Along the structurally disturbed north-eastern edge of the Bowen Basin, the coals range in rank from anthracite to low volatile bituminous, and deposits tend to exhibit a complex structure. Coals in the central part of the basin are medium to high volatile bituminous and include the best coking coals. Structural deformation in these deposits is generally relatively mild.

Coal-bearing horizons have been preserved at many stratigraphic levels throughout the Bowen Basin, but deposits of economic importance are restricted to four groups.

Group II coal measures, also of Early Permian age, occur as several unconnected deposits located around the northern and western margins of the basin. These include the Collinsville Coal Measures in the north.

Group III coals of Late Permian age were deposited on the Collinsville Shelf, under conditions which varied from a marine- influenced deltaic environment in the German Creek Formation, to dominantly fluvial flood plain environments in the Moranbah Coal Measures. These formations contain most of the high-grade coking coal deposits mined in Queensland.

Collinsville Coal Measures of Early Permian age, containing up to nine coal seams; extensive faulting and igneous intrusions have affected all seams to varying extents, with five seams currently worked; average thicknesses of these are: Garrick — 2.6m; Scott — 1.8m; Denison — 2.8m; Bowen — 6.5m; and Blake — 10m.

The Collinsville operations comprise the Collinsville open-cut mine, and the small Pipeline mine about 15km to the south-east. The mining method for both mines is truck and shovel for overburden removal, as well as a dragline at Collinsville open-cut.

Preparation plant - Dense medium and classifying cyclones.

In late 2020, Collinsville transitioned back into producing coking coal, while still producing a secondary thermal product. In January 2021, Collinsville’s first coking coal sale since 2013 was successfully produced and loaded.