Arrow Minerals Advances Yarraloola Copper Project with Historical Core Insights and 2026 Drilling Plans

Discovery of Historical Drill Core Revitalises Yarraloola Exploration

Arrow Minerals Limited (ASX:AMD) has struck a rich vein of historical data at its Yarraloola Copper Project with the discovery of seven diamond drill holes from the 1970s preserved at the Geological Survey of Western Australia (GSWA) Core Library. This rare find offers a tangible connection to past exploration efforts, with the cores confirming mineralised intercepts including a standout 32.7 metres grading 0.7% copper, 0.3% lead, 16.3 g/t silver, and 0.4% zinc from one hole (YD2) starting at 54 metres depth. Notably, gold assays were not conducted historically, but recent surface rock chip sampling adjacent to these drill sites has revealed gold grades up to 0.95 g/t, hinting at untapped potential beyond the base metals.

Validating a Volcanogenic Massive Sulphide Model

Inspection of the cores supports the long-held hypothesis by Western Mining Corporation (WMC) that Yarraloola represents a volcanogenic massive sulphide (VMS) system. The cores display characteristic alteration minerals such as chloritic schist crosscut by quartz-carbonate-sulphide veins, with mineralisation comprising disseminated and vein-hosted pyrite, chalcopyrite, and galena. Arrow’s Managing Director David Flanagan emphasised the value of this discovery, noting that the preserved core and the GSWA's non-destructive HyLogger-4 spectral scanning, which maps mineral signatures invisible to the naked eye, are instrumental in refining the geological model and guiding the upcoming drill program. The HyLogger data, now publicly accessible, is being analysed to identify subtle alteration patterns that could vector toward new mineralised zones.

Targeting Multiple Prospects with Modern Techniques

Building on the historical groundwork, Arrow has identified three priority targets, Ava, Fraser, and the Yarraloola Copper Mine area, backed by recent infill gravity data and geophysical modelling by consultants Newexco. The company plans to deploy modern reverse circulation (RC) drilling to test these targets, with drilling preparations well advanced and coordinated with contractors. Additional geophysical surveys, including magnetics, gravity, and potentially induced polarisation, will extend along strike to refine targeting. Arrow also plans to integrate geochemical sampling and regolith mapping to complement geophysical data, particularly in areas with transported cover where soil sampling efficacy is uncertain.

Historical Data Limitations and Future Work

While the historical drilling and sampling provide a valuable foundation, Arrow acknowledges limitations inherent in vintage data. The drill collars were surveyed using local grids with some positional uncertainty, and many mineralised intervals were previously resampled, leaving limited core for new assays. True thicknesses of mineralisation remain undefined, and metallurgical recoveries are assumed based on analogues from other VMS deposits pending testwork. Arrow intends to resurvey drill collars with modern GPS to improve spatial accuracy and undertake further non-destructive core analyses including scanning electron microscopy and electron-probe micro-analysis to quantify mineralogy and trace element distribution, particularly gold in pyrite.

Strategic Positioning in a Prospective Region

Yarraloola sits within the Ashburton Basin, a geological province with a track record of significant gold and base metal discoveries such as Sulphur Springs, Paulsens, and Hemi. Arrow’s acquisition of an 80% interest in the project was completed in June 2026 following shareholder approval and was supported by a prior $2.25 million capital raising. The company’s methodical approach, leveraging historical data, advanced spectral scanning, and targeted drilling, positions it to unlock value in a region that has seen little systematic exploration for half a century.