GEOLOGICAL SETTING
The CSA deposit is one of several base metal- and Au-bearing deposits of the Cobar Mineral Field. It occurs on the E margin of the early Devonian Cobar Basin (Central Lachlan Orogen) and is hosted by the CSA Siltstone (turbiditic siltstones and sandstones). The CSA Siltstone (Glen, 1991) is part of the Cobar Supergroup, consisting of lower syn-rift sediments (Nurri Group) and upper post-rift sag phase sediments (Amphitheatre Group). These rocks have undergone lowergreenschist metamorphism.

The CSA deposit lies near the stratigraphic top of the CSA Siltstone (Glen, 1994). It is bound to the W by the Footwall Fault (Kappelle, 1970) and located immediately N of the WNW-trending Plug Tank Fault and W of a NNE-trending right lateral fault (Glen, 1988). Between these structures, ore zones occur as a series of N-trending, steeply E-dipping lenses within the W- dipping host sequence. The lenses are parallel to the regional, steeply E-dipping cleavage. Rocks enclosing the mineralization show extensive alteration. Green Fe-rich chlorite and silica are prominent alterations.

Minor gossans occur close to the CSA mineralization. Weathering commonly reaches 20-100 m. Strong oxidation reaches 60 m and moderate to weak oxidation penetrates to 100 m. Secondary hematite and goethite mottling extends from surface to 75 m. Deeper oxidation commonly extends to >100 m along faults and shears and to >160 m over the CSA deposit itself.

MINE ........

The mining method used at the CSA Mine for the majority of stoping remains as top down, continuous advance, long-hole open stoping. Most stopes to date have been filled with Cemented Hydraulic Fill (CHF) and the balance is filled with development waste, either as clean waste co disposal with CHF or as CRF. CHF has been phased out and replaced with Cemented Paste Backfill (CPB) commissioned July 2018 with full filter plant commissioning completed in November 2018. The majority of the QTS Nth stope sequences will be filled with CPB. Trials for the uses of the Modified AVOCA mining method have been undertaken to further increase opportunities to maximise waste disposal and allow mining of marginal mining areas. Modified AVOCA mining method will be used in mining the QTS Central and Western Orebody.

During 2021, underground horizontal development advancement totalled 5,515m. The primary focus was advancing the decline towards the 8465 level; the main decline position at end of year was 40m ahead of original budget position. This advance was completed along with continuing the 8500 and 8450 levels, production-related development in QTS North, and access development to establish mining in QTS Central and Western Zone, both commencing production in Q3 2021.

Mining is almost complete above the 8700 level in the QTS North, except for some already developed remnant material between 8850 - 8950. QTS South mining is complete above the 9015 level. The economic bottom ........

- subscription is required.

- subscription is required.