The Tumpangpitu inferred resource has grown to 1.7 billion tonnes at 0.41% copper and 0.46 grams per tonne gold for 15 billion pounds of copper and 25 million ounces of gold, using a 0.2% copper cut-off grade.

The new resource incorporates drilling completed in the last six months since the previous estimate was released in May, but does not include five holes which are still awaiting logging and assaying.

The resource is based on a resource block model of around 3.4km by 2.8km with the vertical extent of mineralisation defined to date at around 1.1km.

Resources extend from 200-900m below sea level.

The updated porphyry resource is separate to the oxide resource of 130 million tonnes at 0.55gpt gold and 18gpt silver for 2.4Moz gold and 80Moz silver.

Intrepid has flagged further increases to the Tumpangpitu resource as drilling continues, suggesting it could be as much as 40-60% larger at a slightly reduced grade.

“While we are pleased to have tripled the size of this porphyry resource in just a little over a year, we still have not reached the limit of the resource at Tumpangpitu, let alone across the entire Tujuh Bukit project, which clearly ranks amongst the world’s major undeveloped copper-gold projects,” Intrepid chief executive Brad Gordon said.

“We will soon have 11 drill rigs available, including one capable of drilling to depths of almost two kilometres.

“We look forward to initiating drilling at the Salakan porphyry and continuing to expand our exploration program across this exciting project area.”

Last month, the company confirmed Candrian as the third porphyry system discovered at Tujuh Bukit and drilling at Salakan will begin in the March quarter.

A prefeasibility study into the oxide resource is already underway and the company will begin a scoping study on the porphyry resources in the first half of next year.

Intrepid shares jumped 6.6% or A8.5c to $1.365 in Australia this morning.