Name: Kundana mine.

Location: Kundana is located in the Eastern Goldfields of Western Australia, 25 km north-west of Kalgoorlie.

Mine Owner/s: Northern Star.

Brief Description: The Kundana operations currently comprise five underground orebodies. The Raleigh orebody is accessed from the Raleigh pit, with underground stoping occurring at more than 650 m below surface.

Three other orebodies – Rubicon, Hornet and Pegasus, – are accessed from the Rubicon pit and portal, with stoping occurring between 200 m and 400 m below surface. Production has also started on the 100%-owned Millennium deposit at Kundana.

Brief History: Prospecting and small-scale mining in the Kundana area started in about 1895. A small town called 21 Mile was established, which later became known as Kundana. Modern mining began in 1988 in the original Kundana South, Kundana North and Strzelecki openpits.

Mineralisation was discovered at the Rubicon project in 1999. The project includes the separate deposits of Rubicon, Hornet and Pegasus, located on strike along the K2 mineralised trend.

The Raleigh deposit, located 2 km to the north-west on the Strzelecki trend, was discovered in 2000. Openpit mining started at Rubicon and Raleigh in 2002.

Underground production from Raleigh started in 2006 and from Rubicon-Hornet in 2011.

Northern Star acquired a 51% ownership stake in the Kundana operations through the acquisition of Gilt-Edged Mining, a wholly owned subsidiary of Barrick Gold, in March 2014.

Primary Metals: Gold.

Secondary Metals: None stated.

Geology/Mineralisation: The Kundana operation hosts several deposits spatially associated with the Zuleika shear zone (ZSZ), a north-west- to south-east-trending structure stretching more than 250 km, separating the Ora Banda and Coolgardie domains.

Typically, deposits within the ZSZ comprise narrow, high-grade quartz veins, hosted within smaller shear structures formed at the contacts of the Archaean greenstone stratigraphy’s belonging to the two domains. Strike extents for each of the deposits are controlled by late-stage north-north-east-trending subvertical structures, exhibiting varying amounts of dextral offset. In total, the Kundana area is known to host more than five-million ounces of gold, including the deposits Raleigh, Rubicon, Hornet and Pegasus.

The Raleigh deposit is hosted within the Strzelecki shear, located at the stratigraphic contact between andesite/intermediate volcanoclastic and gabbro, with varying amounts of interflow sediment.

The main lode comprises a laminated quartz vein of up to 2 m true width and dipping 70 º  west, grading on average 55 g/t gold. Gold is typically associated with sphalerite and galena. The deposit is well defined, with drilling showing economic mineralisation extending up to 750 m below surface.

The Rubicon, Hornet and Pegasus deposits are all hosted within the K2 shear, located at the stratigraphic contact between intermediate volcanoclastic and Victorious basalt, with varying amounts of Centenary shale.

The main lode comprises several mineralising events, which can be distinguished by the presence of laminated or brecciated quartz, and differing amounts of galena, sphalerite, arsenopyrite and pyrrhotite.

Vein grades typically average 25 g/t gold for the main lode, with the structure varying in thickness from 0.5 m to 4 m, and dipping 80 º west. Several hanging-wall lodes with varying orientation have also been identified and exhibit localised ore grades.

All three deposits remain open at depth, with drilling and underground development identifying distinct high-grade zones plunging to the north and south.

Reserves: Total proven and probable reserves as at June 30, 2019, were estimated at 6.41-million tonnes grading 3.2 g/t gold.

Resources: Total measured, indicated and inferred resources as at June 30, 2019, were estimated at 17.77-million tonnes grading 3.4 g/t gold.

Mining Method: Underground using up-hole longhole stoping with paste back-fill.

Major Infrastructure and Equipment: Ore from the Kundana operations is treated at Northern Star’s Kanowna Belle processing facility located adjacent to the Kanowna Belle mine. The plant is designed to handle an estimated two-million tonnes a year of feed. It can treat refractory and free milling ores through the flotation circuit and associated concentrate roaster circuit, including carbon-in-leach (CIL) gold recovery, or bypass the flotation circuit and go directly to a CIL circuit that is designed to treat flotation tails.

The mine also has a mining fleet comprising boom jumbos, production drills, loaders, haul trucks, charge-up units, service vehicles and graders.

An office facility has been established in close proximity to the Rubicon openpit and comprises office workspaces, crib rooms, ablution facilities and communications tower.

Adjacent to the Raleigh openpit is the main stores area, light- and heavy-vehicle workshops that service the Rubicon, Hornet, Pegasus and Raleigh underground operations.

A core yard has been established at the old Kundana offices for processing, and the storing of exploration and underground drilling cores.

Laydown areas have been established around the mine site for temporary storage of equipment during normal mining and contractor operations. Each area comprise an open, compacted area of soil used for temporary outdoor storage.

There are no permanent structures or utility connections in these areas.

Prospects: Underground diamond drilling resource definition programmes have been completed at Millennium, Pope John, Moonbeam and Xmas deposits at the Kundana operation, with modest depth extensions identified at Millennium.

Contact Details:
Northern Star Resources
Tel +61 8 6188 2100
Email  info@nsrltd.com
Website https://www.nsrltd.com