SAN DIMAS

EXPLORATION

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

Typical of epithermal systems, the silver and gold mineralization of the San Dimas districk exhibits a vertical zone with a distint 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 2006. Exploration campaigns initiated since the purchase have already shown success and mill expansion design work is well under way. San Dimas is on track to increase mining and processing capability with consequent higher gold and silver production.

Exploration is focused on the Central Block, part of the San Antonio area where three new tunnels are being driven to enable more detailed exploration to be carried out and to provide the infrastructure to develop more than ore 20 veins. 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 1 kilometre in length.

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 hanging wall block between Tayoltita and Santa Rita mines, an area of 4 kilometres between both mines
• the western part of the San Vicente- Luz y Reyes area
• the La Verdosa-El Cristo area.

At the Nukay-Filos district, exploration was increased to identify new resources and convert existing resources to reserves. The program involves more than 18,000 metres per year of diamond drilling, and more than 5 kilometres of development including exploration, preparation and four new tunnels to access the ore zones previously detected by diamond drilling. These new ore bodies were discoveries in the contact between the intrusive granodiorite and surrounding limestone. The prospective area is more than 5 kilometres in length and could extend for more than 500 metres vertically.