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  • The presence of laterite described as high-silica bauxite at Mt. Roe on Cobourg Peninsula had been reported early in this century by H.Y.L. Brown, who submitted a specimen for analysis. In the absence of information about the mineralogical composition of the rock the chemical analysis alone affords a very incomplete description of the material. It was considered that the rock might be somewhat similar to the commercially valuable high-silica bauxite which occurs in the Netherlands East Indies and Malaya. At the request of the Australian Aluminium Production Commission the writer was instructed to examine the area in the vicinity of Mounts Roe and Bedwell, and to sample and report on any accessible bodies of apparently aluminous laterite. The locality, topography, and general geology of the area are briefly described. Accounts of the laterite occurrence at Mounts Roe, Bedwell, Kura, and Victoria are given. The mineralogical character of the laterite is described.

  • This report gives an overview of the bauxite resources of Tasmania. The report provides a summary of the work, investigation, and sampling conducted between 1941 and 1949. The mode of occurrence and types of bauxite are described. A description, which includes a statement of reserves, is given of each of the eleven individual deposits.

  • Black and white 33 page booklet on elements in the Earth's crust, silicon and silicon building blocks, the 6 basic silicon structures (e.g.. tectosilicates), the influence of aluminium, silicate mineral formation and characteristics. Includes student activities. Suitable for secondary levels Years 10-12.

  • 1. Band ratio: (B6+B9/(B7+B8) Blue is low content, Red is high content (potentially includes: calcite, dolomite, magnesite, chlorite, epidote, amphibole, talc, serpentine) Useful for mapping: (1) "hydrated" ferromagnesian rocks rich in OH-bearing tri-octahedral silicates like actinolite, serpentine, chlorite and talc; (2) carbonate-rich rocks, including shelf (palaeo-reef) and valley carbonates(calcretes, dolocretes and magnecretes); and (3) lithology-overprinting hydrothermal alteration, e.g. "propyllitic alteration" comprising chlorite, amphibole and carbonate. The nature (composition) of the silicate or carbonate mineral can be further assessed using the MgOH composition product.

  • <p>This data package includes raw (Level 0) and reprocessed (Level 1) HyLogging data from 25 wells in the Georgina Basin, onshore Australia. This work was commissioned by Geoscience Australia, and includes an accompanying meta-data report that documents the data processing steps undertaken and a description of the various filters (scalars) used in the processed datasets. <p>Please note: Data can be made available on request to ClientServices@ga.gov.au

  • 1. Band ratio: B1/B4 Blue is low abundance, Red is high abundance (potentially includes carbon black (e.g. ash), magnetite, Mn oxides, and sulphides in unoxidised envornments Useful for mapping: (1) magnetite-bearing rocks (e.g. BIF); (2) maghemite gravels; (3) manganese oxides; (4) graphitic shales. Note 1: (1) and (4) above can be evidence for "reduced" rocks when interpreting REDOX gradients. Combine with AlOH group Content (high values) and Composition (high values) products, to find evidence for any invading "oxidised" hydrothermal fluids which may have interacted with reduced rocks evident in the Opaques index product.

  • 1. Band ratio: (B6+B8)/B7 Blue is low content, Red is high content (potentially includes: chlorite, epidote, jarosite, nontronite, gibbsite, gypsum, opal-chalcedony) Useful for mapping: (1) jarosite (acid conditions) - in combination with ferric oxide content (high); (2) gypsum/gibbsite - in combination with ferric oxide content (low); (3) magnesite - in combination with ferric oxide content (low) and MgOH content (moderate-high) (4) chlorite (e.g. propyllitic alteration) - in combination with Ferrous in MgOH (high); and (5) epidote (calc-silicate alteration) - in combination with Ferrous in MgOH (low).

  • At Whites Deposit, Rum Jungle, chalcopyrite-uraninite ore has been intersected in a cross-cut at a depth of 100 ft., and sampling shows a grade of 1.5 per cent. U3O8 and 4.6 per cent. Cu. over a distance along the cross-cut of 34ft; material containing an average of 0.94 per cent. U3O8 and 2.97 per cent. Cu extends over 60 ft. Uranium mineralization is known to occur over a length of 200 ft, but the average width and grade over this distance is unknown. The ore replaces flatly pitching drag-folded beds and the width of ore along the strike is expected to vary considerably. At Dysons Prospect, about 30,000 tons of autunite-bearing ore, perhaps containing 0.25 per cent. U3O8, has been indicated by drilling. Browns Prospect is similar in many ways to Whites, but no payable ore has yet been intersected. In the district as a whole leaching of copper and uranium has been extensive and favourable areas are, in many cases, covered by soil. Structural conditions are such that non-outcropping ore is likely to be found. To-date, 3,300 ft. of drilling and approximately 700 ft. of underground prospecting have been carried out in the area and the results obtained are considered highly encouraging. Extensive drilling and underground development are warranted.

  • 1. Band ratio: (B5+B7)/B6 Blue is low abundance, Red is high abundance potentially includes: phengite, muscovite, paragonite, lepidolite, illite, brammalite, montmorillonite, beidellite, kaolinite, dickite Useful for mapping: (1) exposed saprolite/saprock (2) clay-rich stratigraphic horizons; (3) lithology-overprinting hydrothermal phyllic (e.g. white mica) alteration; and (4) clay-rich diluents in ore systems (e.g. clay in iron ore). Also combine with AlOH composition to help map: (1) exposed in situ parent material persisting through "cover" which can be expressed as: (a) more abundant AlOH content + (b) long-wavelength (warmer colour) AlOH composition (e.g. muscovite/phengite).