Australia

Mt Morgans Operation

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Overview

Mine TypeStockpile
Commodities
  • Gold
Mining Method
  • Truck & Shovel / Loader
Production Start... Lock
ShapshotMt Morgans Gold Operation comprises a CIL treatment plant, the Jupiter open pit and Westralia underground mining areas.

Open pit mining operations at Jupiter were suspended at the end of June 2022. Underground mining was completed during the September quarter.

The dominant source of ore feed to the processing plant during the FY2023 year was from low grade stockpiles with additional feed being sourced from the final harvesting of ore from Westralia underground mines.

In March 2023 the Dacian Gold announced completion of the transition from operations to explorer/developer with the processing plant and surrounding infrastructure placed on care and maintenance.

On 4 October 2023, the Dacian Gold announced that it was focused on developing a low risk, sustainable mine plan to enable a resumption of operations at its Mt Morgans Project.

Genesis Minerals is in preliminary discussions with Dacian in relation to the potential future re-start of Jupiter open pit.
Related Asset

Owners

SourceSource
CompanyInterestOwnership
Genesis Minerals Ltd. 95.1 % Indirect
Dacian holds a 100% interest in Mt Morgans Gold Operation through a combination of wholly owned tenure and those held by its wholly owned subsidiary, Mt Morgans WA Mining Pty Ltd.

On 16 October 2023, Genesis Minerals Limited released its Bidder’s Statement in relation to a conditional off-market takeover offer by Genesis to acquire all the shares in Dacian Gold Limited it does not own (Offer).

At the time the Offer was made, Genesis held 80.08% of Dacian Shares and controlled Dacian. As at the Last Practicable Date (October 30, 2023), Genesis has a Relevant Interest in 95.1% of all Dacian Shares.

The Offer is scheduled to close on 17 November 2023 unless extended.

Deposit type

  • Banded iron formation hosted
  • Vein / narrow vein
  • Mesothermal
  • Intrusion related

Summary:

Mt Morgans Gold Operation (MMGO) is located within the Eastern Goldfields of the Archaean Yilgarn Craton and covers a portion of the highly gold prospective Laverton Tectonic Zone (LTZ). Within the LTZ, the Laverton Greenstone Belt (LGB) is bounded by the granitoids of the Laverton Dome to the northwest and the Kirgella Dome to the southeast and by the north-northwest trending Mt Celia and Burtville faults. The geology of the LGB is generally poorly exposed, deeply weathered and extensively covered by Tertiary laterite. Recent sediments are extensive, particularly adjacent to the Lake Carey salt-lake system, which is situated to immediately south of the MMGO.

The stratigraphy of the MMGO is dominated by mafic volcanic (mostly massive tholeiitic basalt), mafic intrusive, minor ultramafic and metasedimentary units, as well as a narrow band (width <80m) of regionally continuous BIF. This package has been intruded by concordant and discordant felsic porphyritic dykes and sills. All lithologies were subject to regional scale greenschist facies metamorphism.

The MMGO lies in the overturned western limb of the Mt Margaret anticline which plunges moderately to the south and has a north-northwest trending fold axis.

There are a number of mineralisation styles identified at MMGO, including:
- BIF hosted deposits characterised by large tonnage, moderate-high grade such as Westralia and Morgans North have yielded the bulk of the gold won from the camp. The sulphide replacements occur both sub-parallel to BIF layering and also in en-echelon tensional veins oblique to layering.
- Syenite hosted/associated deposits - large tonnage, moderate to high grade such as Jupiter and the third party owned Wallaby deposit.
- Mafic hosted deposits and exploration targets - characterised by narrow high-grade veins and vein arrays such as at Transvaal, Ramornie, and Craic. The lodes may be stacked across strike, such as at Transvaal. Alteration comprises sericite-ankerite-pyrite with local biotite in well-foliated zones. Veins are quartz-dominated and contain carbonate and pyrite with trace sphalerite, chalcopyrite and galena. Vein style varies from brecciated to weakly laminated.
- Exploration Targets associated with late Archaean basin sediments.

Summary of the main deposits at MMGO
Westralia
The Westralia gold deposits (Beresford, Allanson, Millionaires and Morgans North) lie on the overturned western limb of the south plunging Mt Margaret Anticline. Westralia is divided into three components extending over a 3 km of strike, the Beresford Underground located under the Westralia and Millionaires open pit, the Allanson Underground lying between the Westralia and Morgans North open pits and the Morgans North open pit. Gold mineralisation is hosted within laterally continuous BIF (with lesser mineralised basalt, porphyry and ultramafic units), within a mine sequence comprising BIF, intermediate to mafic volcanics and ultramafic flows. The deposit consists of sub-vertical to steeply dipping stratigraphically continuous BIF with parallel and cross-cutting shear zones. Mineralisation is mostly confined to microscopic quartz-carbonate veinlets within the BIFs in area influenced by shearing. Gold occurred as free fine grains in; quartz-Fe-carbonate veins; along fractures in and between magnetite grains; as inclusions and late fracture fill in pyrite; attached to or as inclusions in chalcopyrite; and as inclusions in sphalerite. The Westralia resource area extends over a southeast-northwest strike length of 2.2 km, has a maximum width of 130 m and to a 1,280 m depth.

Phoenix Ridge
Phoenix Ridge is a BIF hosted underground deposit located to north-northwest of the Westralia open-cut within the same stratigraphic sequence as the Beresford and Allanson underground deposits. The deposit consists of sub-vertical to steeply south dipping BIF units within a shear zone. Mineralisation is characterised by pyrite and/or pyrrhotite replacement of magnetite within the BIF host while high grade mineralisation is structurally controlled by the interaction of both steep east-southeast dipping and shallow east dipping shears and faults.

Ramornie - Transvaal
The Ramornie-Transvaal deposits occur primarily within meta-basalt host rocks intruded by meta-quartz feldspar porphyry dykes. Gold mineralisation is hosted within north-northeast trending shear-hosted lodes, which form the extension of the Ramornie Transvaal Shear Zone. The mineralisation is contained mostly within metabasalt, with some gold mineralisation transgressing into the porphyries. The major structures at Transvaal consist of the north-northeast, steeply east dipping mineralised shears and a northerly dipping, post-ore thrust fault the Johannesburg Fault. The Johannesburg Fault dips at 30° to the north and displaces both the porphyry dykes and the mineralisation sinistrally. Quartz-rich veins are commonly associated with high grade mineralisation and are parallel with foliation, with some visible gold observed. The strike length of the major individual lodes averages 230 m and the strike length of the entire deposit is approximately 830 m.

Morgans North
The deposit consists of sub-vertical to steeply south dipping BIF units within a shear zone. Mineralisation is mostly confined to the BIF units. The Mineral Resource area extends over an east-west strike length of 640 m, has a maximum width of 40 m and spans a vertical extent of 200 m from 450 mRL to 250 mRL.

Jupiter
A structurally controlled mesothermal gold deposit related to sub-vertical syenite intrusions with cross-cutting, east and north dipping lodes within altered basalt and dolerites. Similar to the nearby third party owned Wallaby deposit but comprises three main syenite intrusive bodies, from south to north known as Ganymede, Heffernans and Doublejay lying within the Jupiter Corridor, defined by a 2 km long north-south trend. Most mineralisation is associated with shallow east-dipping shears as they cross-cut the syenite intrusions or altered basalts in proximity to these intrusions. Small number of variably oriented shears, faults and veins. The Mineral Resource area extends over a 2,080 m strike length and includes the 800 m vertical from 500 mRL to -300 mRL.

Mt Marven
Mt Marven comprises a series of lodes striking north and dipping moderately (60° to 75°) along the Mt Margaret Shear. Mineralisation is associated with haematite alteration, vein quartz, silica and coarse pyrite in a sinistral jog in the Mt Marven shear. Contacts between basalt and porphyry intrusive often mineralised. The Mineral Resource area extends over a 750 strike length and includes the 275 vertical from 475 mRL to 200 mRL.

Craic
Craic consists of a shear zone hosted high grade lode characterised by silicification and gold-bearing quartz veins. Primary lithologies are sheared and altered metabasalts with the style of mineralisation similar to that at Transvaal. The deposit is crosscut at an oblique angle by numerous moderate dipping quartz-feldspar porphyries. The thicker porphyries are barren, however the thinner porphyries may be sheared and mineralised. The stratigraphy is also cut by narrow, high grade subvertical lodes plunging to the north.

Maxwells
Gold mineralisation occurs within sub-vertical to steeply south dipping BIF units within a shear zone extending over a mineralised strike length of 1 km. Gold is restricted to the BIF in particular those within the regolith profile (however bedrock mineralisation is also developed). Thicker, higher grade zones occur at intersection of high strain zones with BIF and within associated quartz veins. Anomalous assays associated with unaltered BIF, Carbonate or haematite altered bands, low sulphides (<25.0% pyrite replacement), regularly banded and strongly fractured BIF. The Mineral Resource area extends over an east-west strike length of 640 m, has a maximum vertical width of 40 m and spans

Reserves

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Mining Methods

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Comminution

Crushers and Mills

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Processing

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Production

CommodityUnits202320222021202020192018
Gold koz  ....  Subscribe  ....  Subscribe  ....  Subscribe  ....  Subscribe13934
All production numbers are expressed as metal in doré.

Operational metrics

Metrics202320222021202020192018
Ore tonnes mined  ....  Subscribe  ....  Subscribe  ....  Subscribe  ....  Subscribe2,834 kt
Tonnes milled  ....  Subscribe  ....  Subscribe  ....  Subscribe  ....  Subscribe2,664 kt
Annual processing capacity  ....  Subscribe  ....  Subscribe  ....  Subscribe  ....  Subscribe2.5 Mt2.5 Mt
Waste  ....  Subscribe  ....  Subscribe  ....  Subscribe  ....  Subscribe8.3 Mbcm
Total tonnes mined  ....  Subscribe  ....  Subscribe  ....  Subscribe  ....  Subscribe

Production Costs

Commodity2023202220212020
All-in sustaining costs (AISC) Gold  ....  Subscribe  ....  Subscribe  ....  Subscribe  ....  Subscribe

Financials

Units202320222021202020192018
Revenue M AUD  ....  Subscribe  ....  Subscribe  ....  Subscribe  ....  Subscribe 132.8   1.4  
Gross profit M AUD  ....  Subscribe  ....  Subscribe  ....  Subscribe  ....  Subscribe 23.9  
Pre-tax Income M AUD  ....  Subscribe  ....  Subscribe  ....  Subscribe  ....  Subscribe -1.3   -32.9  
After-tax Income M AUD  ....  Subscribe  ....  Subscribe  ....  Subscribe  ....  Subscribe 3   -5.4  
EBITDA M AUD  ....  Subscribe  ....  Subscribe  ....  Subscribe  ....  Subscribe 20   33.5  
Operating Cash Flow M AUD  ....  Subscribe  ....  Subscribe  ....  Subscribe  ....  Subscribe 47.2   17.5  

Heavy Mobile Equipment

Fleet data has not been reported.

Personnel

Mine Management

Job TitleNameProfileRef. Date
....................... Subscription required ....................... Subscription required Subscription required Nov 8, 2023
....................... Subscription required ....................... Subscription required Subscription required Nov 8, 2023
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Aerial view:

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