Mary Kathleen Mine

Old Mary Kathleen Uranium Mine

Useful Information

Location:	Mary Kathleen. Highway A2/83/Barkly Highway halfway between Mount Isa and Cloncurry. (-20.747000, 140.012300)
Open:	no restrictions. [2022]
Fee:	free. [2022]
Classification:	Uranium Mine Open Cast Mining
Light:	n/a
Dimension:	L=1 km, W=480 m, VR200 m.
Guided tours:	self guided.
Photography:	allowed
Accessibility:	no
Bibliography:	T.A.P. Kwak, P.B. Abeysinghe (1987): Rare earth and uranium minerals present as daughter crystals in fluid inclusions, Mary Kathleen U-REE skarn, Queensland, Australia. Mineralogical Magazine, Volume 51, Issue 363, December 1987, pp. 665-670. online DOI pdf G. M. Derrick (1977): Metasomatic history and origin of uranium mineralization at Mary Kathleen, N.W. Queensland. BMR d. Austral. Geol. Geophys. 2, 123-30. pdf pdf T.A.P. Kwak (1985): Zoning, mineralogy, fluid inclusions and genesis of the Mary Kathleen U-REE skarn, Qld., Australia Econ. Geol. (in press).
Address:	Northwest Tours, 19 Marian Street, Mount Isa, QLD, Tel: +61-7-4744-8577. E-mail:
As far as we know this information was accurate when it was published (see years in brackets), but may have changed since then. Please check rates and details directly with the companies in question if you need more recent info.

History

1860s	Mary Kathleen first settled.
1954	uranium first discovered by Clem Walton and Norm McConachy.
1955	Mary Kathleen Uranium Ltd formed by Rio Tinto Mining to develop a mine and service town.
1956	contract with the United Kingdom Atomic Energy Authority signed.
1956-58	architect-designed town built.
1958	Mine and Township officially opened by Robert Menzies, Prime Minister of Australia and Frank Nicklin, Premier of Queensland.
1963	major supply contract satisfied ahead of schedule, works closed down.
1974	mine reopened.
1981	deposit exhausted.
1984	became the site of Australia's first major rehabilitation project of a uranium mine, which was .
1985	rehabilitation project completed,
1986	rehabilitation project wins award from the Institution of Engineers Australia for environmental excellence.

Geology

The Mary Kathleen uranium deposit is contained in west-dipping middle Proterozoic calcareous, dolomitic and alkali-rich metasediments of the Corella Formation. An early, higher temperature metasomatic event has formed K feldspar-rich and scapolite-pyroxene bands. The intrusion of the Burstall Granite metamorphosed the rocks to hornblende hornfels grade. A swarm of rhyolite and microgranite dykes are also associated with this granite intrusion.

A lower temperature metasomatic event has resulted in extensive garnetizatlon and skarn replacement and uraninite-allanite mineralization. The fluids of this second event were enriched in Na, Cl, H₂O, O, U and rare earths. These elements were leeched out of the rocks of the rhyolite dyke swarm, with its high uranium content of 12 ppm compared to 7 ppm in Burstall Granite, 3.5 ppm in the metasediments, 1 ppm in quartzite, and 0.7 ppm in basic rocks. The uranium-rich fluids moved westwards from the dykes, following decreasing temperature gradient. They were obstructed in most places by a chemically inert quartzite layer, but broke through this barrier in at least two places. Then they intersected a sequence of permeable conglomerate lenses in which they deposited the largely stratabound ore body.

Description

Mary Kathleen Mine is an abandoned open cast mine with impressive mine terraces and a blue lake at the bottom. The nearby mining settlement Mary Kathleen was abandoned when the mine was closed. The site is located off Highway A2/83/Barkly Highway halfway between Mount Isa and Cloncurry. As it becomes more popular as a tourist site it is again signposted with a brown point of interest sign.

The village Mary Kathleen is older than the mine, it was first settled during the 1860s. Clem Walton and Norm McConachy discovered the uranium ores in 1954. They named the deposit after the late wife of McConachy, and later and the township was named after the mine. Prospecting and exploitation rights were sold to Rio Tinto Mining who founded Mary Kathleen Uranium Ltd to develop the mine and a service town. The town was designed by architects and built between 1956 and 1958. Even a dam and a reservoir lake named Lake Corella were constructed to provide drinking water for the town. Mine and Township were officially opened by Robert Menzies, Prime Minister of Australia and Frank Nicklin, Premier of Queensland in October 1958.

The mine was very productive, by 1963 the major supply contract had been satisfied ahead of schedule. Between 1958 and 1963 4,080 tonnes of uranium oxide were extracted from 2.9 million tonnes of ore at an average grade of 0.13%. As a result the works were closed down, most of the 1,000 inhabitants left the town an only about 80 people still lived there. But after new supply contracts with Japanese, German and American power utilities were made, the mine was reopened. In 1974 the workers returned, the town was again inhabited by 700 people, and in 1976 production began. In this second phase 4,802 tonnes of uranium oxide were produced.

After the deposit was exhausted in 1981, the mine and mill were dismantled and the tailings rehabilitated. In 1984 the mine became the site of Australia's first major rehabilitation project of an uranium mine, which was completed at the end of 1985. The village was abandoned after all works were completed, but it became not a ghost town like so many other abandoned mining settlements. All the buildings were completely removed, probably a part of the rehabilitation project, only the roads remained. In other words, you can see exactly where the settlement has been on Google Maps satellite view, but the buildings have vanished. There are paved roads, building lots without houses, even the old town square with the basements of supermarkets and other shops and a fountains can be seen. While the town is gone the Lake Corella still exists.

The site became well known for mineral collecting, which is called fossicking in Australia. Numerous relics are on display in the Mary Kathleen Memorial Park and Museum in Cloncurry. There are various tour operators, which offer day trips to the site. If you go on your own, you should be careful, despite the awarded rehabilitation project, the seepage of radioactive waters is much higher than initially predicted. The radioactive waste has seeped into former evaporation ponds as well as local drainage systems. The radioactivity is strong enough to have caused widespread death of native vegetation, the problem has not yet been resolved. Also you should be aware that the minerals you collect might be radioactive.