A Meeka Metals’ mapping and sampling program has highlighted what it believes is an important gold-arsenic anomaly within a 2km-long shear zone at its Murchison gold project, about 28km north-east of Meekatharra in Western Australia.
Management says its surface geochemistry picked up the anomalism, which mapping shows as correlating with en echelon splays where previous drilling intersected grades of up to 54 grams per tonne gold.
The splays occur within an intensely-sheared mafic central unit in association with the 2km-long north-west/south-east-trending Bunarra shear zone in the narrowing southern part of the Archaean Gnaweeda greenstone belt, where abundant evidence of historic mining includes old mine shafts and underground mining.
Previous third-party, shallow drilling in the vicinity of one old shaft picked up good grades in an intercept of 8m at 21.99g/t gold from 114m, including 4m going a healthy 39.8g/t. Another nearby drillhole jagged 1.6m at 27.8g/t gold and 1m running 54g/t, while three other holes in the area reported 6m at 5.95g/t, 6m at 2.65g/t and 3m at 4.1g/t.
Meeka Metals managing director Tim Davidson said: “The new information and interpretation suggest en echelon splays and structural low-pressure zones are the principal host of gold at Bunarra. We are now working to define the northern and southern extents of this shear zone, gather follow up samples and finalise drill planning to test new targets.”
The company’s latest geological mapping indicates that the multiple splays at the site are likely low-pressure responses to movement along the 2km-long shear structure and are the principal hosts to gold mineralisation that has not been previously tested in detail.
The greater significance of the anomalism may be that it lies just 18km south of Meeka’s flagship Turnberry deposit where the company has defined a mineral resource containing 685,000 gold ounces and averaging 2g/t. Moreover, it lies only 12km south of Meeka’s St Anne’s 25,000-ounce gold mineral resource.
Both Turnberry and St Anne’s are associated closely with similar north-west/south-east-trending shears that regularly cross the entire greenstone belt, which remains a consistent 6km-to-8km wide for much of its length.
It is only in the current southern area of sampling that the belt narrows and splits into narrow trends and tails out – and where a higher degree of gold host rock shearing might be expected. That seems to be indicated by the intensely-sheared gold host that contains fine gold inclusions within arsenopyrite and pyrite in a mineral assemblage made up of those minerals, in addition to quartz and tourmaline.
Meeka has put together an impressive total of 1.2 million ounces of gold in its 281-square-kilometre, 100 per cent owned Murchison gold project. It includes Turnberry where late last year it reported intersecting 19m at 8.75g/t gold in infill drilling.
The company is now pressing on with the development of Turnberry and St Anne’s and updating its grade-control block models for initial open-pit mining.
With its almost exclusive coverage of the northern and eastern parts of the Gnaweeda-Meekatharra-Wydgee greenstone system and a growing understanding of the structural mechanisms controlling potentially additional high-grade gold mineralisation, Meeka has both targets and space to continue significant further growth.
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