The Ranger No. 1 and No. 3 orebodies contain about 124,000 tonnes l^Og in highly chloritized metasediments of the lower Proterozoic Cahill Formation within about 500 m of the projected sub-Kombolgie Formation unconformity. In both orebodies, oxidized and reduced uranium minerals occur chiefly in quartzose schists that have highly variable amounts of muscovite, sericite, and chlorite.

Below the oxidized zone, uranium occurs chiefly as uraninite and pitchblende disseminated through thick sections of quartz-chlorite-muscovite schist and has no apparent association with graphite or sulfides. In fact, graphite is rare and sulfides are generally low in abundance (<0.5 percent). Higher ore grades occur in disrupted zones a few centimeters thick and in some quartz chlorite vein-like zones of uncertain origin. Uranium correlates strongly with chlorite, but not all of the many ages of chlorite have associated uranium. At least five textural varieties of chlorite are present and represent at least 3 ages. Preliminary microprobe analyses suggest that Mg-Fe-Al contents are relatively uniform. Apatite commonly occurs with chlorite. Uranium is not common in carbonate rocks and seems to occur only in disrupted zones that have chlorite alteration.

The structure of the orebodies is outwardly simple, particularly in No. 3; dips are less than 40° on most lithologic contacts. The No. 1 orebody is in a basin-like structure about 400 m wide that probably formed in part by pr ........

Mining at Ranger involved a conventional open cut process, which begins with drilling and blasting. Pit 1 was mined out in 1994 and mining in Pit 3 ceased in November 2012. Prior to the completion of mining in the pits, mined material was categorised by a discriminator, which measured the gamma emissions of each load to calculate uranium grade for either stockpiling or immediate processing according to the grade of the ore (percent uranium oxide). Low-grade ore will be returned as backfill to the mined-out pits and covered by unmineralised rock to create the final landform.

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