The Sugar Zone is an epithermal deposit located in the Sugar Deformation Zone, or SDZ, which is an area of high strain.  The Sugar Zone, along with the Wolf Zone, make up the only two known gold deposits within the relatively small SDZ, and the only two currently known gold deposits within the Dayohessarah Greenstone Belt.  

The auriferous Upper and Lower zones of the Sugar Zone lie within the SDZ.  They are defined as highly strained packages consisting of variously altered mafic volcanic flows, intermediate porphyritic intrusions and boudinaged auriferous quartz veins. The two zones range in true thickness from about 1.5 to 10 m, and are separated by 20 to 30 m of barren volcanics.

Each zone is made up of one or more porphyritic intrusions, flanked by altered basalt and hosting stratigraphically conformable quartz veins. Alteration within the mafic volcanic potions of the zones consists primarily of silicification (both pervasive and as quartz veining), diopsidation and biotization. The porphyry units of the zones exhibit biotite and silica alteration as well, but no diopside alteration.   

The Upper and Lower zones appear geologically consistent both down dip and along strike. The Lower Zone has consistently larger widths, as well as mostly consistently higher grades of gold mineralization, however both the width, and the gold grade within each zone seem to follow the same trends across the zone.  That is to say, that where the Upper Zone exhibits larger widths and higher gold grades, the Lower Zone also exhibits larger widths and higher gold grades. The zones are observed on surface to pinch and swell over distances of 50 m or more.  

Gold mineralization mostly occurs in quartz veins, stringers and quartz flooded zones predominantly associated with porphyry zones, porphyry contact zones, hydrothermally altered basalts and, rarely, weakly altered or unaltered basalt within the Upper and Lower zones. 

Fine to coarse grained specks and blebs of visible gold are common in the Sugar Zone quartz veins, usually occurring within marginal, laminated or refractured portions of the veins. The visible gold itself is often observed to be concentrated within thin fractures, indicating some degree of remobilization. Quartz veins and floods also contain varying amounts of pyrrhotite, pyrite, chalcopyrite, galena, sphalerite, molybdenite and arsenopyrite. The presence of galena, sphalerite and/or arsenopyrite is a strong indicator of the presence of visible gold. Pyrite, chalcopyrite and, rarely, molybdenite form a minor component of total sulphides and do not appear to be directly related to the presence of gold mineralization.

Other mineralized zones have been observed between, above and below the Sugar Zone Upper and Lower zones, in diamond drilling. Most of these intercepts are believed to be quartz veining originating in either the Upper or Lower zone, that have been diverted from the sheared part of the zone, up to 15 m from the main bodies of mineralization.  One of these zonesisthe historically discovered Zoe Zone, which has been recently renamed the Lynx Zone, which lies east of the southern end of the Sugar Zone.

The auriferous Wolf Zone lies along strike of the Sugar Zone, and may represent the northern extension of the SDZ. It is defined as highly strained packages consisting of variously altered mafic volcanic flows and gabbros. The zone ranges in true thickness from 0.5 to 8 m.

Gold mineralization mostly occurs in quartz veins, stringers and quartz flooded zones predominantly associated with porphyry zones, and hydrothermally altered basalts and gabbros. Fine grained specks of visible gold are occasionally observed in the Wolf Zone quartz veins. The visible gold itself is often observed to be concentrated within thin fractures, indicating some degree of remobilization. Quartz veins and floods also contain varying amounts of pyrrhotite, pyrite and occasional galena. The presence of galena is a strong indicator of the presence of visible gold. Pyrite and pyrrhotite form most of the total sulphides, but do not appear to be directly related to the presence of gold mineralization.

The Sugar Zone would be mined at a planned production rate of 750 tonnes per day of potentially economic mineralization or 270,000 tonnes per year.  The mine would be accessed by a main access ramp from surface to facilitate movement of equipment, rock, manpower and materials to and from the mine.

Levels would be developed from the ramp at approximately 100 metre vertical intervals.  Each level would be developed with an access from the ramp to the mineralized zone and a FW drift located in waste, over the entire length of the mineralized zone to be mined.   All potentially economic mineralization would be loaded on to underground haul trucks and trucked in the ramp, to surface.  

The mining methods would be Alimak Vein and Shrinkage mining with hydraulic backfill.

ALIMAK NARROW VEIN MINING
Mining horizons would be developed on each main level (100, 200, 300 , 400 , 500 , 600 and 650 Levels) Each Alimak vein stope would be  30 metres along strike with 1 drawpoint per stope in the centre, from the footwall drift. 

An undercut over the full width and length, on the lower main level of the potentially economic mineralization block, would be developed. An Alimak raise would be driven in the centre of a stope from the undercut to the level above the stope. The raise would be screened over its entire length to facilitate drillers working in the raise. Cable bolts would be installed into the hanging wall of the stope, from the Alimak platform in the raise, to support the hanging wall. The Alimak installation would be left in the raise and a longhole ring drill installed on the work platform of the Alimak. The longhole drill would drill 70 mm horizontal drill holes (approximately 13.5 metres in length) parallel to the footwall and hanging wall of the potentially economic mineralization. Drill holes would be loaded with ANFO and Nonel detonators and blasted in horizontal slices into the undercut below. Access to stope raises to allow workers to perform drilling and blasting functions on the Alimak, would be from the level above the stope. Broken potentially economic mineralization would be mucked from the undercut by LHD’s and transported to truck loading stations.   

Stope undercut sills would be developed to full width of the zone to be mined by 3.5 metres high. The openings would be drilled with 2 boom E/H jumbos and mucked with 3.1 cu. m. bucket LHD’s.  
Ground support would consist of 1.5 metre mechanical rockbolts and screen.

Mined out stopes would be backfilled with cemented (primary stopes) and uncemented (secondary stopes) hydraulic backfill.  

SHRINKAGE MINING
Mining horizons would be developed every 50 metres vertical elevation. Each shrinkage stope would be 30 metres along strike with 2 drawpoints per stope, developed on 15 metre centres, from the footwall drift. 

Ventilation would utilize raises at each extremity of the mineralized zones being mined for fresh or return air and the ramp as an exhaust for return air, with a push-pull ventilation arrangement.

The flowsheet alternatives are expected to be:

1) Gravity concentration followed by flotation, with cyanidation of both concentrates to produce doré.

2) Gravity concentration followed by flotation and shipment of a combined or separate concentrates to a smelter or toll mill. This option eliminates the use of cyanide on site and may allow an earlier startup. Some doré could be produced on site by smelting a high grade gravity concentrate.

3) Gravity concentration followed cyanidation of gravity tailings.

Crushed ore is ground to a K80 of 80 microns in a two stage grinding circuit at a rate of 824 t/d (273,750 t/a). A gravity recovery circuit is incorporated within the grinding circuit for recovery of free gold. The gravity concentrate is leached separately and the product directed to the Merrill-Crowe circuit.

Ground product from the grinding circuit is directed to a rougher flotation circuit for recovery of gold. The rougher concentrate is reground and cleaned in one stage with the cleaner concentrate pumped to a cyanidation circuit. A conventional cyanidation - Merrill Crowe circuit extracts and recovers gold as a precipitate. The precipitate is smelted to yield a doré product. 

A tailings management & storage area would be constructed near the processing plant with dams initially constructed to start the mine and the dam(s) height(s) increased during the mine life as required.