Garson is a deformed Contact-style deposit. Contact-style mineralized zones are remobilized into a series of near-parallel ductile shear zones. Shear-hosted copper–nickel sulphides are offset by later stage dykes and possible late-stage shearing. The 1 Shear and 4 Shear are the primary mineralized zones. The 1 Shear extends from surface to below 6500 Level, a distance of approximately 1,980 m. It has a strike length of 120–600 m, with strike length decreasing with depth. Hanging wall to footwall widths along the orebody vary between 3–60 m, with an average width of 10 m. The 4 Shear extends from the 2800 Level to a currently known limit of 6700 Level, a distance of approximately 1,200 m. It has a strike extent of 685 m and an average width of 7 m. It strikes east– west and generally dips 70° south. The 4 Shear orebody runs parallel to the 1 Shear orebody, lying approximately 45 m to 60 m to the northwest. Both shears dip at a slightly shallower angles than the SIC contact, which means that above the 4000 Level the shears are mostly hosted in the SIC with the dominant lithology being Sublayer Norite and below the 4000 Level the shears cut the metasedimentary and metavolcanic Huronian footwall rocks. The deposit is crosscut by two separate olivine diabase dykes. These dykes are sub-parallel to each other and range in width from 15–60 m. STRUCTURE The Garson region was subjected to significantly more structural activity than the rest of the Sudbury Basin. This structu ........

The Garson deposit includes the actively mined McConnell deposit, surface ramp (13 and 360), and Garson mine #1 Shear, #4 Shear deposits. Inactive deposits include the Garson ramp (600) zones. Slot–slash and Uppers retreat mining methods are employed for ore extraction. Alluvial sands are used for backfilling. A high density hydraulic backfill is used which introduces much less water into the Main mine than typical hydraulic backfill. Slot–Slash Slot–slash mining is a bulk mining method that entails blasting vertical slices of ore to a free face, which initially will be a blasted inverse raise, or a bored raise. The amount of ore that can be blasted at any given time is limited to the existing void space and the available free face. Blastholes are loaded with staggered decks to break anywhere from 6 m to the entire length of the hole. The blocks are slashed out to the stope boundaries and up to a crown. The final crown is taken in one blast. This method concentrates loading and blasting operations, and, once a slot has been established, stopes of 25,000–40,000 t of ore can be completely broken in 3–5 separate blasts, while smaller stopes can be blasted in one blast. Blastholes are drilled using in-the-hole (ITH) drills. Prior to blasting, long blastholes are surveyed in order to determine their location and all holes are probed with a conductivity probe to confirm ore limits. If required, new holes are drilled to reduce burdens created by drilling inaccuracy and to bl ........

Clarabelle Mill In 2017, the crushing plant and rod mill circuit was put on care and maintenance and the Clarabelle Mill became a SAG-only operating plant. The ore feeds the semi-autogenous grind (SAG) mill where ore is ground with added water. Discharge passes through a trommel; coarse trommel oversize material is transferred back to the tipple building by conveyor, while the trommel undersize is pumped to vibrating screens located near the feed of the SAG mill. Screen oversize is fed back into the SAG mill while the screen undersize is pumped to the ball mill feed distribution pumping system; Product from primary grinding circuit feeds the ball mill feed distribution system, which can send slurry to the cyclone feed pumpboxes of six ball mills. Each ball mill in combination with its own cyclone system grinds the material to a target of 80% passing 150 µm (106 µm for sulphides). Once the material is ground to the correct size, the slurry is sent to flotation.

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