The stratigraphy covered by the KCGM tenements consists of a basal ultramafic unit called the Hannan Lake Serpentinite. This ultramafic unit is overlain successively by the high magnesian Devon Consols Basalt, Kapai Slate, tholeiitic Paringa Basalt and the Black Flag sediments. Differentiated zones of dolerite and gabbro texture occur within the mafic sequence. The Golden Mile Dolerite, hosting the bulk of the Golden Mile and Mount Charlotte gold mineralisation, is a strongly differentiated layered gabbro, approximately 700m in thickness. The Golden Mile Dolerite is situated conformably between the Paringa Basalt and the Black Flag sediments. This entire stratigraphic sequence is intruded by numerous porphyry dykes of intermediate to felsic composition.

The Mt Charlotte style gold mineralisation is hosted within the Golden Mile Dolerite and is predominantly associated with pyrite in carbonate alteration haloes around quartz veins, with a minor proportion as relatively coarse free gold within the veins, commonly close to their margins. The veins vary in width from a few millimetres to a maximum of about two metres but are commonly between two centimetres and 50 cm wide. The vein spacing varies from 20 cm to tens of metres but is typically from 50 cm to two metres in areas mined as ore. Quartz is the dominant vein-fill mineral; accessory vein minerals include calcite, ankerite, scheelite, pyrite, pyrrhotite, and gold.

The Hidden Secret style gold mineralisation is hosted within the Williamstown Dolerite at the contact with the Kapai Slate and Devon Consols Basalt and spatially associated with a porphyritic intrusion and the Towns Fault. Gold is hosted in deformed a quartz vein 2- 20cm wide. Vein minerals include pyrite, telluride, silica, carbonate and fuchsite.

Multiple drill programs were completed in FY2020 across various project areas at Mt Charlotte. Results are encouraging with more drilling planned in FY2021 as the full scale of the mineralised system and how it interacts with Fimiston is being modelled and tested. [Saracen, 2020, AR, p.20]

Mt Ferrum is a shear-hosted Fimiston-style lode located 600m east of the Sam Pearce decline of the Mt Charlotte mine. Mineralisation is hosted within Paringa Basalt and strikes NNE. Infill resource definition drilling has identified a series of hangingwall and footwall structures, and stockwork mineralisation in Williamstown Dolerite to the west of the main lode. Mineralisation is thought to be controlled by the structural architecture and is the subject of a geological review currently underway. [Saracen, 2020, AR, p.20]

Kal East is a narrow, high-grade Fimiston-style lode lying 250m to the east of existing infrastructure at the Mt Charlotte mine. Infill resource definition drilling has identified more complexity than expected, defining a series of hangingwall and footwall structures. Mineralisation is hosted primarily within Williamstown Dolerite and the highest grade is constrained within a steeply dipping southerly plunging shoot. Internal zones within the Williamstown Dolerite are important in controlling the distribution of gold. [Saracen, 2020, AR, p.20]

Belgravia is a series of mineralised lodes lying 100m north of existing infrastructure at the Mt Charlotte mine. Mineralisation is hosted within pillowed and variolitic Devon Consols Basalt in proximity to the Hannans Lake Serpentinite, the contact of which is intruded by felsic porphyritic rocks. Infill resource definition drilling has identified eight separate NNW- striking lodes with en échelon geometry. The lodes are overprinted by stockwork mineralisation, with veins dipping to the north similar to the Mt Charlotte-style stockwork orientations. [Saracen, 2020, AR, p.20]

Mt Charlotte Underground Mine
The main historical method of mining at Mt Charlotte was open stoping. Typically, large stable open stopes were mined and then the rib/crown pillars were mass blasted, with waste rock fill above cascading onto the broken ore.

The Mount Charlotte underground mine is accessed via a portal Sam Pearce decline within the Fimiston Open Pit. Production in Mount Charlotte is carried out utilising a combination of remnant Sublevel caving, modified Avoca and conventional longhole open stoping. Where possible, stopes are backfilled with development waste to save haulage costs.

Currently stoping under rock fill (SURF) is used to recover remnant resources. Extraction is from drawpoints until waste rock dilution becomes excessive. Ore from Mt Charlotte is transported to the Fimiston Plant via the Sam Pearce Decline. The underground stopes are backfilled with either mine waste or crushed rock for stability purposes. Fill is delivered through the Glory Hole. Development of the Hidden Secret deposit located 400m east of Mt Charlotte commenced during 2016. Planned stope extraction will utilise the modified Avoca method.

Overland Conveyor
A conveyor previously used to transport ore has been reversed and is now used to convey waste rock from the Fimiston Operational Area to the Glory Hole for underground fill. The conveyor passes under Boorara Road and over Williamstown Road. An unsealed access road is in place along the length of the conveyor.

The Mt Charlotte Underground Mine currently produces ore at the rate of 1.15M tonnes per annum (tpa) which is transported directly to the ROM at the Fimiston Plant via the Sam Pearce decline located within the Fimiston Open Pit north eastern wall. Waste rock produced during mining at Mt Charlotte is not brought to the surface, instead it is used to backfill underground voids. Small volumes of waste rock from the Fimiston Open Pit are crushed at Fimiston before being conveyed to the ‘Glory Hole’ Pit to be used for backfilling of underground stopes at Mt Charlotte.

The ore from the Fimiston Open Pit and Mt Charlotte Underground Mine is processed at KCGM’s Fimiston and Gidji Processing Plants. The Fimiston and Gidji Processing Plants were commissioned in 1989.

The Fimiston Processing Plant operates in accordance with Prescribed Premises Licence L6420/1988/14 with an approved production capacity of 14,500,000 tonnes per year, whilst the Gidji Gold Processing Plant operates in accordance with Prescribed Premises Licence L5946/1988/13 with an approved production capacity of 438,000 tonnes per year.

The Crushing Services International (now CSI Mining Services) team crush raw material mined from Mt Charlotte and the open pit, where it then heads to the processing plant, or as waste to the Glory Hole. The team also supplies stemming material for the Blast Crew to use when backfilling blast holes and road base to sheet mine roads.

The Crushing Facilities and Stockpiles consist of contractor owned ‘secondary’ crushing fac ........