Regionally the Ashford coal measures are expressed as a narrow (< 10km wide) 80 km long basin, stretching from the Queensland border in the north to Inverell in the south, overlying uncomformably a Carboniferous age basement.

Put simply the geology of the tenement consists of a deformed metamorphosed Carboniferous basement unconformably overlain by the Ashford Coal Measures. To the west a leucogranite intrusive of the New England Batholith intrudes the Carboniferous sequence. The intrusive has had a low angle thrust fault shear the top of the pluton and displace it over the Permian coal measures. Weathered Tertiary age material intermittently covers the landscape with Quaternary alluvials from the Severn River interrupting the very top exposures.

The Ashford Coal measures are comprised of freshwater lithic conglomerates to sandstones generally white in colour and grey carbonaceous shales. Below the Ashford seam the conglomerates are comprised of rounded pebbles set in a grey shale matrix. Limited studies indicate the source of the Permian sediments appears to be the underlying Carboniferous age formation.

The Ashford Seam is the principal coal seam and occurs between 10 to 30m above the Carboniferous/Permian unconformity. The Bonshaw Seam, a minor and low quality seam lies a further 50 metres above the Ashford seam and is generally 2 metres thick with interbedded shaley coal banding.

The roof of the Ashford seam is a competent lithic conglomerate with a shaley and clayey matrix.

The Ashford seam strikes approximately 10 degrees magnetic and dips 25 to 30 degrees to the west of the Carboniferous/Permian interface in the east and has been found to flatten out to 15 to 16 degrees under the Severn fault and granite to the west.

The seam thickness varies from over 20 metres true thickness to less than 3 metres. Generally the seam has an average thickness of 9 metres and better for approximately 3km of strike.