The project is located in the Buller coalfield, New Zealand. The Denniston Plateau is a north west dipping plateau bounded to the west by the Papahaua Overfold/Kongahu Fault zone, and to the east by the Mt William Fault. The defined resource is contained within the Eocene aged Brunner Coal Measures. The coal measures consist of a fluviatile sequence of fine to very coarse sandstones, siltstone, mudstone and coal seams. The deposit generally has a single extensive seam with some localised splitting of the seam. The coal thickness can be up to 12m but generally averages 4-5m vertical thickness. The dip of the plateau reflects the dip of the coal bearing sediments with localised exposures of basement units at structural highs and within incised gullies. Little to no Quaternary deposits or soils overlay the Brunner Coal Measures with overburden generally around 40-50m. A strong trend in coal rank exists across the deposit with coal rank increasing from east to west. The main coal seam varies in thickness from less than 1m thick up to 14m thickness locally. Depth of cover varies from 0m at outcrop to over 150m at the eastern margin of the Mt William Fault. Inferred and Indicated resources include coal up to 130m below surface, while the measured resource includes coal up to 75m below surface. The deposit roughly covers a 6.5km by 4.5km area. The model is bounded by the Escarpment Fault to the south, the Waimangaroa Gorge to the north, and the Mt William Fault to the east.

Production from Escarpment began in 2014 and the mine was placed in care and maintenance in May 2016.

The development of the Escarpment, Whareatea West and Sullivan Coal Resources assumes mining methods consistent with similar or other BRL open pit mining operations. The preferred mining method is conventional truck and shovel open pit mining at an appropriate bench height.

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