Cerro Negro Gold Project
Herradura
The Herradura area is immediately east of Vein Zone. It has subdued relief and very little outcrop, but extensive areas of quartz float over an area of 600 x 400m, as well as soil geochemical anomalies defined by MIM. Thick gravels obscure a possible eastern continuation to the zone. MIM explored the area with soil geochemistry, geophysics, limited trenching, and twelve RC holes totaling 1632m, plus several other holes peripheral to the main prospect. These holes are widely scattered and at various orientations. Intersections include broad zones of low grade mineralization - eg 21m of 1.51 g/t Au (or 58m, 0.97 g/t) in CNRC-15 as well as other higher grade zones such as 18m of 4.52 g/t in CNRC-57.
The Phase 3 program included four DD holes drilled in the northern part of the Herradura prospect, 250-350m east of Vein Zone. The holes were drilled on two NS sections, as follows:
Phase 3 Herradura holes, collar details
| HDD-601 | 2409150.00 | 4806475.00 | 812.50 | 180 | -60 | 215.50 |
| HDD-703 | 2409150.00 | 4806525.00 | 802.50 | 180 | -60 | 254.85 |
| HDD-704 | 2409050.00 | 4806525.00 | 792.00 | 180 | -60 | 213.00 |
| HDD-602 | 2409050.00 | 4806575.00 | 785.00 | 180 | -60 | 214.70 |
These holes obtained the following intersections at a 0.7 g/t Au cutoff grade and minimum intersection width of 2m:
Herradura drill hole intersections >0.7 g/t Au
| Hole | Interval | Width | g/t Au |
|---|---|---|---|
| HDD-601 | 25-31 | 6 | 1.76 |
| 53-55 | 2 | 1.01 | |
| 75-77 | 2 | 4.64 | |
| 127-130 | 3 | 2.39 | |
| 157-159 | 2 | 2.35 | |
| 202-206 | 4 | 1.36 | |
| HDD-602 | 137-139 | 2 | 1.32 |
| 147-149 | 2 | 1.09 | |
| HDD-703 | 22-25 | 3 | 1.09 |
| 102-104 | 2 | 1.02 | |
| 138-141 | 3 | 2.35 | |
| 156-158 | 2 | 2.73 | |
| 166-169 | 3 | 1.57 | |
| 172-175 | 3 | 0.85 | |
| 202-204 | 2 | 2.11 | |
| HDD-704 | 66-68 | 2 | 2.74 |
| 88-97 | 9 | 2.00 | |
| 104-109 | 5 | 2.90 | |
| 125-127 | 2 | 1.07 |
The best of these intersections included 9m of 2 g/t Au from 88m and 5m of 2.9 g/t Au from 104m, both in HDD-704 on Section 9050E. HDD-602 did not intersect significant mineralization down-dip, but there is some up-dip potential on this section.
On the next section 100m east (9150E) HDD-601 intersected 6m of 1.8 g/T Au from 25m and 2m of 4.6 g/t Au from 75m. HDD-703, drilled down-dip, intersected a number of zones 2-3m wide 0.9 to 2.7 g/T Au.
The four-hole program at Herradura has therefore downgraded the target, and the weak resistivity anomaly probably represents weak stockwork mineralization as exposed in places on the surface at Herradura. However the ignimbrite-tuff contact which is associated with mineralization was not well tested by these holes (three of the holes were drilled entirely in ignimbrite). Any further exploration should try to locate and explore this contact, perhaps by shallow RC drilling.
Additional Potential within the Cerro Negro Tenements
The exploration potential within the Cerro Negro project for additional gold veins is considerable. In addition to the highly prospective Vein Zone area, there are other additional known outcropping epithermal gold systems contained within the 25,000 hectare license area.
In all, previous owners' MIM Limited, identified nine areas prospective for epithermal mineralization apart from Vein Zone, (Herradura, Silica cap, El Buho, El Retiro, Mariana, Mariana Sur, Eureka, Las Margaritas and Bajo Negro ). Only the Vein Zone, Eureka Veins and Marianna have been drill tested to date.
Andean's field teams continue to identify gold mineralization in many of the regional areas. These positive findings support Andean's belief that Cerro Negro has the potential to host more than two gold deposits.
Andean's priorities for its property wide exploration are threefold - first, continue infill drilling at the Eureka Veins to increase the resource; second, to test existing targets in close proximity to Vein Zone to determine their potential to host additional gold resources; and; finally, assess other currently known structures as potential drill targets for future programs.
Other Prospects
Other targets which have received preliminary testing, or none, include:
- Don Adolfo, east of Vein Zone: initial trenching and RC drilling with inconclusive results.
- Pescado Rabioso, north of Vein Zone: Large resistivity anomaly, trenched not yet drilled
- Silica Cap: Large area of silicification and argillic alteration south of Vein Zone: six RC holes drilled previously by MIM with low gold but anomalous indicator elements, no significant exploration by Andean as yet.
- Eureka North: Small quartz and quartz calcite veins to the north of the Eureka vein system: initial testing by four RC holes intersected no significant mineralization.
- Eureka South East: Large vein outcrops with coincident resistivity and geochemical anomalies. Four RC holes failed to intersect significant mineralization.
- Eureka South: Quartz veins with anomalous geochemistry, not yet drilled.