Highlights

  • Yari Resources compiled 199 historical boreholes and wells at its Arcadia Coal Project in Queensland’s Bowen Basin.
  • The dataset comprises 43 historical coal exploration boreholes and 156 coal seam gas, petroleum and stratigraphic wells.
  • Arcadia’s existing 282.0Mt Coal Resource remains unchanged at 164.0Mt Indicated and 118.0Mt Inferred.
  • Preliminary observations east of the current resource footprint require validation before any resource revision can be considered.

Yari Resources Limited (ASX:YAR) is developing a coal project portfolio in Queensland’s Bowen Basin, centred on the Arcadia and Rolleston South projects. In its 3 November 2026 announcement, the company reported progress compiling and reviewing historical drilling information at Arcadia. The work broadens the geological dataset available for interpretation, but it does not constitute new drilling or an increase in the project’s reported Coal Resource. Yari is assessing whether these records support future modelling.

What Does the 199-Hole Database Contain?

The Arcadia database assembled by Yari Resources (ASX:YAR) contains 43 historical coal exploration boreholes and 156 coal seam gas (CSG), petroleum and stratigraphic wells. Of the latter group, 146 are within EPC 1054 and EPC 1772 and ten are outside those project tenements. The company is examining records from within and around its tenure to improve seam correlation and understand geological conditions beyond the area used in the existing resource model.

Coal-quality data are available for 62 boreholes, including 34 historical coal exploration holes and 28 CSG wells. The model currently incorporates approximately 5,400 lines of lithological logging and 2,058 lines of raw and washed coal-quality data. These are compiled historical records rather than results of a new Yari drilling campaign. Importantly, adding a well to the database does not automatically make it suitable for Mineral Resource estimation.

Why Is the Eastern Area Under Review?

According to Yari Resources (ASX:YAR), interpreted seam depths are generally within plus or minus 0.30 metres of the 2017 geological model and available downhole geophysical logs. Historical CSG wells east of the existing resource area generally suggest greater seam development at depth, alongside increased seam splitting. These are preliminary geological observations, not a quantified resource extension.

The company is repicking and correlating coal seams in historical wells while conducting geostatistical analysis to assess appropriate borehole spacing for potential resource classifications. Figures accompanying the announcement show historical well locations relative to the existing resource footprint and petroleum leases. Some mapped wells lie outside Yari’s project tenure, which does not establish additional resources.

What Remains Before a Resource Update?

Arcadia’s existing Coal Resource is 282.0 million tonnes (Mt), comprising 164.0Mt Indicated and 118.0Mt Inferred, as previously reported on 7 August 2026. Yari Resources (ASX:YAR) explicitly stated that its latest review does not change those figures. No new Mineral Resource, reclassification or Exploration Target was announced, and the historical review may ultimately leave the estimate unchanged.

There are material data gaps to resolve. Lithology logs for 23 wells have yet to be loaded, while 99 wells have no available lithology logs and will require seam interpretation from geophysical records. Further work includes capturing drilling and survey information, refining seam correlations, expanding coal-quality records and completing geological modelling. Any revised estimate would also require assessment of reasonable prospects for eventual economic extraction and review by a Competent Person.

Key Insights

The November 2026 update from Yari Resources (ASX:YAR) marks progress in geological data compilation rather than a confirmed expansion of Arcadia’s resource base. The 199-record dataset may help identify where additional work is most useful, particularly east of the existing footprint. However, the resource estimate remains unchanged, and future outcomes depend on data quality, geological interpretation, coal-quality assessment and independent technical review.