Estrella Resources’ initial trial of induced polarisation (IP) technology at its manganese prospects in Timor-Leste (formally East Timor) has proved highly responsive and marks a significant step forward in the company’s ability to correctly identify supergene mineralisation.
The trial was designed to run a survey line across ground that Estrella could clearly see was likely to host supergene mineralisation. By pairing the results with visual observations, the company then confirmed the exploration method as valid.
To put the electromagnetic survey properly through its paces, Estrella’s field operatives conducted trials at two different concessions.
The first test was run across ground at its newly acquired Samalari prospect, directly south of the regional capital of Bacau. The second trial was shot at its northernmost Sica prospect.
Both prospects form part of the manganese-hosting Noni formation.
Estrella’s geologists also looked for differing responses to supergene manganese mineralisation in each area depending on localised geology.
The Sica survey - although producing a weaker signal - was still able to pick up anomalies sitting beneath the localised Baucau limestone cover. No such issues were encountered at the southern Samalari prospects.
The chargeability response in the clays in the weathered zones at both sites was too weak and too fast to get reliable feedback.
However, Estrella believes an easy fix to the problem would be to replace the 12-volt battery as the power source with a small generator, allowing more power to be pumped into the ground.
Although Estrella believes further work is still required to finetune the process, the eventual plan will be to systematically apply IP across all its licences to build an exploration database to help unearth further discoveries.
Not only will IP prove to be a critical exploration tool going forward, the “FlashRes Universal 64” IP system being used is highly transportable and extremely robust in the field, which is an important factor in Timor Leste’s tropical climate.
Estrella managing director Chris Daws said: “These IP trials give Estrella its first look at potential manganese discoveries at depth. Timor-Leste is virtually unexplored, so these findings are not just important for Estrella Resources but also relevant for the future of its developing minerals exploration industry. From the early work completed, we are very encouraged to be identifying low resistivity anomalies.”
Estrella employed eight local Timorese workers to transport kit to site and set up the IP lines as part of its community engagement commitment. The company also partnered with the National University of Timor-Leste to involve two geophysics students in the trial process, providing hands-on experience, from equipment setup to data acquisition.
Building on the initial success of its IP program, Estrella is moving the trial to some of its other prospects, including the Lalena and Ira Miri concessions it holds with joint-venture partner Murak Rai Timor (MRT).
The company is also converting its current environmental permit to a higher category, allowing it to start trenching work before eventually getting stuck into drilling next year.
As one of the first foreign companies to have secured mineral exploration licences in Timor-Leste, Estrella has an enviable head start on other explorers. If it can fine tune an IP system that works and finds manganese almost every time, the sky is the limit in this largely untouched mineral jurisdiction.
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By James Pearson
