Junior explorer Tambourah Metals has added the Neptune copper-gold project to its portfolio in Western Australia’s Bryah Basin.
The project sits 60 kilometres south-west of the high-grade DeGrussa and Horseshoe Lights volcanic-hosted massive sulphide (VHMS) copper-gold deposits.
It is nearby to numerous Proterozoic gold deposits including Fortnum, Horseshoe and Peak Hill and includes 5km of the Narracoota-Karalundi geological contact.
The contact is reported to be a regionally-important stratigraphic position for VHMS mineralisation.
Neptune prospects
The Neptune project includes the Neptune and Neptune East prospects which have historically returned significant copper-gold anomalies including 24 metres at 0.12% copper from 88m, 5m at 1.58 grams per tonne gold from 65m, 5m at 0.84g/t gold from 20m, 0m at 0.11% copper from 85m and 5m at 1.98g/t gold from 65m.
These anomalies are spatially associated with the interpreted contact position of Narracoota-Karalundi and are analogous to the interpreted stratigraphic position of the DeGrussa deposit.
Detailed review
Tambourah has planned a detailed review of historic exploration data relating to the Neptune and Neptune East prospects, noting that strong deformation within the tenement may potentially result in a short strike length and steep plunge of the targeted massive sulphides.
The company has also applied for additional tenure in the Bryah Basin which includes historic gold and base metal targets with a combined area of 218 sq km.
The tenure partially surrounds the 250,000-ounce Harmony gold mine and includes extensions to the upper Narracoota-Ravelstone contact that hosts the mineralisation at Harmony.
This contact is expected to become the focus for future exploration.
Bryah Basin exploration
Exploration within the Bryah Basin intensified following the discovery of the DeGrussa deposit in 2009.
Soil geochemistry defined a 2.5km-long anomaly which was tested with generally wide-spaced drilling, while another campaign at the Neptune prospect identified three sulphidic carbonaceous shale horizons within the upper Karalundi formation believed to be associated with moderate levels of copper and multi-elements.
Gold anomalies have also been associated with the overlying mafic Narracoota formation with zones of strong to intense sericite-chlorite plus silica.
Gold has proven to be an important vector to VHMS mineralisation at Bryah as Horseshoe Lights and DeGrussa are associated with gold enrichment and copper depletion in the overlying upper weathered zone.
