SAN DIMAS

EXPLORATION

Goldcorp carries out a continuous program of exploration to convert resources into reserves. The program usually involves more than 35,000 meters per year of diamond drilling and more than 23 kilometers per year of drifting including exploration, preparation and infrastructure.

Typical of epithermal systems, the silver and gold mineralization of the San Dimas district exhibits a vertical zone with a distinct top and bottom that Luismin has termed the Favourable Zone.  This Favourable Zone was deposited in a horizontal position paralleling the erosional surface of the LVG on which the UVG was extruded. 

This Favourable zone at San Dimas is some 300- 600 metres in vertical extent and can be correlated, based both on stratigraphic and geochronologic relationships, from vein system to vein system and from fault block to fault block.  Using this concept of the dip of the unconformity at the base of the UVG, Luismin is able to infer the dip of the Fabourable Zone and with considerable success explore and predict the Favourable Zone in untested areas.

Following Wheaton’s purchase of the properties, exploration and development activity has been substantially increased to provide for an increase in milling capacity to 2,100 tonnes per day by 2009. Exploration campaigns initiated since the purchase have already shown success and mill expansion.

Exploration is focused on the high grade zone of Central Block Mine and western extension of the veins through Sinaloa Graben Project where one new tunnel are being driven to enable more detailed exploration to be carried out and to provide the infrastructure to develop more than ore 20 veins and also. One of the high grade areas is between the Roberta and Castellana veins (more than six veins) where diamond drilling has indicated that extensions to the economic zone could reach more than 0.5 kilometre in length and also exploration is focused on the Arana Hanging Wall as part Tayoltita Mine where the current diamond drilling is looking forward to find new veins.

Three relevant intersections were achieved at the Sinaloa Graben Block during the third quarter of 2009. The objective of exploration drilling at the Sinaloa Graben is to intersect the western extension of the Central Block.

The San Francisco ore pass was completed during the third quarter of 2009 and is now in use and providing operating efficiencies in ore haulage.

The exploration targets for the next five years are:

• The Central Block from Piaxtla River to Noche Buena vein. More than 7 kilometres
• The Sinaloa Graben west side – an extension of the Central Block vein system, around 5 kilometres of development
• The Arana hanging wall block between Tayoltita and Santa Rita mines, an area of  2 kilometres between both mines
• The West Block including the western part of the San Vicente- Luz y Reyes area
• The La Verdosa-El Cristo area.