High-resolution drone magnetometer data collected in September and processed by the company's geophysical consultants defined the anomaly, which coincides with an induced polarisation (IP) chargeability response. The geological case is bolstered by the nearby Cousin Jack discovery, northwest of the new anomaly, where magnetic pyrrhotite, an iron sulphide, occurs with zinc, lead, copper, silver and gold mineralisation. The company says the undrilled anomaly may host a similar sulphide assemblage: its magnetic response could reflect pyrrhotite, while the coincident IP response may point to disseminated sulphides. Drilling will be needed to establish whether mineralisation is present and determine its nature and scale.
Lewis Ponds lies 15km east of Orange and covers 148 square kilometres in the Lachlan Fold Belt, a mining precinct that hosts tier-one deposits including Newmont's Cadia copper-gold mine. The project hosts a JORC-compliant resource of 17.52 million tonnes grading 1.12g/t gold, 53.34g/t silver, 2.06 per cent zinc, 1.10 per cent lead and 0.14 per cent copper, comprising 9.09 million tonnes in the indicated category and 8.43 million tonnes inferred. A scoping study released earlier this year outlined a base-case pre-tax net present value of $481 million for a staged open-pit and underground operation, and the company is advancing the project towards a prefeasibility study.
Previous drilling at Cousin Jack intersected broad polymetallic zones, including a 79-metre interval at 1.3 per cent zinc equivalent from 311m, an 86-metre interval at 0.6 per cent zinc equivalent from 408m and a 104-metre interval at 1.3 per cent zinc equivalent from 527m. The discovery sits 350m southeast of the existing resource area, within a broader nine-kilometre mineralised trend.
Orbit's diamond drilling program at Lewis Ponds has been testing the existing resource and exploration targets, with three holes totalling 1168.8m completed and a final 300-metre hole underway to test Spicer's Lode in the north of the deposit. Assays from that campaign are pending.
Managing director Jeneta Owens said: "The identification of a coherent 1km magnetic target immediately along strike from our Cousin Jack discovery is an exciting development. With drilling near completion and assays pending, the addition of a new magnetic target provides our investors with several encouraging near-term milestones as we look to unlock the full value of the Lewis Ponds asset."
The company plans to investigate the anomaly on the ground, looking for surface evidence that could link the geophysical response to the sulphide mineralisation at Cousin Jack, and will follow with a ground electromagnetic survey ahead of potential drilling. The findings tap into NSW's push to develop critical minerals, with copper and silver both among the five priority metals named in the state's Critical Minerals and High-Tech Metals Strategy 2024-35.