By: Mining weekly

Harena says the agreement represents a potential opportunity, along with its Ampasindava project, in Madagascar, to further its ambition to participate in the US government’s critical minerals strategy efforts.

Under the terms of the exclusivity agreement, Harena says it will conduct detailed technical, legal and commercial due diligence on the assets, with a view to progressing toward a definitive transaction should the results meet the company’s strategic and investment criteria.

The company explains that there can be no certainty that the exclusivity agreement will result in Harena entering into a definitive agreement or completing a transaction, adding that any such transaction remains subject to the satisfactory completion of due diligence, internal approvals and the negotiation and execution of definitive documentation.

Harena notes that the assets are located within a well-established and highly regarded mining district in the county, an area known for its favourable geology, established mining infrastructure and supportive regulatory framework.

The company says the county actively supports the fast-tracking of drilling approvals and benefits from a significant skilled workforce base and established mining infrastructure.

The county currently contains over 3 000 mines and over 8 000 active mining claims, the most of any county in California.

The company says the assets are strategically located in close proximity to MP Material’s Mountain Pass mine, the only operating rare earths mine in North America.

Harena notes that MP Materials has recently received substantial US government funding to expand domestic rare earths processing capabilities, highlighting the strategic importance of securing reliable sources of heavy rare earths feedstock in the US.

Harena says it believes the assets offer a significant opportunity for the company to contribute to this critical feedstock.

Originally developed as a gold and silver operation, the assets were later drilled for uranium, with rare earths more recently identified at the site.

Based on highly encouraging historical drilling results, the company says these assets have the potential to be one of the highest-grade rare earth element (REE) exploration projects in the US, with clear scope for rapid advancement through modern mapping, sampling, trenching, geophysics and drilling.

Geology

Harena explains that historical exploration, including over 4 200 m of drilling, has demonstrated encouraging geological indicators, highlighting the assets’ potential to host economically significant rare earth mineralisation and uranium deposits.

The initial exploration work identified strong geological analogies with established intrusive-related uranium deposits, including the Bancroft district, in Canada, the Midnite mine, in the US, and the Rössing and Husab mines, in Namibia.

These similarities place the assets within the class of intrusion-related alaskite and pegmatite-hosted uranium systems, which are typically associated with large-tonnage potential, moderate average grades and continuity at depth and along strike, rather than narrow vein-style mineralisation.

Uranium mineralisation occurs primarily as uraninite, with reported historical drill intercepts including 30.3 m at 0.37% triuranium octoxide equivalent (U₃O₈e) and internal higher-grade zones of up to 10% U₃O₈e, hosted within leucogranitic to pegmatitic intrusive bodies.

Harena says more recent surface exploration has identified REE mineralisation associated with late-stage pegmatites, porphyritic felsic dykes and possible carbonatite-style intrusions.

Both light REEs (LREE) and heavy REEs (HREE) are present with an about 50:50 LREE:HREE ratio.

The company notes that grab samples have returned assays of up to about 2% total rare earth oxide (TREO), with portable X-ray fluorescence (pXRF) readings of 0.5% to 7.2% total REEs across multiple locations.

Elevated heavy rare earth values, including yttrium, dysprosium and gadolinium, with pXRF grades of about 0.5% to 1%, are notable in a global context.

Harena says the area remains largely underexplored and has never been exposed to a modern systematic exploration programme.

The company says it believes substantial upside exists as further technical work is undertaken.

“These assets represent an exciting opportunity for Harena to broaden its exposure to the international critical minerals exploration and development story.

“There are so many underexplored and under-realised deposits that need to be properly assessed and evaluated, and few are better located than these permits.

“In addition to the elevated ratios of rare earths within these deposits, the uranium grades are in the order of 10 times some of those currently being mined around the world,” says Harena executive technical director Allan Mulligan.

“We are pleased to be entering into an exclusive period to consider these critical mineral permits in the US. The assets have already delivered strong results for heavy rare earths and uranium and are located within one of California’s most established and prospective mining districts.

“The US is at the forefront of addressing global critical mineral and rare earth supply bottlenecks and these permits represent another opportunity for us to support that effort,” adds Harena executive chairperson Ivan Murphy.