Big Hits: Haranga delivers US Mother Lode gold masterclass

Big Hits looks at notable drill hits reported to the ASX this week, led by Haranga Resources’ underground gold intersection with a blistering 32 metres at more than 10g/t gold in California. West Musgrave-focused runner-up Terra Metals landed a massive, near-surface PGE broadside exceeding 190 metres of continuous shallow mineralisation, while Amara Minerals cracked a 102-metre intercept to reinforce the structural architecture of its premier Victorian gold-antimony system. So let’s dive in.

HARANGA RESOURCES LTD (ASX: HAR)

Project: Lincoln gold project, California, USA
Hit: 32m at 10.41g/t gold from 143m downhole

High-grade underground mining exploration thrives on structural continuity, and this week Haranga Resources claimed the top step on the podium after turning a meticulous dewatering campaign to gain access into a spectacular high-grade gold revelation.

Undertaking the first diamond core holes of its highly anticipated Phase 2 underground drilling program at the company’s historic Lincoln gold project, the company delivered a monumental bedrock intercept from the very first rod put down the hole.

The standout diamond hole, drilled from the recently restored XC11 development level into a little-tested zone along the southern edge of the existing resource, sliced through a tightly folded, structurally controlled gold system to deliver a spectacular 32m at 10.41 grams per tonne (g/t) gold from 143m downhole.

Highlighting the remarkable grade distribution and absolute tenor within the core of this system, the single continuous interval generated an extraordinary 13 separate one-metre sample assays that exceeded 10g/t.

The high-grade distribution peaked with a blistering one-metre individual assay roaring up to 51.4g/t gold from 152 metres downhole, validating the genuine bonanza nature of the mineralisation.

What makes this performance globally significant is that the breakthrough hit successfully bridged the spatial void between two previously separate, thinner modelled lodes. By conceptually merging these mineralised zones into a singular, cohesive domain of immense grade density, the result is expected to immediately upgrade geological confidence ahead of mine planning.

The commercial and strategic appeal of the project is heavily underscored by its location within California’s legendary Mother Lode Gold Belt, a prolific geological province renowned for hosting multi-million-ounce gold deposits that have historically produced at average grades exceeding 10g/t gold.

Furthermore, the project benefits from an enviable operational status; the ground features established underground access points, a fully permitted conditional use status to mine up to 1000 short tons per day and a mill circuit that was actively producing gold as recently as 2022.

With the first phase of dewatering and decline restoration now complete along the Stringbean Alley corridor, drill rigs are turning their bits continuously to complete the remaining 16-hole underground campaign.

This upcoming pipeline of robust data will feed directly into the company’s preliminary feasibility study, which is expected to accelerate Haranga along a trajectory towards converting 402,000-ounce maiden JORC-compliant gold resource into a sustainable, high-value ore reserve operation.

Terra Metals’ reverse circulation drill rig operating at the company’s Southwest prospect in its Dante Project in WA’s West Musgrave region. Credit: File

TERRA METALS LTD (ASX: TM1)

Project: Dante Project, Southwest prospect, Western Australia
Hit: 194m at 1.01g/t 3E (combined platinum, palladium and gold) and 0.17 per cent nickel from 15m downhole

Bulk-tonnage tier-one scale is the ultimate prize for base and precious metal explorers, and runner-up Terra Metals has delivered just that by unlocking a colossal near-surface magmatic broadside at its Dante project in Western Australia.

Reverse circulation (RC) drilling targeting immediate extensions of shallow mineralisation has intersected spectacular, continuous thicknesses of platinum group elements, copper, and nickel from shallow near-surface depths.

The headline performance came from an RC drillhole that pierced a stacked sequence of primitive mafic-ultramafic rocks and returned an aggregate 194 metres at 1.01 grams per tonne (g/t) 3E, combined platinum, palladium and gold, coupled with 0.17 per cent nickel from a depth of just 15 metres.

Demonstrating the rich accumulation of sulphides within this massive package, the hole revealed high-grade internal reef zones, including a sharp 24m at 1.84g/t 3E, 0.19 per cent copper and 0.27 per cent nickel from 43m depth, alongside an uncommonly high-grade deep segment of 9m at 3.53g/t 3E from 185m downhole.

Geologically, these shallow results are profoundly significant because they demonstrate an impressive platinum-enrichment profile, yielding a near-balanced 1:1 platinum-to-palladium ratio compared to the palladium-dominant mineralisation historically intercepted at depth.

This metal distribution confirms excellent near-surface consistency across the Southwest Prospect, pointing to a possible highly lucrative, low-strip, open-cut mining and selective processing style of operation which could vastly catalyse the project’s economics during its early production phases.

The asset sits squarely within the West Musgrave region, one of the world's premier layered mafic-ultramafic complexes, which is globally recognised for hosting mega-scale feeder-style discoveries like the multi-commodity Nebo-Babel nickel-copper-gold PGM sulphide deposit in the western part of the Musgrave block.

The company's drill rigs are currently processing more than 40,000 metres of additional drilling samples to feed into a comprehensive structural model. This substantial data pipeline will drive Terra Metals toward a planned maiden mineral resource estimate in the first quarter of 2027, paving a solid technical path toward a definitive scoping study.

AMARA MINERALS LTD (ASX: AM3)

Project: Apollo gold and antimony project, Central Victoria
Hit: 102.3m at 2.29g/t gold from 140.5m downhole

Victoria's Melbourne Zone continues to solidify its reputation as a premier exploration hotspot, and Amara Minerals has confidently taken up third place on the Big Hits podium after delivering a spectacular, century-scale gold intersection from its flagship Apollo Project.

Boring clean through the centre of the high-grade Dig Fault Zone, the company's maiden diamond drilling campaign has successfully validated historic models while unlocking exceptional depth potential.

The standout diamond drill hole intercepted strongly faulted, broken metasediments to return a magnificent downhole width of 102.3m going 2.29g/t gold from a depth of 140.5 metres, translating to an estimated 27.30-metre true width.

Highlighting a potent, premium core operating inside this broad geological system, the interval included a higher-grade internal zone of 66.8m assaying 3.08g/t gold, which was further anchored by an absolute bonanza core of 11m at 12.79g/t gold from 177.1m downhole.

The commercial profile of the Apollo system is enhanced by its metal diversity, hosting substantial antimony-bearing stibnite that shares close geological and intrusive structural characteristics with Alkane Resources’ high-grade Costerfield mine and Southern Cross Gold’s nearby Sunday Creek deposit.

Historically, gold across this structural corridor is associated with quartz-muscovite vein networks and stockwork stringers, occurring as highly favourable free grains and fine disseminations.

Amara is currently executing a 2000-metre diamond coring program, with multiple holes still waiting on assays already logging preliminary visual observations of fine gold at comparable depths to the south. This robust exploration runway continues to confirm that the system remains entirely open at depth and along strike.

With assay workflows picking up the pace at local laboratories, these broad high-grade gold intersections look likely to provide the definitive geological foundation required to confidently support the evaluation of a potential maiden mineral resource estimate.

Is your ASX-listed company doing something interesting? Contact: matt.birney@businessnews.com.au