Rockfire Resources PLC's review of previous work at its Copperhead project in north Queensland, Australia, revealed a historical metal-content estimate of 56,000 tonnes of copper.

The historical resource is hosted in 35 million tonnes of ore at 0.16% copper, according to the July 2 release.

The company is planning an induced polarization geophysics program to help target potential extensions and high-grade zones, and a drilling program to verify and expand the historical drilling results to establish a mineral resource at Copperhead.

Rockfire noted that the estimate was calculated before introduction of the JORC code, and core sampling in 1988 lifted the average core grade to 0.25% copper.