The Caval Ridge Project area is situated on the relatively undisturbed western limb of the northern Bowen Basin, which is perched at the southern end of the Collinsville Shelf. Economic coal seams occur in the terrestrial Moranbah Coal Measures which consist of 300 m depth of laterally changing sandstones, siltstones, mudstones, tuffaceous-claystones and coal. These coal seams were deposited on the eastern margin of the Collinsville Shelf, which provided a predominantly fluvial flood plain environment and is one of the structural elements of the Clermont Stable Block.

The economic coal seams of the and Caval Ridge Project areas occur mainly in the terrestrial Moranbah Coal Measures. Surface Tertiary alluvial along with surface Basalt flows in addition to weathering of the Permian sediments make up the variation in stratigraphy in the area. The target seams for the Caval Ridge Project are all seams in the lease above 30 cm thickness with primary targets of the Q seam - P seam zone, the Harrow Creek Seams and the Dysart Seams. Seam splitting is prevalent along the length of the lease making modelling complex, with a general trend to split to the north and also down dip. Seam naming in the region is based on the seam position
round the P Tuff, a 1 to 2 m thick regional marker.

In descending stratigraphic order the seams are briefly described as follows:
- The S seam is the highest seam stratigraphically and is considered to be the basal seam of the Fort Cooper Coal Measures. It is 3 to 4m thick with high inherent ash and numerous claystone partings, and is modelled as S01. The R seam is 1 to 2 m thick and has a high inherent ash content and is modelled as R01. These two seams are rarely found in the lease and only at the eastern margins.
- The Q seam comprises several coal intervals modelled as Q01, Q02, Q03 with a cumulative thickness of 2 to 3.5m. Through much of the project area, the Q seam is un-split (Q01), splitting in the central part of the area into Q02 and Q03.
- The P seam is together as one seam in the south and splits to the north. One stringer splits low to attach near the H162. The 3 major P seam units are modelled as P02, P07 and P08 and are named due to the association with the P Tuff that is consistent through this part of the Bowen Basin. P07 and P08 splits are present in most of the Caval Ridge project, with unsplit P02 occurring near the Pseam limit of oxidation (LOX) in the southern and central part of the Caval Ridge Project.
- The Harrow Creek group of seams is up to 12m thick and where fully coalesced is modelled as the H13 in the Harrow Pit in the centre of the Peak Downs Mine. From there it splits both to the north and south into a major separation as the Harrow Creek Upper, H16 and Lower, H15.
- Through most of the Caval Ridge Project area the Harrow Creek Upper sequence splits into the H161 and H162. The H161 always has a poor quality band at its base. This band, H06, is actually the upper ply of the Harrow Creek Lower sequence, which splits off the top of the Harrow Creek Lower and sits just beneath the Harrow Creek Uppers. As the Harrow Creek Lower seams develop to the north, six separate units split from the primary Harrow Creek Lower, which is modelled as H15. H08 and H00 split apart the H15, and then the H08 splits into H06 and H01. H00 occurs consistently through Caval Ridge Project area, with an average thickness of around 1.2m. At the northern extent of the current mining area and through into the Caval Ridge Project area, the H01 splits to H03 and H02. These splits merge back into the H01 (approx. 2.5-3m thick) in the northern part of the Caval Ridge Project.
- The Dysart Upper seam attains a maximum thickness of 3.5m where fully coalesced and is modelled as D47 but splits into multiple units at both ends of the lease. In the Caval Ridge Project area D47 splits to D43, D40 and D45. D43 and D40 shale out to the north D45 is identified through most of the Caval Ridge Project area, however it is often less than 0.3 m thick. None of these seams provide economic thicknesses except where their proximity to D04 enables it.
- The primary Dysart can be a single seam that reaches 5 m in thickness, and is then modelled as D05. North of Heyford Pit, it is divided quickly into 2 major splits over most of the project area. The D05 splits into D02 and D04 with further splitting off the bottom of the D04 forming the minor D0 seam. The D02 is generally stable but banding develops in some areas. The DL seam is a consistent 60 cm band that correlates under the D02 through most of the area. Two additional coaly bands sitting below the DL have been identified and modelled. These have been named the DLL (approx. 20 cm thick) and DLLL (10-20 cm thick).
- Two seams identified below the D02 have been named the D00 and C01 seams and a focus on their correlation from recent exploration programs has helped determine their extent. The D00 sits around 20 m below the D02 through much of the Caval Ridge Project area. It averages 1 m thick, but does thicken to 2.0 m in places. At this time, initial quality results indicate a high ash coal and poor yielding seam. C01 occurs 50-55 m below the D02 and is about 1 m thick. It has only been identified in a handful of drillholes. No quality data is currently available for the C01.

Caval Ridge is open-cut, using dragline and truck and shovel fleets for overburden removal.

Impurities are removed through washing and treatment at a coal handling and preparation plant. Coal is then transported by train to port, loaded onto ships and exported to customers.