Karari was one of the original deposits that constituted the justification for the construction of the Carosue Processing facility in 1999. The pit lies approximately 0.5km to the South of the Carosue Dam processing plant, with all ore being directly hauled to the mill in mining trucks. Historically, this was a high tonnage deposit which lends itself to additional cutbacks and potentially a bulk mining method for an underground operation. Over its four year life 4.7Mt of ore averaging 1.8g/t ~278koz, were mined from the Karari deposit.
The deposit itself is lithologically and structurally controlled and sits within an altered volcaniclastic sandstone unit that has been offset along a series of major faults running NE-SW and NW-SE. The stratigraphy has been intruded by large post mineralization lamprophyre units.
Mineralization is dominated by silica-sericite-pyrite alteration and hosted in broad hematite altered sandstone unit. A series of north plunging high grade ore shoots are developed at the intersection of key mineralised structures.
The Karari pit was first mined in 2000 as one of the start up pits for the then newly established Carouse Dam Operations. Subsequent cut backs on the original pit culminated in stage 3 being completed in 2004. Following on from a rising gold price Saracen initiated studies into the viability of a further cutback at Karari. Mining of stage 4 of Karari commenced in the third quarter of FY2011, continuing for two and half years and mining to a final depth of 210m. Underground mining studies were then undertaken to assess the viability of an underground operation at Karari, which culminated in the establishment of a portal near the base of the most recent open pit cutback in December 2014. In the intervening period ore production has commenced and a substantial underground drilling programs have been undertaken from several underground drill platforms to delineate the Karari system. The results of these programs have outlined the scale of the lateral extent of the ore body which has provided an opportunity for the implementation of a dual decline in the mine design.
A dedicated decline has accessed the northern stoping horizons of the Hangingwall and A1 Lodes, and a second decline has now accessed the southern stoping horizons of the Dhoni Lode.
Total ore tonnes mined have the potential to ramp up from current levels of ~750ktpa to in excess of 1.2Mtpa (~75kozpa to ~115kozpa) due to a combination of the dual decline access increasing stoping horizons, improved equipment utilisation and mining efficiencies, as well as increased strike lengths and widths of both the Dhoni and A1/Hangingwall lodes at depth. This could have a significant impact on the annual production from FY18 onwards and improve the overall profitability and efficiency of the Carosue Dam operations.