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Radium Hill |
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South Australia, SA, Australia |
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U REE
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Super Porphyry Cu and Au
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IOCG Deposits - 70 papers
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All papers now Open Access.
Available as Full Text for direct download or on request. |
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The Radium Hill uranium deposit is located near Olary in eastern South Australia, approximately 530 km northeast of Adelaide and 100 km southwest of Broken Hill lodes.
The deposit was originally discovered 1906, with some spasmodic mining that produced 350 mg of radium bromide from 95 tons of concentrates.
In 1944 exploration was commenced by the South Australian Department of Mines and in 1954 the mine commenced full-scale production, continuing operation until December 1961. Total production amounted to 0.97 Mt of ore @ a mean grade of 0.54% U308 for 855 tonnes of U308.
The concentrates also contained appreciable lanthanum, cerium, yttrium and scandium oxides.
The deposit is at the locus of concentrated igneous intrusion, where swarms of pegmatites, plug-like bodies of aplitic microgranites, and dykes and plugs of "amphibolite" intrude granitic meta-sedimentary gneisses. The mineralisation occurs in fracture or shear planes in the Palaeoproterozoic meta-sedimentary gneisses and schists with associated acid and basic dykes. The basic intrusives comprise an earlier, generally talcose and sheared, sill-like amphibolite, and a later amphibolite which crosscuts both the gneisses and lode shears. The acid intrusives include several phases of pegmatite.
The gneisses, vary in texture from a dark coloured granulitic type to one which is light coloured with feldspar banding and contain kyanite, staurolite and sillimanite. The regional structure is dome-like, but in the vicinity of the mine the dip on bedding foliation is steep. Just to the SW of the mine, the host metamorphics an intrusives are overlain by tillitic rocks of the Neoproterozoic Adelaide System.
The main uraniferous lodes are fissure-like bodies which strike at an acute angle to foliation in the country rock and are developed in zones of strong, steeply dipping shearing. They occur along the crest of a regional dome structure. Where best developed these lodes comprise a coarse association of reddish quartz, coarse bronze and finer black biotite, and segregations of iron-titanium-uranium minerals of varying coarseness and irregular distribution. Lead isotope age determinations indicate that the age of the mineralisation is 1730 Ma.
At least three sub-parallel shear sets are recognised, although some converge and bifurcate. The three principal lode shears are around 30 m apart, strike approximately NE, dip nearly vertical or only slightly SE, while those trending slightly more easterly dip at 30 to 70°SE. The lens like swellings pitching at 45°N. In addition to this main system of mineralised shears, a similar pair of near parallel lode channels occurs around a kilometre south of the main lodes also yielded some relatively high grade ore.
The lodes vary greatly in width, the maxima coinciding with intersections of the shears with the older amphibolite. The mean width is of the order of 1.25 m. The intensity of mineralisation and of uranium content is extremely variable. The lode-shears persist well beyond the limits of economic mineralisation, with extents of more than a kilometre. Mineralisation appears to be concentrated in dialtion zones where the shears-lodes change strike direction. The mineralisation was worked to depths of 300 m and intersected in drilling to more than 450 m.
The principal ore mineral is davidite, a complex titanite of iron with varying proportions of uranium and rare earths. Radium Hill davidite typically contains 9% U308, and occurs in intimate association with ilmenite, magnetite, rutile, hematite, quartz and biotite.
Within a typical lode channel, uranium is mostly concentrated centrally along the strike of the lode shears, within the larger lens-like swellings of the lodes. Lateral and local transitions into quartz-ilmeno-hematite, into quartz-biotite, into spot replaced ilmenite, and finally into sericitic shear rock. The sequence of mineralisation is as follows:
i). Replacement of sericitic shear rock along overthrust fault zones by quartz-biotite-hematite-ilmenite mineralisation;
ii). Intrusion of rare earth pegmatites (salmon pink and glassy white felspar) containing orthite and xenotime;
iii). Movement along the shears causing brecciation of the earlier bodies and their biotite alteration;
iv). Intrusion of 'new amphibolites' along faults at about this stage;
v). Introduction of clear quartz stringers containing davidite together with irregular replacements by bright red felspar. The davidite also developed extensive intergrowth with the earlier formed ilmenite-hematite complexes.
For more detail, consult the references cited below.
The most recent source geological information used to prepare this decription was dated: 2006.
This description is a summary from published sources, the chief of which are listed below.
© Copyright Porter GeoConsultancy Pty Ltd. Unauthorised copying, reproduction, storage or dissemination prohibited.
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Parkin L W, 1965 - Radium Hill uranium mine: in McAndrew J and Madigan R T (Eds.), 1965 Geology of Australian Ore Deposits Eighth Commonwealth Mining and Metallurgical Congress, Australia and New Zealand, The AusIMM, Melbourne, v1 pp 312-313
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Sprigg R C, 1953 - Radium Hill uranium deposit: in Edwards A B (Ed.), 1953 Geology of Australian Ore Deposits Fifth Empire Mining and Metallurgical Congress, Australia and New Zealand, 1953, The AusIMM, Melbourne v1 pp 528-530
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Porter GeoConsultancy Pty Ltd (PorterGeo) provides access to this database at no charge. It is largely based on scientific papers and reports in the public domain, and was current when the sources consulted were published. While PorterGeo endeavour to ensure the information was accurate at the time of compilation and subsequent updating, PorterGeo, its employees and servants: i). do not warrant, or make any representation regarding the use, or results of the use of the information contained herein as to its correctness, accuracy, currency, or otherwise; and ii). expressly disclaim all liability or responsibility to any person using the information or conclusions contained herein.
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