The DSO deposits were derived from the iron-bearing sediments of the Sokoman Formation and Ruth Formation. The ores, comprising blue and red hematite with goethite and limonite, were formed by the leaching of the gangue minerals such as chert, silicates and carbonates. Of the 22 different deposits that constitute the Project, ten selected deposits were drilled in 2008 and 2009. Drilling yielded 64.1 million tonnes of proven and probable reserves. There are 11.75 million tonnes of inferred resources remaining. In addition, about 40 million tonnes of historical resources will be drilled to expand the resource base.

The mining method selected for the DSO Project is conventional open-pit mining with a front-end loader/truck operation. The rock will be drilled, blasted and loaded into haul trucks that will deliver ROM ore to the primary mineral sizer, located at the Timmins Site. From each pit, waste will be hauled to an out-of-pit waste dump to be located nearby. Overburden removal and ore and waste mining operations will take place 24 hours per day, 365 days per year but, for loader and truck calculation purposes, it was assumed that inclement weather will shut down operations for an average of five days per year.

The open pit would have a surface area of approximately 78 hectares and a maximum depth of 195 metres. The total footprint of the Project, including the open-pit, waste rock piles, overburden stockpiles, and other infrastructure, would be approximately 200 hectares.

Covering a surface area of approximately 78 hectares, the open pit dimensions would be approximately 1600 m long and 450 m wide at the top, with a maximum depth of 195 m. The open pit would have walls with slopes between 35 degrees (overburden layer), 40 degrees (iron deposit below the water table), and 45 degrees (iron deposit above the water table). The pit would be constructed with ten metre high benches through the iron deposit with a minimum width of 6.5 m.

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