Trinex mining in Western Australian outback

Mount Hardy Zinc-Copper Project

The Mount Hardy Project is located on the Tanami Highway, 300km north-west of Alice Springs and 20km west of the town of Yuendumu. The Project comprises several high-grade structurally-controlled precious and base metal oxide and sulphide targets generated from geochemistry and geophysics, including the Hendrix Deposit for which a Maiden Mineral Resource estimate was completed in 2019.

Previous Exploration

The Mount Hardy Copper field was discovered by W.W. Braitling in 1935 with sporadic small scale mining occurring through to the 1970’s. The BMR drilled seven diamond holes into the main Mount Hardy Prospect, a historic “mine” area in 1967-68. Core from this drilling is available at the Alice Springs Core library. Tanami Gold completed minor surface exploration in the area targeting structural gold in 2002-03 but no other systematic exploration has been carried out in the area.

A 900 line kilometre HELITEM survey was completed by TNG Ltd on 2012 with numerous targets identified for follow-up. Exploration drilling carried out between 2013 and 2017 returned copper grades of >1% Cu from five prospect areas (Browns, Mt Hardy, EM1 – Hendrix, EM2 – Lennox and EM4).


Significant drill programs continued across the project in 2018 and 2019 culminating in the release of the Maiden Mineral Estimate at Hendrix in July 2019. The Resource comprises 2.6Mt @ 6.7% Zn, 0.9% Cu, 1.5% Pb and 35 g/t Ag which is made up of 175,000 tonnes Zn, 22,500 tonnes Cu, 40,000 tonnes Pb and 2.9 million ounces of Ag (at a 1.5% Zn cut-off).

Significant drilling intersections at Hendrix which contributed to the resource estimate include:

  • MHDD0021A : 13.45m @ 15.9% Zn, 0.9% Cu, 5.75% Pb, 83 g/t Ag from 358.55m;
  • MHDD0040: 55.75m @ 1.0% Cu, 1.5% Pb, 3.3% Zn and 43.5 g/t Ag from 131.5m, including:
    • 7.92m @ 1.4% Cu, 5.0% Pb, 13.8% Zn and 212.3 g/t Ag from 179.38m;
  • MHDD0043: 35.54m @ 14.7% Zn, 2.92% Pb, 0.91% Cu and 59 g/t Ag from 431.54m, including:
    • 11.29m @ 22.9% Zn, 3.35% Pb, 1.0% Cu and 58 g/t Ag from 443.61m;
  • MHDD0042: 24.54m @0.68% Cu, 0.29% Pb and 4.86% Zn from 619m, including:
    • 12.68m @ 1.19% Cu, 0.47% Pb and 8.21% Zn from 629.62m.

Expansion of Exploration

Additional significant intersections were obtained from drilling at the Browns and Lennox Prospects indicating the potential to expand the current resource.

Exploration in mid-late 2019 focused on the greater Mt Hardy Project in order to identify additional areas of base metal mineralisation. Detailed mapping and systematic surface sampling around known prospects combined with reconnaissance mapping and sampling over areas of outcrop identified seven new areas of mineralisation worthy of further exploration. Reconnaissance RC drilling was completed in late 2019 over six target areas, Gilly, Gilly North, Laver, Hendrix NW, Hendrix South and Linda Jane.

Encouraging results were received from the Hendrix extensions along with the Gilly, Gilly North and Laver prospects.

New areas of base metal anomalism were also identified from sampling of historic RAB drilling (previously only assayed for Au). Best results were in the northwest extending away from the historic Linda Jane outcropping gossan.

Exploration at Mt Hardy was limited significantly between 2020 and 2022 due to travel and quarantine restrictions imposed during the COVID-19 pandemic.

Sampling completed during 2022 concentrated on a detailed approach to areas of exposure or residual soil profiles where surface sampling is deemed effective, including a large relatively unexplored area NE of Hendrix in the vicinity of the newly defined Gilly and Laver Prospects. pXRF sampling was completed on a 100x20m grid and defined numerous Zn-Cu-Pb soil anomalies leading to the discovery of outcrops of Zn-Cu-Pb oxide mineralisation and gossans.

The sampling was extended and now covers most of the 8x3km trend from Browns in the west through to Mt Hardy in the east, resulting in new prospect areas, the Stardust-AB-Jack trend, Lehmann trend and Pacquiao anomalous zones.

Drilling has recently been completed over several of these anomalous zones.