“Bulletin is a remarkably high-grade deposit that not only outcrops at surface but is more excitingly, completely open at depth. We will immediately mobilise a drill rig to undertake confirmatory drilling and commence testing the depth potential of the deposit,” Calidus managing director Dave Reeves said.

The maiden mineral resource at Bulletin totals 111,000oz.

The inferred resource comprises 832,000t at 4.1gpt and the preliminary pit optimisation indicates all-in sustaining costs at Bulletin of A$1300-$1600/oz, the company said.

Bulletin is one of four “high-priority” prospects in the historical Bamboo Creek mining centre, which produced over 220,000oz at 8.7gpt, Calidus said.

In September, Calidus remodeled its open pit options at its $120 million Warrawoona mine, cutting reserves by 26% from 517,000oz to 380,000oz.

The company originally targeted annual output of 80,000ozpa which was to ultimately rise to 130,000ozpa.

Over the seven-year plan, peak production is now 105,000ozpa in FY29. The Bulletin production is additional to the production profile.

The company’s share price gained 6.5% to 16.5c in midday trade, which capitalising Calidus at $100 million.

At September 30, the group’s cash and cash equivalents were $15 million following debt repayments of $6 million. That compares to $21.6 million at the end of June.