Sunstone Metals (ASX:STM) has drilled just two holes at its Bramaderos Main copper-gold play in Ecuador, but it thinks it may have a system measuring 300m below surface to more than 500m laterally.

It told its shareholders this morning that it had received results from the first hole drilled at the project, and the top 200m of a second hole.

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The high-grade zones include down hole widths of up to 97m at 0.61 grams per tonne (g/t) gold and 0.18 per cent copper from 39.9m in its first hole.

Sunstone said the early results combined with trenching work meant that the higher grade zones could be mapped at surface — with at least three able to be seen from surface in early exploration datasets.

The company will now drill more to try and define the lateral definition of the porphyry system, and managing director Malcolm Norris thinks the system could be a big one.

Most of the major copper deposits around the world are porphyry deposits. They are usually large and low-grade but can be mined at low cost due to their scale.

Porphyries typically range from 100 million to 5 billion tonnes, but at lower grades of between 0.2 per cent and less than 1 per cent copper.

“Target areas are becoming clearer as we complete more drilling,” Norris said.

“We’ve only drilled two holes, but we can already see clear opportunity for a sizeable copper-gold system extending from surface outcrop to at least 300m below surface, and with opportunity to extend laterally by in excess of 500m.”

In other ASX base metals news:

After 18 and a half years, there’s changes afoot at Panoramic Resources (ASX:PAN) with managing director Peter Harold to step down. While his tenure is set to run out next year, this could be brought forward if Panoramic is successful in finding a suitable replacement before then. Harold took the junior explorer from a $3m IPO to a company with a market cap of over $200m and a nickel mine that is set to start producing during the December quarter this year.

In between, it acquired the Lanfranchi nickel mine in Kambalda which produced 190,000 tonnes of nickel, 53,000 tonnes of copper and 5000 tonnes of cobalt over 12 years. Harold also oversaw the pay out of $114m in fully-franked dividends in his time, and with Savannah about to start producing the company decided it was time for a re-fresh.

Chalice Gold Mines (ASX:CHN) has found “several highly prospective EM conductors” as part of a moving loop electromagnetic (EM) survey completed on its King Leopold nickel sulphide project. The project, which is right next to a JV between Buxton Resources (ASX:BUX) and Independence Group (ASX:IG) in the Kimberley, is home to a cluster of “stong, discrete, late-time EM conductors” at its Ephesus prospect and a new strong, discrete EM conductor at its King Sound prospect.

It all means that Chalice will have more targets to chew on, with a drilling program already set out to test two Ephesus targets and potentially additional targets at King Sound. The drilling will take place next month, with Chalice managing director Alex Dorsch telling the market that the Ephesus target is especially interesting. “Ground-based EM surveys have confirmed several strong, shallow EM targets at Ephesus which, considering their proximity to the high-grade Merlin nickel sulphide prospect, may represent massive sulphides,” he said.