The Silvertip mineralization is a silver-zinc-lead Carbonate Replacement Deposit (CRD) with metals content, polyphase mineralization, abundant replacement textures, pyrite pseudomorphing pyrrhotite, and wallrock alteration reminiscent of many of the manto-chimney CRD’s of Mexico and the western US These economically attractive, polymetallic systems can stretch continuously from copper-gold enriched skarns near intrusion contacts in the “proximal” part of the system, to massive sulfide manto and chimney deposits with no exposed igneous relationship in the “distal” areas. Traditionally these deposits have been considered difficult exploration targets due to a paucity of peripheral indicators to mineralization such as hydrothermal alteration or consistent relationships to breccias or structures. Mineralization There are two 'layers' of mineralization identified on the Silvertip Property. A series of older sediment hosted Pb, Zn exhalite deposits hosted in Earn Group sediments overlie a deeper, and younger carbonate replacement Ag, Pb, Zn, Au deposit. This 'lower' deposit is the focus of exploration on the Silvertip Property. The targeted Silvertip mineralization, termed the 'Lower Zone', consists of silver-leadzinc massive sulphide, formed by hydrothermal replacement processes in McDame Group limestone and takes the form of either shallow dipping mantos or sub-vertical chimneys. This lower zone replacement deposit terminates against impermeable shales at the base of the ov ........

There are two portals which allow access to the Silvertip Mine, the historical portal, referred to as Portal 1 (P1), which is used for personnel and material access, and the ventilation intake portal, referred to as Portal 2 (P2) which is also used for emergency egress. The historical ramp was driven with a design profile of 4.27 mW by 4.57 mH and the newer ramp is developed with a design profile of 4.5 mH by 4.5 mW.

The Silvertip mine was designed on the basis of the following key principles:

• Mechanized trackless operation with decline access;
• A production rate building up to 1,000 tpd; and
• A material handling system using truck haulage of ore and waste to surface.

The primary mining method planned at Silvertip for the sub-horizontal manto deposits is cut and fill (CAF). When possible slashing of the walls and backs is utilized to improve ore recovery. This method is ideal for this orebody due to the irregular shape, shallow dip, relatively high grade, and generally poor rock competency. Also, it can limit the exposed span and support the hangingwall.

Longhole stoping is also planned for some of the thicker manto and the vertical chimney mineralization.

CAF is a development-intensive mining method in which parallel drifts are mined in a primary- secondary sequence. After the primary drift is mined, it is backfilled with cemented fill, so that the secondary drift may be mined alongside. The cut and f ........

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