VMS deposits are also known as volcanic associated, volcanic-hosted, and volcano sedimentaryhosted massive sulphide deposits. They typically occur as lenses of polymetallic massive sulphide that form at or near the seafloor in submarine volcanic environments, and are classified according to base metal content, gold content, or host-rock lithology.

The Horne deposit is the largest Canadian Au rich VMS deposits in the Noranda district (331 tonnes of Au produced historically from 54.3 Mt of ore at 6.1 g/t Au; Kerr and Gibson, 1993).

The typical morphology of Au-rich VMS deposits consists of a lenticular massive sulphide body with associated underlying discordant stockwork-stringer feeders and replacement zones. At Horne, zones of auriferous sulphide veinlets with Fe-chlorite selvages account for some of the Aurich mineralization (Kerr and Mason, 1990), however, the deposit lacks a well-defined stringer zone (Poulsen et al., 2000).

The vertical extent of the stockwork is typically larger than its lateral extent. The lateral extent of the deposit is typically a few hundred metres, but in some cases where the deposits are overturned, the mineralization has more than 2 km of known vertical extent (Horne and LaRonde Penna deposits). The thickness of the massive sulphide lenses is highly variable, especially when subjected to deformation (shortening), but is commonly on the order of a few tens of metres.

Mineralization is typically hosted b ........

The main mining methods selected for Horne 5 Project are transverse long hole stoping with primary and secondary sequence. This selection is based on the geometry of the mineralized zones, their vertical dip and the competency of the rockmass to allow high production rate. Some sectors are also mined using longitudinal long hole retreat and pillarless sequences.

This mining method involves accessing stopes using two transverse draw points: one above the stope for drilling and loading of bulk explosives, and one below for extracting blasted material. The empty stope is then backfilled to allow mining of the adjacent stopes. Stopes will be mined according to a primary/secondary sequence, thus increasing flexibility and productivity while ensuring rock stability. For levels L1310 to L1030, the thickness of the ore zones (approximately 100 m) permits the haulage drifts to be excavated inside the ore zone thus reducing waste and initial capital cost, and accelerate the mining schedule. So, a longitudinal retreat mining sequence will be used for the last stope of each draw point on these levels.

Stope dimensions will vary with depth to reduce the potential dilution and the risk of seismicity.

The transverse long hole mining method allows for a high degree of mechanization and automation and is amenable to tele-operation. Production technicians will be able to operate LHDs from a control room at surface, resulting in higher equipment usage rates, be ........

- subscription is required.

- subscription is required.