The coal resource at the Duralie Coal Mine (DCM) is located within the Permian aged Gloucester Basin in NSW. The DCM is located in the southern closure of the main synclinal structure of the Gloucester Basin and is associated with the coal bearing strata of the Dewrang Group. The Dewrang Group comprises three main stratigraphic units, namely: Mammy Johnsons Formation; Weismantels Formation; and Duralie Road Formation. The coal seams mined at the DCM include: • the Weismantel Seams; • the Clareval Seams; and • the Cheerup Seams. The underlying basement rocks are principally volcanics of Early Permian (i.e. Alum Mountain Volcanics) and Carboniferous age that were folded during formation of the Gloucester Basin. The Early Permian and Carboniferous volcanic rocks are typically erosion resistant and form the more prominent ridges to the east and west of the DCM.

The Duralie Coal Mine (DCM) is an open cut truck and shovel operation.

The operations extract ROM coal from the Weismantel and Clareval seams at the base of the Gloucester Coal Measures. The deposit forms a synclinal structure with the open cut area located at the southernmost crop line within the main axis of the Gloucester Basin. The operation is now situated on the west limb of the syncline with seams dipping at about 50 degrees east. Mining is undertaken within ML1427 and ML1646 and includes the extension of the Weismantel pit to the north west and the inclusion of the Clareval seam parallel and to the west of the Weismantel seam.

Dips within the deposit vary from a shallow 5 degrees to an almost vertical profile. Consequently, a method of horizontal 3m to 4m benches is used as the primary extraction method. An average of 5m of free dig material is generally experienced at Duralie after which all waste material generally requires blasting.

Mining at the DCM was postponed in October 2018. Since this time periodic rehabilitation and PAF rehandling works have been undertaken. Mining at the DCM recommenced in February 2021 with ROM coal being extracted from the Weismantel Pit.

Mining in the Clareval pit was completed during September 2017. Clearing in advance of mining up to the approved disturbance limit in both Weismantel and Clareval was completed in 2018. No further clearing is proposed for the Duralie Extension Project (DEP).