The Charley Creek project area is dominated by the MacDonnell Ranges which trend east-west to the immediate south of the project tenements. The MacDonnell Ranges are an uplifted, tilted and dissected plateau of basement Proterozoic rocks comprising metasediments, mafic and felsic granulites, gneisses, migmatites and granites. To the south, Devonian sediments form the northern rim of the Amadeus Basin. The northern boundary of the MacDonnell Ranges is marked by a major fault zone, the Redbank Thrust Zone. North of the Redbank Thrust Zone the basement rocks of the Arunta Block are largely buried beneath flat-lying plains, with occasional hills of basement rocks protruding through the younger sediments. The buried basement rocks commonly show a zone of saprolitic weathering, overlain by Tertiary sediments and calcrete, overlain in turn by Quaternary colluvial and alluvial gravels and sands, representing outwash fans from the weathering of the older basement rocks. The basement rocks contain elevated values of uranium and thorium and are also the source of the rare earth minerals found in the Charley Creek alluvials. Drilling elsewhere has intersected up to 80m of Quaternary alluvial sands, gravels, meta-sediments and calcrete, the depth of mineralisation material varies across both Western Dam and Cattle Creek.
The rare earths in the alluvials are contained in the rare earth phosphate minerals, monazite ([Ce, La, Y, Th]PO4) and xenotime (YPO4).
Heavy minerals separate by density differences, visible as a black band of heavy minerals pictured on the test shaking table above.