Basin fill consists of sedimentary rocks of the Karoo Supergroup, with maximum thickness of 1,500 metres (4,900 ft).

[5] There are few bedrock exposures in the Ellisras Basin; in most of the area, the relatively flat-lying sedimentary rock is covered by sands and soils.

[7][6] Some sources also identify the overlying Wellington Formation, predominantly a mudstone,[8] as a Dwyka Group equivalent.

[1] The Waterberg Coalfield deposits are contained in the Grootegeluk Formation,[12] and may account for over 50% of South Africa's coal reserves.

Mining and utilisation of the coal is expected to be constrained by its depth, high ash content, and structural complexity.

[17] There is interest in the potential for coalbed methane development from deep coal beds in the Ellisras Basin, particularly in the northeastern parts of the basin where the Grootgeluk Formation coal is found at depths greater than 300 metres (980 ft).

The high vitrinite content of the coal indicates a significant potential for coalbed methane production.

[18][19] As of 2011, the Anglo Operations mining group had begun investigating the basin's methane potential by drilling more than 70 wells and conducting production tests.