Territory Stories

Heavy Metal Monitoring Alligator Rivers Region Uranium Province 1979



Heavy Metal Monitoring Alligator Rivers Region Uranium Province 1979


White, L.


E-Publications; E-Books; PublicationNT; Report No. LC82/1




Made available via the Publications (Legal Deposit) Act 2004 (NT).






Report No. LC82/1

File type


Copyright owner

Check within Publication or with content Publisher.

Parent handle


Citation address


Page content

Winds in the region although extremely variable are seen from studies at Jabiru East to be north to north westerly in the wet changing to east to south easterly in the dry. 1.6 Geology The Alligator Rivers Uranium Province lies in the north east corner of the "Pine Creek Geosyncline" with major uranium deposites at Jabiluka, Ranger (1 & 3), Koongarra and Nabarlek. The regional geology is composed of a stratigraphic succession which includes archaean materials. Most of the area is now covered with unconsolidated to semi consolidated sands, gravels and clays of quaternary and tertiary origin periods with lateritesation common. Generally the tertiary deposits are underlain by Mesozoic sediments of fine to medium sandstone and siltstone encompassing the "Bathurst Island" formation. The Mesozoic sediments are underlain by Pre-cambrian geologies. Middle Proterozoic "Nourlangie" schistose and arenaceous sediments of the "Kombolgie" formation overlay lower Proterozoic metasediments (of the "Cahill" and "Koolpin" formations), and have suffered intrusions by dolerites and phonoli tes . The Cahill and Koopin metasediments in turn overlay lower proterozoic to archean granites making up the "Nanambi" formation. It is within the stratabound Cahill metasediments close to the granite complexes that the major uranium mineralization occurs (Masood, 1981). Throughout the Pine Creek geosyncline, uranium is found in sequences containing carbonaceous and carbonate rocks, and this association is thought to indicate that carbon or carbonate rocks may have played an important role in the formation of uranium deposites. (Needham & Stuart-Smith, 1980). Carbon under reducing conditions before or after lithification 'may have fixed uranium from surface or subsurface waters. Uranium may have been localised by absorption onto clays within carbonate rock fractures (Ferguson et a1., 1980) or during the metasomatising of brines by carbonate rich groundwaters (Crick & Muir, 1980). The ore forming processes have taken place over long periods with uranium datings of 1700-900 Ma being reported by Hills & Richards (1976).* Each of the major deposits in the Cahill formation occurs in zones of faulting and brecciation and there has been no significant movement away from this stratabound sequence. (Nedham & Stuart-Smith 1980). Many other metals have been reported in the Uranium Province. All the known gold occurs in association with the uranium mineralisation, with the only economically viable quantity being so far reported at Jabiluka 2. Other minor metals such as lead and zinc occur within the quartz breccia faults of the Nananabu complex west of Mt. Cahill. Tin is found within the Mt. Partridge range and iron in a quartz hematite rock over the Nourlangie schist north of Jim Jim Falls. LNL25 AI0

Aboriginal and Torres Strait Islander people are advised that this website may contain the names, voices and images of people who have died, as well as other culturally sensitive content. Please be aware that some collection items may use outdated phrases or words which reflect the attitude of the creator at the time, and are now considered offensive.

We use temporary cookies on this site to provide functionality.
By continuing to use this site without changing your settings, you consent to our use of cookies.