Andy Well Mining Pty Ltd, a subsidiary of Meeka Metals Limited, owns 100% of all Exploration Licenses, Mining Leases and mineral rights for the Murchison Project.
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Summary:
The Murchison Project compromises two open pit (St Anne’s, Turnberry) mining centres and two underground (Turnberry, Andy Well) mines.
Andy Well
Andy Well is located at the northernmost end of the north-north easterly trending Archaean Meekatharra-Wydgee greenstone belt, within the Youanmi Terrane. The belt comprises a succession of metamorphosed mafic to ultramafics, felsic and sedimentary rocks interpreted to belong to the Norie Group formerly Luke Creek and Mount Farmer Groups.
The mineralisation at Andy Well is orogenic shear hosted, in narrow high-grade quartz reefs. Economic mineralisation has so far been identified within five parallel northnortheast trending quartz reefs; Wilber, Judy North, Judy South, Suzie and Jenny.
The Wilber Shear is a 2-5m intensely sheared zone within a broader 20-60m wide zone of foliation. The shear dips 80°-295° with an early foliation S1, dipping 84-90° - 108-114°, overprinted by a penetrative S2 foliation that dips on average 80°-295°. Kinematic indicators inside the shear zone suggest it is dominated by combined reverse-sinistral movement. Younger fold and crenulation cleavage events have little impact on the quartz reef and shear zone. Minor normal block faulting offsets the reef in some areas <5m. The dominant sinistral-reverse movement observed in the Wilber Shear zone is permissive for Wilber being an extension shear vein or riedel shear opening.
The Wilber Shear is one of several similar sub-parallel northeast-southwest shear structures approximately 200m apart. A north-south structure orientation is also evident in magnetic images and appears to have dextrally offset northeast-southwest structures in places by up to 100m. The north-south structures appear to define the northern and southern strike extents of the lodes and dextrally offset the northeast-southwest shears.
Historical production was principally sourced from the Wilber lode, a sub-vertical slightly west dipping laminated quartz vein commonly 0.4 to 1.5m in width with a well-developed boudinage texture. The lode forms an extensive and largely continuous sheet of mineralisation, which is currently defined over 600m strike and 700m down dip, remaining open at depth.
Dimensions
The Wilber resource extends for 845m in strike length, from 4m below surface to 1,000m below surface, and averages 1 meter true thickness, average 80° dip to the west.
The Judy resource strikes 900m and extends from surface down to 800m below surface, averaging 0.5m to 1.0m true thickness and dipping approximately 80° to the west.
The Suzie resource extends for 500m along strike from surface down to 500m below surface, averaging 0.5m to 1.0m true thickness and dips approximately 70° to the west.
Turnberry
Turnberry is located within the Gnaweeda greenstone belt, a narrow belt of Archaean volcano-sedimentary rocks up to 10 kilometres wide in the northern half and decreasing to less than one kilometre in the south, situated at the northernmost margin between the Achaean Murchison, Southern Cross, and Yeelirrie Provinces.
The area is covered with transported colluvium to a depth of ~10-25m and is highly weathered with a depth to fresh rock of ~100m.
Mineralisation forms a 1.7km north-northeast trending gold anomalous corridor, which is broadly defined into three zones, Turnberry South, Central and North. Mineralisation is primarily hosted where shears intersect fold hinges (saddles) and limbs of felsic lithological boundaries. Vein and shear-hosted mineralisation are also present at the mafic contact, which tends to host narrow, high-grade gold. In other areas (e.g. outside of fold hinges or lithological contacts), gold mineralisation is controlled by the orientation of steeply, dipping veins within the shear zone.
Mineralisation can often be visually indistinct owing to several styles of mineralisation being present and manifested differently depending on the lithology of the host rock. There are several unrelated shearing and veining events, however gold is usually accompanied by an increase in disseminated pyrite.
Mineralisation at Turnberry South and Turnberry North has developed within felsic volcanics and porphyries with strong pervasive sericite-pyrite alteration, which hosts broad low grade gold mineralisation and local sporadic high grades. Vein and shear mineralisation is also present at the mafic contact which tends to host narrow, high grades with occasional visible gold in RC chips.
At Turnberry Central, gold is hosted within a broad alteration zone within a quartz dolerite unit. Gold is believed to occur on the flanks of an intense silica-albite-pyrite ‘core’ surrounded by distal chlorite and epidote alteration. Gold is associated with disseminated pyrite, which occurs at a background level of around 1% in un-mineralised magnetic dolerite and increases to up to 30% within the centre of the alteration zone. Gold bearing alteration is typically associated with 3-10% disseminated pyrite with moderate chloritemagnetite+silica alteration and can occur on either side of the core of the altered zone.
Dimensions
The Mineral Resource extends over 1.7km strike and from ~10m to ~500m below surface. It remains open at depth. This proxy considers the lithology host, the alteration intensity, and the structural orientation. The mineralised wireframes vary between ~1 m and ~20 m in width.
St Anne’s
St Anne’s is located centrally within the north-south trending Archaean Gnaweeda greenstone belt. At St Anne’s, the belt comprises a succession of metamorphosed mafic to ultramafic, felsic and metasedimentary rocks with minor felsic to intermediate intrusives interpreted to belong to the Norie Group, formerly Luke Creek, within the Murchison Supergroup.
The St Anne’s area is covered with transported colluvium to a depth of ~20m and is highly weathered with a depth to fresh rock of ~100 to 160m.
Mineralisation at St Anne’s forms an 800m north-northeast trending gold anomalous corridor, which occurs within a broad alteration zone logged by geologists and mapped by arsenic anomalism in pXRF analysis. Mineralisation is widespread and occurs within multiple mineralised envelopes, predominantly concentrated within the mafic rocks proximal to lithology contacts.
Dimensions
The Mineral Resource extends over 550m strike and from ~20m to ~90m below surface. It remains open at depth. These extents host 9 modelled mineralised wireframes, interpreted as a proxy for the mineralisation. This proxy considers the lithology host, the alteration intensity, the presence of high value arsenic (associated with arsenopyrite) and the structural orientation. The mineralised wireframes vary between ~1 m and ~13 m in width.