The rocks of the Cape York Peninsula are divided into two geological units: the sedimentary rocks on the western side of the peninsula and the igneous and metamorphic rocks exposed in the hills on the eastern side of the peninsula (the Coen Inlier).

The Cape York Peninsula bauxites are confined to a dissected laterite plateau, known officially as the Weipa Plateau on the west coast of Cape York Peninsula. The Weipa Plateau is one of three geomorphologic land units that are of particular interest to the geology of the bauxite and kaolin resources. The other two units are the Merluna Plain and the Mapoon Plain.
• The Weipa Plateau is a low plateau, usually no more than a few tens of metres above sea level and has been dissected by various river systems resulting in a series of irregularly shaped islands. It is intensely weathered to a depth of 20 m to 30 m with the upper part of the weathered material reconstituted into various nodules as well as some partially cemented rocks. The flatness of the plateau has meant it has been immune to erosion other than by rivers eating away at the sides. Much of the plateau’s volume was removed in solution in the groundwater, which is also responsible for the formation of the bauxite. The sedimentary rocks of the Weipa Plateau fall into two categories:
- The Rolling Downs Group Sediments; and
- The Bulimba Formation Sediments (Weipa Beds).

• These two groups of sediments are eroded and weathered to form th ........

Weipa operations includes three bauxite mines East Weipa, Andoom and Amrun.

Bauxite ore in Weipa is found in a layer three to four metres deep in the form of small, red pebbles, called pisolites.

Vegetation is removed from the site to be mined and scrapers strip the topsoil (which varies in depth from one to ten metres). Front-end loaders use a shallow, opencut technique to load the bauxite, which lies below the topsoil, into bottom-dump trucks that carry the ore to the dump station. The bauxite is then transported to the beneficiation plant by rail or conveyor.

• As the Weipa orebodies are shallow, geotechnical risks are extremely low. Pre-production drilling is completed in order to provide better definition of the roof and floor contacts for the five-year mine planning process.
• Estimates include internal dilutional but no allowance for external dilution or mining recovery. Dilution and mining recovery are applied during the reserving process, not during estimation.
• A minimum mining thickness for the bauxite horizon of 0.5 m is used for the final determination of resource figures.

• Weipa bauxite is beneficiated through established techniques to improve product quality and handleability.
• This is achieved through the removal of the finer fraction and leaves the coarser material as product.
• The beneficiation process typically involves wet screening and may include the use of cyclones and classifiers depending on the part of the deposit being beneficiated.
• Expected bauxite recovery and quality from the beneficiation process is assessed through laboratory scale test work of samples generated from the resource drilling process.
• Bauxite mineralogy has been investigated through numerous studies, primarily using wet chemical techniques, to understand how it will react in the Bayer Process, which is used to extract the alumina at the refineries.
• A proprietary mineralogical calculator “MinCalc” is used to estimate bauxite mineralogy and Bayer processing grade for Cape York ore from the routinely collected elemental chemistry and thermog ........