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The Eastern Goldfields of Western Australia: another of Australia’s great mineral provinces

Mt Zephyr is a section of greenstone belt localised on the Celia Lineament and located 60km NNE of Leonora.

Eastern Goldfields :

GOLD: Wallaby, Mt Morgans, Sunrise Dam, Kalgoorlie Super Pit, Sons of Gwalia, Kanowna Belle, Wiluna, Norseman, St Ives, Kundana

NICKEL: Mt Windarra, Mt Keith, Kambalda Murrin Murrin, KNP

Ardea’s Mt Zephyr Project contains both primary gold and nickel mineralisation and encapsulates more than two thirds of a little explored greenstone belt. The area east of Celia Lineament is considered highly prospective at Mt Zephyr for the following reasons:

Gale gold prospect

  • High-grade, extensive, shallow anomaly
  • Shallow RAB intercepts
  • Jupiter/Wallaby analogue, same host rocks
  • Jones Area A & B Nickel Sulphide Classic komatiite-hosted nickel features Mt Windarra analogue, same host rocks

Gale is a 273ppb Au soil anomaly which Aurora Gold¹ RAB drilled in the 1990s and intersected consistent >0.25g/t Au from surface to RAB refusal with intercepts of 6-18m at 0.5g/t Au and peak 6m at 1.3g/t Au. The anomaly is clearly a sub-horizontal geometry and not the narrow sub-vertical interpretation of previous explorers.

¹ Aurora Gold has not consented to the use of the historical geological report reference in this announcement. The potential quantity and grade of any mineralisation is conceptual in nature, there has been insufficient exploration to estimate a mineral resource and it is uncertain if further exploration will result in the estimation of a mineral resource.

The Gale RAB gold anomaly at a 0.25g/t Au cut-off grade defines an open sub-horizontal sheet with 700m N-S strike, 100m E-W width with up to 18m thick (corresponding to RAB refusal depths).

A site visit confirmed the anomaly has not been followed up with previous RC drilling, apart from a very limited program at the extreme northwest corner of the soil anomaly. Old RAB chips mixed with aeolian sand located at the old RAB collars returned consistent 0.1-0.4g/t Au. RAB chips included silica-pyrite-sericite alteration, which have the appearance of a “late stage mineraliser”. The geological expression of Gale is felt to be closely analogous to the Dacian Gold Jupiter syenite-hosted gold discovery, located 50km southeast along strike on the Celia Lineament.

The RAB chip anomalism is supported by up to 1.4 g/t Au in an “unaltered” granite float composite south of the RAB-drilled area, and 1.2-1.5g/t Au in gossanous limonite-white quartz vein float to the east of the RAB-drilled area.

The observed sub-horizontal RAB litho-geochemistry is a primary protolith attribute, since very clear-cut sharp barren RAB assays occur at the east and west contacts (if solely a supergene blanket enrichment, diffuse contacts with wider and more gradual dispersion would be expected).

Ardea plans to follow up the Gale RAB anomaly with systematic RC drill traverses.

Dunns Line of gold prospects

  • 4 km strike of mineralised BIF with old workings
  • Mt Morgan’s analogue, same host rocks
  • Mt Magnet Hill 50 “Boogardie Breaks” model

The model for gold mineralisation has been refined with the recognition that historic workings are closely associated with NE trending cross-faults within the N-S trending main BIF horizon. Ardea’s exploration model has evolved to be closely analogous to the Hill 50 “Boogardie Breaks” at Mt Magnet in Western Australia.

Rock chip and historic percussion drill chips along the target zone were sampled. It is planned to complete systematic soil auger geochemistry along the 4km of exposures along Dunns Line and extending into soil covered (altered) areas along strike of the main BIF.

Jones Area A and B nickel sulphide prospects

  • Classic komatiite-hosted nickel features
  • Mt Windarra analogue, same host rocks

Olivine adcumulate komatiite channel facies have been identified by Ardea within a stratigraphic horizon which is felt to correlate with the Mt Windarra nickel sulphide mine stratigraphy. A sulphide facies BIF underlies the komatiite channel at Jones A, which is an excellent setting for “Silver Swan-style” nickel sulphide occurrences. Ironstone assays by Ardea at Jones Area B returned 0.3% Ni, confirming a prospective nickel sulphide setting.

Soil auger geochemistry is planned ahead of ground EM surveys.

There has been no previous RC drill testing of the Jones targets.

The Mt Zephyr E39/1854 application containing the Gale, Dunns and Jones prospects has been recommended for grant and consultant retained for a heritage survey.