Exploration Programs
2010 Exploration Program
Capstone has approved a budget of approximately US$5.3 million focused on Minto East, Copper Keel, Area 2 and Titan 24 targets.
This work will support the evaluation of a proposed underground mining option, targeting high grade mineral resources that are adjacent to or below the open pits outlined in the Phase IV Preliminary Feasibility Study ("Phase IV PFS"), the results of which were announced on December 15, 2009.
Capstone completed and expanded Titan-24 geophysical survey (please refer to September 1st, 2010 News Release) with Quantec that covered approximately 80-85% of the Minto mine property and defined 73 targets, including 19 high priority targets.This geophysical tool represents another opportunity for Capstone to refine and expand its targeting of anomalies.
Please follow the link below to a map identifying the priority exploration areas for 2010:
http://www.capstonemining.com/i/photos/minto/2010-04ProposedMintoDrillProgram.jpg
Please follow the link below to a map identifying the priority exploration areas for 2010 showing Titan 24 IP chargeability at 700m elevation:
http://www.capstonemining.com/i/photos/minto/2010-04ProposedMintoDrillProgram700elTitanIP.jpg
Please follow the link below to a map identifying the priority exploration areas for 2010 showing airborne magnetics:
http://www.capstonemining.com/i/photos/minto/2010-04ProposedMintoDrillProgramMag.jpg
2008 Exploration Program
Sherwood has budgeted a $4.4 million, 20,000 metre drill program for 2008 with the following priorities:
- Evaluate the potential of the Upper Minto Valley for new discoveries (complete);
- In-fill drill the 2007 discoveries at Area 118 and Ridgetop to increase the resource confidence level;
- Step out drilling in the Area 2, Area 118 and Ridgetop areas with the objective of expanding the known mineralization into previously untested areas;
- Test other targets.
To date, results have been reported from thirteen holes drilled in the Upper Minto Valley, a previously unexplored and large area west of the Minto and Area 2 deposits. New copper-gold intercepts were encountered opening up potential for discoveries in previously unexplored areas on the Minto property. Drilling has now moved on to other priority areas identified in 2007, including possible extensions to the Area 2 deposit, further definition of the Area 118 and Ridgetop discoveries to increase the resource confidence level, as well as exploring additional targets. The 2008 exploration program is a component of our overall strategy to maximize the value of the Minto Mine by developing additional high grade reserves that could justify further increases in production by increasing mill throughput.
2008 Drill Hole Location Map
2007 Exploration Program
Sherwood's successful 2007 exploration program delivered high grade copper-gold mineralization from a number of targets. The program was carried out in two phases and was comprised of 91 exploration drill holes and 10 geotech/metallurgical drill holes totalling 23,292 metres of diamond drilling. Significant new copper-gold mineralization was discovered at the Area 118, Copper Keel, Airstrip and Ridgetop prospects and in the Gap between the Minto Mine and Area 2. Each of these areas has the potential to provide additional near surface resources beyond those considered in the December 2007 pre-feasibility study. Mineral resource estimates incorporating the results of the 2007 drilling are underway. In addition to near surface mineralization, several deeper high grade intersections at the Minto Mine are opening up the vertical dimension to this highly prospective property, a dimension that has received little exploration attention in the past. Highlights of each phase are as follows:
Phase 1 Highlights:
Phase 1 was completed in May 2007 and consisted of six deep exploration holes totalling 2,259m and five metallurgical drill holes totalling 443m.
- Six deep exploration holes tested the 'Gap' target between, beneath and adjacent to the Minto Mine and Area 2 resource areas. The 6 exploration holes confirmed the presence of multiple, stacked, foliated and mineralized horizons throughout the 'Gap' target area and suggests there is reasonable geological continuity between the two areas;
- Five metallurgical drill holes were drilled in the southern part of the Minto Mine reserve to collect metallurgical sample material for the current grinding optimization study. These holes equalled or exceeded grades and thicknesses projected from the resource model, including another exceptional gold intercept grading 46.2g/t gold over 1.1m and significantly higher than expected copper grades in another hole.
2007 Phase 1 Drill Hole Location Map
Minto-Gap-Area 2 Cross Section
Phase 2 Highlights:
Phase 2 commenced in June and was completed in October with a total of 85 exploration drill holes and 5 geotech holes for 20,917m of drilling completed. The objective of the Phase 2 exploration program was to more fully define the limits of the Area 2 deposit and provide technical information for the PFS, but mostly to broadly test a wide swath of the Minto property to the south, west and between the Minto and Area 2 deposits. Significant new copper-gold mineralization was discovered at at the Area 118, Copper Keel, Airstrip and Ridgetop prospects. In addition, an extensive geophysical program was completed. Highlights from Phase 2 include:
- Ridgetop - located approximately 1km south of the Minto open pit, assay results confirmed the presence of near surface (3-12m deep) copper-gold mineralization, including chalcocite enrichment zones, over significant thicknesses. Results included 10.3m of 2.72% copper and 1.37 g/t gold, 7.5m of 2.08% copper and 0.81 g/t gold, and an exceptionally thick, near surface intersection of 88.8m grading 0.75% copper including 13.7m of 2.04% copper.
- Area 118 - located approximately 350m south of the current open pit and immediately adjacent to the Area 2 deposit, Area 118 is a large system, measuring more than 500m by 200m in aerial extent. Preliminary interpretations of drilling to date favour a fault model in which the Area 118 mineralization is equivalent to the deeper Area 2 horizons that are now faulted upward and juxtaposed against upper Area 2 mineralization. 2007 drilling indicates the presence of a higher grade core within the Area 118 deposit and provided further confirmation of high grade copper-gold mineralization where the Area 118 and Area 2 deposits join. Results included 9.1m of 3.40% copper and 0.87g/t gold and 15.0m of 3.09% copper and 1.03g/t gold.
- Airstrip SW-Copper Keel - located approximately 500m east of Ridgetop, this prospect was thought to comprise two separate targets but now appears to be one system with two markedly different styles of copper mineralization. One is the chalcopyrite-bornite-magnetite-gold mineralization typically found throughout the Minto project. The second type is coarse grained chalcocite-gold (+/- native copper) associated with mixed iron oxides. Results included 4.1m of 3.10% copper and 2.27 g/t gold starting at only 68.2m below surface and 2.79% copper and 0.93g/t god over 4.2m starting at only 99.9m below surface.
- Potential Area 2 expansion to the southeast - Hole 07SWC-269 stepped out more than 110m to the southeast of the nearest 2006 Sherwood hole used in the Area 2 Pre-feasibility Study, opening up the potential for a near surface expansion of the Area 2 deposit. The drill hole encountered shallow, high grade mineralization which is in close proximity to the Area 2 reserves. The good grades and shallow depths of this mineralization in an area immediately adjacent to Area 2 make this a high priority target for drill testing in 2008 and could lead to potential resource expansions.
- Gradient IP Geophysical Survey - results include the definition of a large chargeability anomaly in an under-explored area that was previously thought to be of low prospectivity. The edge of this new anomaly correlates with recent drill discoveries of high grade copper-gold mineralization at Airstrip and Copper Keel, suggesting additional potential beyond the scope of recent drilling. Also of potential significance are several newly identified chargeability anomalies located north of the main Minto pit, indicating exploration potential north of the Minto Mine, in areas that have received only very cursory exploration drilling.
2007 Phase 2 Drill Hole Location Map
Detailed Gradient IP -- Sept 2007
Mineral resource estimates incorporating the results of the 2007 drilling are underway and all 2007 drill information was used to lay out the priorities for a significant 2008 exploration program to follow up on the exciting 2007 discoveries. Given the very encouraging 2007 exploration drill results, there would appear to be excellent opportunities for further resource additions that could potentially support additional production expansions or an increased mine life.
2006 Exploration Results
In 2006, Sherwood completed a total of 24,252 metres (79,567 feet) of NQ diamond drilling in a two-phase program.
- Phase 1 comprised 4,129 metres of resource definition drilling within the main deposit and a limited amount of exploration drilling. The resource definition drilling was successful in confirming higher gold grades in the northern 1/3rd of the Minto deposit and three of the five exploration holes resulted in the discovery of a significant new body of mineralization -- the "Area 2" discovery.
- Phase 2 was planned as a 16,500m exploration program focused on several exploration targets outside of the main Minto deposit. Given the outstanding results from Area 2, the program was expanded to 20,123m and resulted in the delineation of a significant zone of high grade copper-gold mineralization at the Area 2 target, approximately 130m from the open pit (click here). Drilling extended far beyond of the initial target area and a significant new resource was defined.
- The total contained metal in the Area 2 Measured and Indicated Resource estimate represents a 61% increase in contained copper and a 75% increase in contained gold versus the resource estimate for the main Minto deposit at a 0.5% copper cut-off.
- Area 2 is being advanced through a pre-feasibility study with the objective of adding to the high-grade reserve base during Q3/2007. It remains open to expansion in a number of directions, offering further potential beyond that defined to date.
- A summary of the 2006 drilling is set out in the table below:
| Area |
Purpose |
No. of Holes |
No. of Metres |
No. of Feet |
| Minto Deposit |
Resource Delineation and Confirmation |
20 |
2,433 |
7,982 |
| Area 2 |
Discovery/exploration & resource delineation |
79 |
18,376 |
60,289 |
| Other Targets |
Testing targets other than Area 2 |
20 |
3,443 |
11,296 |
| |
Totals |
119 |
24,252 |
79,567 |
2005 Exploration Results
Approximately 6,772m of drilling were completed in 2005 consisted of 57 drill holes including:
- 20 confirmation diamond drill holes within the resource limits;
- 16 step-out diamond drill holes beyond prior resource limits (to the south and west);
- A number of reverse circulation and geotechnical holes to test the proposed waste dump, tailings disposal area, and to assist in pit optimization work .
The 2005 drill program was successful in confirming the existing resource, expanding the high grade Minto copper-gold deposit beyond the limits of prior drilling, upgrading inferred resources within the prior pit limits to the indicated category, and in providing strong evidence for significantly higher gold grades than those estimated from previous drilling.
