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  • The deposits of heavy mineral sands along the East Coast of Australia are being investigated primarily to determine their content of monazite. These deposits contain most of the known world reserves of zircon and rutile for which they are being exploited at various localities. Monazite, a phosphate of cerium, lanthanum, praseodymium and other rare earths, with thorium silicate, is utilised commercially as a source of cerium and of thorium. In this investigation, the thorium content on the monazite is being determined on the basis of its radioactivity. Two deposits in the Tweed-Fingal area were examined. The geology of the area, methods of testing, and the results of the investigation are discussed in this report.

  • 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.

  • An outcrop of marmatite (zinc sulphide) has been located within the boundaries of E.P.L.26 held by New Guinea Goldfields Limited. The following notes describe the outcrop as discovered and certain recommendations are made to assist in the evaluation of the outcrop as a base-metal orebody. Other recommendations are made embracing other known occurrences of base-metal sulphides in the Territory of Papua and New Guinea.

  • Report on the method and findings of the beach sands investigation in the area between ML180 and DC22, Broadbeach to North Burleigh. Estimates of the quantities and grades of heavy mineral concentrates, the quantities of overburden, and the quantities of each of the heavy minerals are tabulated.

  • Raman spectroscopy has been used for the identification of both common and uncommon minerals in melt inclusions in Group-I kimberlites from Siberia, Canada, SW Greenland and South Africa. The melt inclusions all contained high abundances of alkali-Ca carbonates, with varying proportions of cations, and Na-Ca-Ba sulphates. However, no hydrated carbonates or sulphates were detected in melt inclusions from the Udachnaya-East kimberlite which is in agreement with its dry matrix mineralogy. In contrast, the melt inclusions in kimberlites from Canada, South Africa and SW Greenland were found to contain bassanite, pirssonite, and hydromagnesite suggesting that greater amounts of water were present in their residual magmas. This suggests that enrichment in alkali carbonates and sulphates is widespread across a range of Group-I kimberlites and implies that they commonly have an alkali-, and sulphur-rich residual kimberlite melt.

  • A test survey was made with a Radore Equipment over three mineralised areas in Tasmanian. The investigations were made in January, 1955 for the purpose of comparing the performance of the Radore equipment with that of lower-frequency electromagnetic equipment previously used successfully over the same areas. The results show that although some very weak indications were recorded by the Radore equipment, it has not been possible to correlate these satisfactorily with the know mineralisation. Moreover, it is difficult to distinguish indications that may possibly be due to mineralisation from apparent indications that are undoubtedly due to irregularities in topography.

  • A number of Paleoproterozoic layered mafic-ultramafic intrusions in the central part of the Halls Creek Orogen of East Kimberley, Western Australia, have been explored for platinum-group elements (PGE), chromium, nickel, copper, cobalt and gold. Here we report on the halogen geochemistry of apatite and biotite in a number of these intrusions. Interstitial apatite is ubiquitous in these intrusions and, in most samples, tends to be relatively enriched in F- and OH-endmembers and relatively poor in Cl (< 20 mole %). Fluorapatite occurs in the more evolved igneous rocks and in marginal samples that apparently have been contaminated by metamorphic country rock. Cl/F ratios generally increase with bulk rock molar Mg/(Mg + Fe) ratios, as observed in other intrusions. Only a few samples show Cl-enrichment as high as that seen in the Stillwater and Bushveld complexes beneath the major stratabound PGE deposits. The most Cl-rich compositions observed occur in the upper part of the Springvale intrusion, where it is associated with troctolite, and in a single sample from the McIntosh intrusion. For the former intrusion, it is suggested that volatiles migrating out of the lower part of the mafic stratigraphy stabilized olivine at the expense of pyroxene. Associated biotite tends to be low in both Cl and F, containing no more than 10 mole % of these components. It is concluded that the East Kimberley intrusions contained a low to moderate volatile component that, during the combined processes of crystallization, degassing and fractionation of interstitial halogen-bearing minerals, was able to produce a late, mobile interstitial silicate liquid or volatile-rich fluid phase of variable Cl/F content that gave rise to most of the observed variations within any given intrusion. The exceptions include some marginal samples that appear to have been affected by country rocks, either during emplacement (assimilation) or during later metamorphism. The generally low Cl/F ratio of apatite, the lack of primary amphibole and the high background sulfur concentrations of the East Kimberley intrusions suggest that these magmas were relatively dry. The possible development of high-grade, PGE-enriched horizons by late-stage hydrothermal processes that could have mobilized significant amounts of the PGE and sulfur is considered to be of low potential.

  • The Crater Prospect is situated about 4 miles south-south-east of White's workings and 1 mile north-east of the junction of Batchelor Road and the Darwin-Birdum railway line. It is the name assigned to a type area of an extensive radioactive bed of conglomerate. Low grade but wide-spread radioactivity was discovered by R.S. Matheson and D.F. Dyson (geophysicists) in June 1951, while prospecting along the sedimentary beds out-cropping immediately south of the Rum Jungle granite on the south-side of Giant's Reef fault, and on the south side of another major parallel fault. Geiger-Muller traverses along the strike of a grit-conglomerate horizon away from the Crater prospect revealed that the radioactivity extends westwards for 1.5 miles and for half a mile to the east. The radioactivity, which was confined to the conglomerate, was low-grade and discontinuous over this distance of 2 miles. The Crater Prospect, which can be regarded as a type locality, was geologically mapped by the writer on a scale of 200 feet to one inch after the area had been radiometrically contoured, and the plan accompanies this report (Plate 1). [The geology and structure of the prospect, nature of the radioactivity, and prospecting recommendations are discussed].

  • Global-scale mapping of surface mineralogy is now becoming possible using remote hyperspectral sensing technologies. Global-scale mineral maps have now been generated for Mars using thermal infrared hyperspectral data collected from the Mars-orbiting Thermal Emission Spectrometer (TES- http://jmars.asu.edu/data/), including maps of feldspar, pyroxene, olivine and quartz contents. Other mineral maps of Mars are now being assembled using the recently launched Compact Reconnaissance Imaging Spectrometer (CRISM - http://crism.jhuapl.edu/), including sulphates, kaolinite, illite/muscovite, chlorites, carbonate and water (www.lpi.usra.edu/meetings/7thmars2007/pdf/3270.pdf). In contrast, even though mapping the mineralogy of the Earth's land surface can improve understanding and management of Earth's resources, including: - monitoring of soils (acid sulphate soils, salinity, soils loss and soil carbon); - better characterisation of regolith materials (e.g. transported versus in situ); - discovery of new mineral deposits using alteration vectors; and - more accurate environmental assessments during resource exploitation (baseline mapping, monitoring and closure)

  • Raman spectroscopy has been an invaluable method for the non-destructive analysis of fluid inclusions for over 30 years1 and since then it has also been applied to the study of melt inclusions2. While the analysis of gas species in these inclusions is relatively straight forward, the identification of stable and metastable solid phases in inclusions is more challenging due to the limited availability of reference Raman spectra for some minerals. Some examples of inclusions with challenging Raman spectra are discussed below.