the new Evita Vein, with drill hole EDD-868 returning values of 9.0m of 13.7 g/t Au and 61 g/t silver, discovered at 190m below surface in the hanging wall of the Eureka West Vein at its eastern end. Further drill testing has been allocated for Phase 5 drilling, scheduled to commence in October, when the winter months have passed and full access to the site has be re-gained.