There are three main mineralized zones at Mount Pleasant, namely: the Fire Tower Zone, Saddle Zone and North Zone, from south to north. At depth, the Fire Tower and North Zones have been subdivided as shown in a schematic longitudinal section (Figure 15).

The Fire Tower Zone and North Zone deposits are located approximately 1.0 km apart and are mostly less than 400 m vertically from surface. The Fire Tower Zone contains predominantly large (low grade) tungsten-molybdenum deposits and was previously mined underground for tungsten. Some small indium-bearing tin-base metal zones are also present. The North Zone contains the most important indium-bearing, tin-base metal "resources" outlined to date along with some poorly defined low-grade tungsten-molybdenum bodies (ADEX 1995). The Saddle Zone, located approximately halfway between the Fire Tower Zone and the North Zone, contains tin and some base metals and newly discovered tungsten-molybdenum mineralization.

North Zone
The tin and porphyry tungsten-molybdenum deposits of the North Zone represent two different periods of mineralization even though they overlap spatially. Indium-bearing tin-base metal zones in the North Zone appear to be principally associated with sphalerite and are more concentrated in the Deep Tin zone (Figure 16). The principal metallic minerals in these deposits are cassiterite, arsenopyrite, lollingite, sphalerite and chalcopyrite with lesser amounts of stannite, pyrite, marcasite, galena, wolframite, molybdenite, tennantite, chalcocite, bornite, native bismuth, bismuthinite and wittichenite.

Saddle Zone
Tin-base metal mineralization was discovered in the Saddle Zone during a 1988 surface drilling program that was initiated by Lac Minerals because tin mineralization was encountered underground, during development work between the Fire Tower Zone and the North Zone (Sinclair 1994). A 40-metre section in hole LNZ-15, within Granite IIA, graded 0.33% Sn. Subsequently, NovaGold Resources intersected a 16-metre section, also within granite, of 1.31% Sn in drillhole NMR-89-1; this hole also intersected W-Mo-Bi mineralization within quartz-feldspar porphyry adjacent to this granite (Sinclair, 2011). Holes drilled during the 2011 campaign show that tin mineralization has greater extent than previously known (Figure 19) and that tungsten-molybdenum mineralization is also present.

Fire Tower Zone
The Fire Tower Zone is a tungsten-molybdenum deposit that contains three distinct zones: Fire Tower North, Fire Tower West and Fire Tower South. The tungsten-molybdenum deposits in the Fire Tower Zone mainly occur in the lower part of the breccia pipe and the upper part of the underlying fine-grained granite, and to a lesser extent in associated volcanic rocks (Kooiman et al, 2005). These low-grade porphyry-type deposits are characterized by extensive stockworks of mineralized fractures and quartz veinlets. Higher grade zones occurring in areas of intense fracturing measure 200 to 300 m across and as much as 100 m in vertical extent. The high-grade zones are surrounded by lower-grade zones that are characterized by more widely spaced fractures that extend for hundreds of metres into the surrounding rocks.

Mineralization occurs as veinlets and disseminated grains in breccias mainly located within the Mount Pleasant porphyry. The principal "economic-type" minerals are fine grained wolframite and molybdenite, along with minor amounts of native bismuth and bismuthinite.
The gangue minerals consist of cassiterite, arsenopyrite, lollingite, quartz, topaz and fluorite. Multi-stage mineralization is indicated by crosscutting relationships between mineralized fractures and veinlets. Sparse molybdenum-bearing fractures in fine-grained granite appear to represent the final stage of mineralization associated with crystallization of this granite. Finally, the tungsten molybdenum deposits appear to predate crosscutting dykes of unmineralized granite porphyry that truncate mineralized stockwork zones.

Some small indium-bearing tin-base metal zones are also present. The characteristics of the indium-bearing tin-base metal deposits hosted within the Fire Tower Zone have been best described by Kooiman et al. (2005). These deposits occur as irregular veins and mineralized breccias that are irregularly distributed throughout the Fire Tower Zone and are associated with altered and mineralized granite porphyry dykes. Throughout the Fire Tower Zone, the tin-base metal deposits either crosscut or truncate tungsten-molybdenum stockworks. In general, veins range from 1 to cm in width and up to several metres in strike length. In places, larger veins up to 10 m in width and 100 m long can occur. Veins pinch and swell along strike and contain abundant chlorite and fluorite and disseminated massive sulphides.

Mineralized breccias are irregular bodies and occur as small vertical circular pipes up to 10 m wide and 100 m in vertical extent. These breccias can contain fine-grained sulphides and cassiterite as well as chlorite and fluorite.

The indium-bearing tin-base metal veins and breccias contain the principal oxide minerals cassiterite and wolframite. Sulphide mineralization consists mainly of sphalerite, chalcopyrite, galena and arsenopyrite and minor amounts of pyrite, lollingite, molybdenite, tennantite, native bismuth and bismuthinite.

An open stope concept with temporary rib pillars with no backfill is recommended as a primary mining method for the tin-indium-zinc deposits of the Deep Tin Zone and Upper Deep Tin Zone. The stope sizes and mining limits would be based on the resource block model interpretation.

Stope sizes would vary widely and would produce from several hundred tonnes to a few ten thousand tonnes of ore and would be relatively narrow. Each stope would have an extraction drift, which would be positioned in parallel to the undercut drift with a series of draw points connected with the undercut.

In a typical stope, rows of 62.5 mm diameter production drill holes arranged in fans would be up drilled from the undercut. On a sublevel above rows of 87.5 mm diameter holes would be down drilled to follow the configuration of the stope walls and would account for the bulk of production volume for a given stope. The undercut production holes would be charged with explosives and blasted in vertical slices starting from the end of the undercut and sequentially progressed towards the limit of the stope. In a delayed sequence, the down holes drilled on the sublevel above would be charged with explosives and progressively blasted to follow the stope undercut advancement.

Only partial blast swell would be removed from the stope to provide free space for each consecutive blast. The broken ore in the stope would provide temporary passive support for the stope walls in order to prevent wall slough and to control dilution during the entire stope cycle. At the end of the mining cycle each stope would be completely mucked out and left empty. Some of the empty stopes would be filled with waste rock generated from ongoing development works in the mine.

The maximum height of the stopes, in a single lift from sublevel to sublevel, would be approximately from 15 to 20 metres. Final stope heights in some cases would triple the single lift. Loading of the broken ore onto the trucks would be done with LHD machines. The trucks would haul the ore via the decline up to the surface to the ore storage pile.

A conventional two-stage crushing plant is used to reduce the size of the run-of-mine ore to the required size for grinding. Since an autogenous grinding circuit is not used in the proposed process, pebble production that was used in the past Billiton operation is not required. The run-ofmine ore is not crushed in the mine, and is stockpiled in an outdoor ore storage pile at the plant. The crushing circuit consists of portable equipment located outdoors. The primary jaw crusher will have a grizzly feeder to remove any oversize ore that requires rock breaking. After primary size reduction by the jaw crusher, the crushed ore is conveyed to a screen with the oversize material being fed to a secondary cone crusher for final crushing. The secondary crusher product is conveyed to the same screen to remove the finished undersize material and to recycle the oversize material to the secondary crusher. Final crushed ore is stored in a fine ore storage silo.

A conventional two-stage r ........