South Alligator River, West Arnhem Region, Northern Territory, Australiai

Regional Level Types
South Alligator River	River
West Arnhem Region	Region
Northern Territory	Territory
Australia	Country

Exploration for uranium began in the area in the 1950s at the request of the USA and UK governments. This resulted in thirteen small uranium mines opening around the headwaters of the South Alligator River, which were operational from 1953 to 1964, producing pitchblende concentrates.

Most of the deposits were found in the Koolpin Formation, of carbonaceous, chloritic and in part pyritic (black) shale and slates, except for Coronation Hill where uranium was found in a volcanic neck. The mineralisation is found close to or in contact with the Carpentarian Sandstone with dolomites as reef breccia occurring close to the deposits.

The Koolpin Formation is overlain with a strong angular unconformity of Carpentarian rhyolite flows and pyroclastics of the Edith River Volcanics, and by sandstone, congolomerate with minor interbedded volcanics of the Kombolgie Formation. This is intruded by volcanic necks of the Edith River Volcanics, and by sills and dykes of dolerite, gabbro, and diorite of the Zamu Complex, as well as the Malone Creek Granite. The deposits are uranium, with subordinate gold, and minor copper, lead and phosphate rocks.

The northernmost is the Rockhole group of mines, then 50 kilometres south-east El Sherana, Koolpin, Scinto, Skull, Saddleback Ridge and Palette mines. A further 50 kilometres south-east is Coronation Hill. The Sleisbeck mine is 40 kilometres south-east of Coronation Hill in the Katherine River valley, however all references found include it in the South Alligator mineral field. Likewise, Moline is 50 kilometres west of the South Alligator River uranium mines and was used to process ore from some of the mines.

Minor deposits with no commercial production and not listed on Mindat include Airstrip, Monolith, Scinto 1, Cliff Face and the Coirwong uranium prospects. There is also a sub-economic small copper prospect 6 kilometres north-east of the Coirwong Gorge.

United Uranium NL mined the central and southern deposits. A gravity separation plant was constructed in 1956, 2 kilometres west of the El Sherana camp.

The Rockhole group of mines was originally operated by South Alligator Uranium NL. In 1958, they constructed a small mill at the Rockhole mine, for this and nearby deposits. It closed in 1961, and the ore was instead transported to Moline to be processed. United Uranium eventually purchased all the leases on the field, and held these until the last mine closed in 1964.

The mines at this time were simply abandoned. Tailings, shafts, open pits, the Rockhole and El Sherana mills and camps all remained untouched. Some tailings over the years washed into nearby creeks.

Subsequently, the Kakadu National Park was extended to incorporate the area of the mines. This, together with public concern over abandoned radioactive material, led the Australian Government to undertake what it called 'remediation work' at all the mine sites in 1991 and 2001.

This involved demolishing and burying on-site the mills and camps. Filling in the open pits. Placing grates on shaft openings (while still allowing access for bats, who apparently have no concerns about radioactivity). All the tailings were removed to Moline and encased in earth.

Clearly the erosion of any sort of tailings into streams needs to be addressed, maybe with better containment on-site. The writer questions the need for the large amounts of money spent. Scientific reports about radioactivity at the locations, stated someone would have to camp at the sites for several weeks to reach the minimum level of a radioactive threat to health.

The remediation work destroyed part of Australia's mining heritage, prevents study of the deposits, and also any specimen collecting by people with experience and knowledge on how to safely store these specimens. Informative warning signs could have been erected, and the danger accessed by visitors, who would take responsibility for their own safety.

The exploration for uranium in the area started in 1944 at the request of the UK and USA governments. Sixteen deposits were discovered in the South Alligator River valley, and thirteen developed into mines between 1954-1964, in what was described as a uranium rush to the area.

The northernmost group contains Teagues, Rockhole Creek and Sterrets mines. Fifty kilometres south-east is the El Sherana, Koolpin, Scinto, Scinto 6, Palette, Skull, and Saddle Ridge mines. A further fifty kilometres south-east of here is Coronation Hill, and 40 kilometres south-east of this in the upper reaches of the Katherine River, the Sleisbeck mine.

Ore from Sleisbeck was transported to Rum Jungle, 85 kilometres south of Darwin for processing. A processing plant was constructed at the Rockhole Creek mine for nearby deposits.

The largest producers were El Sherana, Saddle Ridge and Coronation Hill.
11 0000 ounces of gold was also recovered from the field as a by-product of the uranium processing.

The mines were abandoned in the mid 1960s with no rehabilitation. Since this time, the Australian Government has removed the tailings from the mines for storage elsewhere. The general impression is little remains.
The most northerly of the South Alligator valley uranium mines. Rockhole, Sterrets, O'Dwyers and South Alligator mines are nearby to the south-east. Ore was processed at a small treatment plant constructed in 1958 at Rockhole, then from 1961 at Moline, 50 kilometres east of Pine Creek. South Alligator Uranium NL discovered the deposit and operated the mine. In the early 1960s, United Uranium NL took over all the leases on the field until the last mine closed in 1964. Australian Government information states in recent years all the mines on the field have been rehabilitated, and the tailings carted off for storage off-site.

Uranium mine. Discovered and mined by South Alligator Uranium NL. Mining started in the late 1950s, and a small treatment plant was built in 1958 for the Rockhole mine, and nearby mines. Teagues is just to the north-west, Sterrets and O'Dwyers just to the south-east and the South Alligator mine a short distance to the south-west. In 1961, the treatment plant closed, and ore from all these mines was carted off to Moline, 50 kilometres east of Pine Creek. In the early 1960s, all the leases on the field were taken over by United Uranium NL, until the last mine closed in 1964. According to Australian Government information, all the mines on the field have been rehabilitated in recent years, and tailings carted off-site for storage.
One of several former uranium mines at the northern end of the field, with Teagues, Sterrets, South Alligator and Rockhole Mines. Ore was processed initially at a small treatment plant constructed in 1958, and then from 1961 at Moline, 50 kilometres east of Pine Creek. The deposit was discovered by South Alligator Uranium NL and subsequently mined by them. In the early 1960s, United Uranium NL took over all the leases on the field until the last mine closed in 1964. According to Australian Government information, all the sites have been rehabilitated and tailings removed for storage elsewhere.
One of many former uranium mines at the northern end of the field, including Teagues, Sterret, O'Dwyers, and Rockhole mines. Ore was processed at a small treatment plant constructed in 1958 at the Rockhole mine, then from 1961 at Moline, 50 kilometres east of Pine Creek. The deposit was discovered and mined by South Alligator Uranium NL, until the early 1960s when United Uranium NL took over all the leases on the field until the last mine closed in 1964. According to Australian Government information, in recent years the sites have been rehabilitated, and the tailings removed for storage elsewhere.

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