The Taborny deposit is a structurally controlled zone of potassic metasomatism, hosted by Proterozoic sandstones. The mineralised zone dips moderately to the south and southsoutheast. Parallel to Taborny, and approximately 500 m south, is the smaller Temny deposit. Between Taborny and Temny are mineralised linking structures, and both deposits are covered by the same block model and one pit design, therefore “Taborny-Temny” is often referred to as a single entity.

Mineralisation at Taborny-Temny is associated with iron and manganese oxides, that follow from primary sulphides, particularly pyrite.

Approximately 1.5 km southwest of Taborny, and hosted by the same Proterozoic sandstone succession, is the Vysoky deposit. The Vrezanny deposit, 4 km west-northwest of Taborny, is also included as a satellite of Taborny, although the geological setting is different from Taborny, being hosted by granite-gneisses of the Archaean basement.

The Taborny, Temny and Vysoky deposits are situated in the western part of the Aldan shield, in the southwestern corner of the Uguskiy Graben. The graben is filled with Lower Proterozoic sediments of the Olonnokonskiy Formation, which discordantly overlie early Archaean gneisses and a later Archaean intrusive complex.

The major regional structural features are: 1) the N-S striking Tokkinsky Fault Zone (along the western margin of the Uguskiy Graben); and 2) WSW-ENE striking faults of the Kondinsky Fault System, which cut across the Tokkinsky Fault Zone, and are broadly parallel to the southern margin of the graben. The Vrezanny deposit is within the Tokkinsky Fault Zone.

In the vicinity of the Taborny-Temny, Vysoky and Vrezanny deposits, the thickness of alluvial and glacial Quaternary cover sediments is negligible; usually no more than 5 m.

Taborny-Temny
Taborny-Temny mineralisation is hosted by the Olonnokonskiy Formation, and in the project area this formation comprises up to 20-30 m of basal conglomerates and gravels, overlain by 300-400 m of fine to medium grained sandstones. The sediments are shallow-dipping to the north, northeast or east.

The Olonnokonskiy Formation host rocks have undergone multiple tectonic and magmatic activation events, dominated by deformation and metasomatism associated with the intrusion of Mesozoic dykes and sills.

The main Taborny and Temny mineralised zones correspond to fault zones which dip moderately towards the south-southeast. The Taborny and Temny fault zones are regarded as part of the Kondinsky Fault System. The intersection of these two fault zones with a third fault zone, dipping steeply to the southeast, and interpreted as a splay from the Tokkinsky Fault Zone, appears to be a key control on mineralisation at the deposit-scale.

Vysoky
The steeply southeast-dipping fault zone that intersects the Taborny-Temny fault zones continues to the southwest. Vysoky, 1.5 km from Taborny, is located close to the intersection of two branches of this fault zone.

As at Taborny-Temny, sandstones and conglomerates of the Olonnokonskiy Formation host mineralisation at Vysoky. Some Vysoky mineralisation is also hosted by syenite sills.

Vrezanny
Vrezanny is within the Tokkinsky Fault Zone, near the eastern edge. The host rocks to mineralisation are granite-gneisses of the Archaean basement. Mineralisation occurs near the intersection of a south-west dipping strand of the Tokkinsky Fault Zone, with an east-west striking fault of the Kondinsky system.

Mineralisation
The following description applies to Taborny-Temny. Mineralisation at Vysoky and Vrezanny has not been described in detail, but key characteristics are assumed to be similar to TabornyTemny.

Mineralisation was introduced by potassic metasomatism. Gold is the only element of economic significance, and is strongly correlated with potassium and arsenic. The dominant sulphide mineral appears to have been pyrite. On average, primary sulphide content appears to have been less than 1%; the sulphides have since been oxidised to limonite to a depth of approximately 400 m.

The gold is seldom visible, and mainly occurs as micron-scale particles.

Taborny is a low-grade gold deposit of which the production cycle includes conventional drilling, blasting, loading, hauling, dumping of waste and stockpiling of ore. Current mining operations at Taborny are mostly focused on a single open pit, supplemented by production of the adjacent Temny and nearby Vysoky pit. The nearby Vrezanny deposit consists mostly of inferred ore and was not included in the reserves.

Open Pit Geotechnical Considerations
The Taborny deposit is located in a mid-mountainous relief, with flat watersheds and intersected by river valleys. The elevations of the watershed surfaces are up to 1400 mRL, the relative elevations usually do not exceed 300-400 m. Natural topographic slope angles are up to 25°- 30°. The thickness of the ore zones is up to 300 m and the ore bodies within the ore zones having thicknesses from a few metres to tens of metres. The maximum depth of the ore bodies from surface is 370 m. The rock mass of the ore zone and the ore itself is highly fractured while the host rocks are represented by fine and medium grained red sandstones with this material being less fractured and more competent.

The Taborny deposit is entirely located within sandstones of the Olonnokonskaya Suite and as such, the entire site had initially an almost uniform lithological structure. Very intensive bedrock fracturing is observed at the deposit, alongside with a high degree of rock weathering on the upper levels (10-20 m thick) represented by random frequent fractures and frequent branching clay zones with the thickness of up to tens of centimetres. Three geotechnical domains have been defined: Zone I, a zone of unaltered or slightly altered sandstones in the northern pit wall; Zone II, the central part of the open pit consisting of the ore zone which is highly fractured; and Zone III, a zone of altered sandstones in the southern pit wall with bedding structure that dips out the slope to the north.

Historically, a two stage crushing circuit was used to crush the ore to a nominal -40 mm and the ore was agglomerated with cement using a drum agglomerator before stacking. As the project developed, however, testwork showed that the ore was less sensitive to crush size than was initially thought, and so as production was expanded, the crushing circuit was simplified to the current -100 mm nominal crush size and agglomeration was discontinued. Further operational experience has shown that omitting crushing completely results in little additional loss in recovery.

Ore designated for crushing is crushed to a nominal -100 mm using two mobile crushers operating in parallel. Both crushers are based on Metso/Nordberg C120 jaw crushers; one unit is a Nordberg NW120 and the other is a Lokotrack LT120. The Nordberg unit is powered by a 160 kW electric motor and is fitted with a 90 mm scalping screen. The Lokotrack unit is powered by a 310 diesel generator and is fitted with a 75 mm scalping screen. Both crushers operate in open circuit.

The Taborny process plant treats low grade non-refractory sandstone hosted gold ore by heap leaching to produce gold doré on site.

The plant commenced production in 2002 and has been upgraded in several stages, with expansion of the metal recovery circuit and simplification of the feed preparation circuit. The nominal design capacity of the plant is now 7 Mtpa based on a high proportion of direct dumped ore.

Heap Leaching
The crushed ore is transported to the leach pads using a series of overland conveyors, feeding onto mobile grasshopper conveyors and final to a radial stacker. Direct dumped ore is delivered to the pads by the mine haul trucks. The maximum lift height is 12 m. Leach solution is applied using wobbler sprinklers during the warmer months and drip emitters, which are buried just under the surface of the heaps, in the colder months. Due to the prevailing climatic conditions, the barren and pregnant solutions are stored in tanks inside the elution ........