Novo’s Egina project lies in the heart of the Pilbara conglomerate gold province approximately 120 km east of Novo’s Karratha gold project. Upon recognizing its conglomerate gold potential, Novo began applying for multiple exploration licenses covering much of the core area beginning in 2017. In September 2018, Novo announced two transactions; the acquisition of private company Farno-McMahon Pty Ltd (“FM”), and a joint venture with ASX-listed Pioneer Resources Limited, increasing Novo’s Egina project to 948 square km. Importantly, purchase of FM included granted mining leases M47/560 and M47/561 covering approximately 11.8 square km of key target areas. The farm-in and joint venture with Pioneer was finalized in September 2018 and the acquisition of FM was finalized in October 2018.
Like Novo's Karratha gold project, Egina is an important part of the Pilbara conglomerate gold province. Not only does Egina have potential to host significant deposits of gold-bearing conglomerates, weathering and erosion appear to have liberated considerable gold from these rocks and redeposited it into extensive surficial lag gravel deposits blanketing much of the area. Gold-bearing gravels can easily be explored as described in Novo's aggressive exploration program described below.
Egina Exploration Model Highlights:
- Three styles of gold mineralization are recognized at Egina: 1) basal Fortescue gold-bearing conglomerates like those at Novo’s Karratha gold project, 2) gold-bearing, deflationary and/or marine lag gravels blanketing an erosional terrace covering most of the Egina area, and 3) lode gold mineralization hosted by the underlying Mallina Basin assemblage.
- Given the large size of the target, Novo considers the gold-bearing terrace lag gravels to be the most important immediate target at Egina. Gravel deposits form a continuous sheet across much of the terrace. Where they have been trenched, they are up to 1.5 meters thick and weakly consolidated. Lag gravels rest on weathered Mallina Group sedimentary rocks, and up to 1 meter of soil and sand overlie them.
- Novo has discovered considerable cobbles and boulders of weathered Fortescue-type conglomerate within the lag gravels. Particulate gold has been observed in the matrix of some conglomerate boulders. A few gold nuggets that have been recovered from trenches at Egina remain partially encased in ferruginous rock matrix, some of which display a distinctive melon seed shape similar to nuggets observed at Karratha. Remarkably, halos of fine-grained gold are evident in the residual rock matrix surrounding these nuggets, again strikingly similar to that observed around in situ nuggets at Karratha. Novo firmly believes much of the gold in lag gravels is derived from geologically recent weathering and erosion of Fortescue-type conglomerates that once blanketed this area.
- Most gold found at Egina is coarse and water-worn. During the 2018 exploration season, FM focused entirely on metal detecting nuggets within a series of trenches covering an area roughly 500 x 200 meters. Detected nuggets range in size from approximately 0.5-104 grams. As a test for the presence of fine-grained gold, Novo recently assessed gravel from these trenches. Significant numbers of small nuggets up to 4 mm across were recovered along with appreciable very fine gold particles down to approximately 10 microns in size. Novo finds the presence of fine gold particularly encouraging and believes it may be derived, in part, from weathering of halo gold associated with Fortescue-type nuggets.
2018/2019 Exploration Plans
- Systematic sampling of
- largely unworked areas of lag gravel within M47/560
- gravels already excavated but not processed by FM that have shown appreciable fine gold in preliminary testing
- Geophysical testwork including ground penetrating radar and ground magnetics to define terrace and channel geometries
- Trench mapping and survey pickup to delineate gravel horizons for input into a 3D model
- Conduct broader-spaced program of alluvial sampling for fine gold and develop coarse gold assessment strategy
- Assess Novo’s IGR3000 alluvial processing plant for suitability and engineering modifications ahead of bulk sampling of the terrace gravels in 2019
- Regional 1:2,500 scale mapping to define areas of conglomerate gold and basement gold potential
Novo plans to engage the Kariyarra and Mugarinya Traditional Owner Groups to seek permission to explore on Novo-controlled exploration licenses surrounding M47/560. Environmental regulators will also be engaged regarding permitting requirements for the project, laying the groundwork for Novo to conduct test mining of lag gravels on mining lease M47/560 at Egina beginning after the rainy season, approximately second quarter of calendar 2019.
Sampling Update (January 2019)
A total of 107.88 grams of raw gold were recovered from 95 cubic meters of gravel. Gold was found to be dominantly coarse suggesting simple processing techniques can likely be employed during potential future large-scale gold recovery at Egina. Novo thinks lag gravels mantling the vast erosional terrace at Egina could host a significant gold deposit, the shallow nature of which makes it a particularly attractive target.
Work at Egina is on hold during the rainy season lasting until late March, 2019. Plans are currently being made to resume aggressive bulk sampling and processing on the Egina mining lease to evaluate the geologic potential of the terrace gravels as well the best means of processing. Current permitting allows for up to 50,000 tonnes of gravel to be excavated and processed at Egina, subject to appropriate heritage clearances.