The deposit type is rare in this part of Queensland. It is a flat lying residual oxide deposit of a weathered gabbro intrusion that has had modifications from surface water flow and soil creep. The host rock comprises a combination of weathered material and alluvium. Ilmenite mineralisation occurs as liberated fine grains often concentrated by surface water into more slimes-rich material but the concentration may in part be related to an underlying primary concentration in the gabbro. The gabbro appears to have a primary mineralogical zonation associated with the arcuate margin of the intrusion. The ilmenite has been widely distributed throughout the mining lease with no obvious specific lateral concentrations.

The mineralisation is associated with the Goondicum Gabbro which Groen (1993) had mapped from the crater rim to the centre as comprising a ‘poikilitic marginal zone’ (hornblende gabbro), ‘lower zone laminated gabbro’, and ‘macrorhythmic zone’.

The relatively complex weathering history of the gabbro has produced two main host types for ilmenite mineralisation. The 'clay/sand' unit or ‘CS’ is believed to be an eluvial/colluvial deposit i.e. some in-situ material and some transported material possibly due to both gravity slip and alluvial processes. The second type is 'decomposed gabbro' or ‘DG’, implying a less weathered eluvial or in-situ deposit. A subset of the clay/sand unit is the 'colluvium' unit or ‘CL’, and this may have had a more water transported-related origin. The CS occurs at or near surface and includes the uppermost 20-30cm of the soil profile, designated in the drillhole logging as 'soil horizon' or ‘SL’. The CS can range in thickness, up to several metres, especially where the CL unit is associated. The CL is an important sub-set of the clay/sand mineralisation, having high slimes content, and may have formed from localised damming of alluvial channels resulting in localised flooding where the clay material in suspension settled out in depressions.

Ilmenite deposits also occur along modern stream channels as terrace remnants, which the reactivated stream has partly eroded. Less frequently, palaeo-stream channels are encountered which are filled with gravity flow colluvium with variable ilmenite grades.

The mineralisation is essentially flat lying with an undulating base. For the ML its dimensions are 3,000 x 1,500 metres with an approximate viable range in thickness of 2–10metres (low grade mineralised DG can add to a maximum thickness of 25metres). For the MLA the mineralisation dimensions are 4,000 x 2,000metres with an approximate viable range in thickness of 2–10metres (low grade mineralised DG can lead to a maximum thickness of 25metres).

The fundamental geological control to the mineralisation is the underlying spatial distribution of the gabbro and its ilmenite content, followed by the topography at the time of the different weathering/erosion phases. Ilmenite grades are not entirely related to specific weathered rock types although there is a marked segregation between the high slimes units, CL and CS_H, having higher grades than the low slimes CS_L and DG host units. The ilmenite grades of the DG unit are more directly related to the original grade within the gabbro.

The land is cleared of vegetation (trees and grass) using a bulldozer to prepare the area for mining. Approximately 20cm of topsoil is removed and stockpiled for later rehabilitation. A dry open pit mining method is proposed for ore mining using a combination of scrapers, and an excavator and truck model. The mineralisation is relatively easy digging for an excavator. Normal mining practice will be for the excavator to sit on top of the mineralisation being mined and load trucks in the pit below the excavator. This reduces the cycle time of the excavator to maximise excavation efficiency. Four 40 tonne 6WD trucks will be used to haul the mineralisation from the excavator to the ore stockpile at the feed preparation plant (FPP). The average haul distance for the ML will be 300metres and the maximum haul distance will be 2,000metres. The mining operation will also utilise scrapers on short haul, low vertical lift cycles to remove the mineralisation and deliver it to the FPP. The scrapers are more suitable for mining the thinner material which is outside the gullies. Two scrapers will be used mostly for mining in the shallow areas, while the excavator and trucks will concentrate in the gullies.

The feed to the plant comprises mineralised sand grains including ilmenite, magnetite, apatite and feldspar as both discreet and composite particles held within a barren clay matrix. Characterisation work done as part of project development showed that the valuable heavy minerals present in the feed can be recovered from the -1mm +53micron size fraction using conventional heavy mineral sands processing equipment. Once the minerals are liberated the separation processes at the wet concentrator plant are able to reject gangue minerals while recovering ilmenite and apatite product streams by exploiting the differences in their physical properties. The differing behaviour of the geological domains (CL, CSH, CSL, DG) through the process flowsheet means that the ROM material needs to be stockpiled ahead of the plant and blended before being loaded into a feed receival unit with a frontend loader. The first processing stage comprises screening, deagglomeration and water recovery in the feed ........