Towards a regolith mineralogy map of the Australian continent: a feasibility study in the Darling-Curnamona-Delamerian region

2021 ◽  
Author(s):  
P. de Caritat ◽  
U. Troitzsch
Keyword(s):  
Feasibility Study ◽  
Goodness Of Fit ◽  
Size Fraction ◽  
Xrd Analysis ◽  
Weight Percent ◽  
Bulk Sample ◽  
Deep Dive ◽  
Quantitative Mineralogy ◽  
Australian Continent ◽  
Mineral Identification

Bulk quantitative mineralogy of regolith is a useful indicator of lithological precursor (protolith), degree of weathering, and soil properties affecting various potential landuse decisions. To date, no national-scale maps of regolith mineralogy are available in Australia. Catchment outlet sediments collected over 80% of the continent as part of the National Geochemical Survey of Australia (NGSA) afford a unique opportunity to rapidly and cost-effectively determine regolith mineralogy using the archived sample material. This report releases mineralogical data and metadata obtained as part of a feasibility study in a selected pilot area for such a national regolith mineralogy database and atlas. The area chosen for this study is within the Darling-Curnamona-Delamerian (DCD) region of southeastern Australia. The DCD region was selected as a ‘deep-dive’ data acquisition and analysis by the Exploration for the Future (2020-2024) federal government initiative managed at Geoscience Australia. One hundred NGSA sites from the DCD region were prepared for X-Ray Diffraction (XRD) analysis, which consisted of qualitative mineral identification of the bulk samples (i.e., ‘major’ minerals), qualitative clay mineral identification of the <2 µm grain-size fraction, and quantitative analysis of both ‘major’ and clay minerals of the bulk sample. The identified mineral phases were quartz, plagioclase, K-feldspar, calcite, dolomite, gypsum, halite, hematite, goethite, rutile, zeolite, amphibole, talc, kaolinite, illite (including muscovite and biotite), palygorskite (including interstratified illite-smectite and vermiculite), smectite (including interstratified illite-smectite), vermiculite, and chlorite. Poorly diffracting material (PDM) was also quantified and reported as ‘amorphous’. Mineral identification relied on the EVA® software, whilst quantification was performed using Siroquant®. Resulting mineral abundances are reported with a Chi-squared goodness-of-fit between the actual diffractogram and a modelled diffractogram for each sample, as well as an estimated standard error (esd) measurement of uncertainty for each mineral phase quantified. Sensitivity down to 0.1 wt% (weight percent) was achieved, with any mineral detection below that threshold reported as ‘trace’. Although detailed interpretation of the mineralogical data is outside the remit of the present data release, preliminary observations of mineral abundance patterns suggest a strong link to geology, including proximity to fresh bedrock, weathering during sediment transport, and robust relationships between mineralogy and geochemistry. The mineralogical data generated by this study are presented in Appendix A of this report and are downloadable as a .csv file. Mineral abundance or presence/absence maps are shown in Appendices B and C to document regional mineralogical patterns.

Towards a heavy mineral map of the Australian continent: a feasibility study

2020 ◽  
Author(s):  
Patrice de Caritat ◽  
Brent McInnes ◽  
Stephen Rowins
Keyword(s):  
Mineral Exploration ◽  
Size Fraction ◽  
Pilot Project ◽  
Resource Discovery ◽  
Heavy Minerals ◽  
Continental Scale ◽  
Quantitative Mineralogy ◽  
Geological Processes ◽  
Isotopic Analyses ◽  
Australian Continent

Heavy minerals (HMs) are minerals with a specific gravity greater than 2.9 g/cm3. They are commonly highly resistant to physical and chemical weathering, and therefore persist in sediments as lasting indicators of the (former) presence of the rocks they formed in. The presence/absence of certain HMs, their associations with other HMs, their concentration levels, and the geochemical patterns they form in maps or 3D models can be indicative of geological processes that contributed to their formation. Furthermore trace element and isotopic analyses of HMs have been used to vector to mineralisation or constrain timing of geological processes. The positive role of HMs in mineral exploration is well established in other countries, but comparatively little understood in Australia. Here we present the results of a pilot project that was designed to establish, test and assess a workflow to produce a HM map (or atlas of maps) and dataset for Australia. This would represent a critical step in the ability to detect anomalous HM patterns as it would establish the background HM characteristics (i.e., unrelated to mineralisation). Further the extremely rich dataset produced would be a valuable input into any future machine learning/big data-based prospectivity analysis. The pilot project consisted in selecting ten sites from the National Geochemical Survey of Australia (NGSA) and separating and analysing the HM contents from the 75-430 µm grain-size fraction of the top (0-10 cm depth) sediment samples. A workflow was established and tested based on the density separation of the HM-rich phase by combining a shake table and the use of dense liquids. The automated mineralogy quantification was performed on a TESCAN® Integrated Mineral Analyser (TIMA) that identified and mapped thousands of grains in a matter of minutes for each sample. The results indicated that: (1) the NGSA samples are appropriate for HM analysis; (2) over 40 HMs were effectively identified and quantified using TIMA automated quantitative mineralogy; (3) the resultant HMs’ mineralogy is consistent with the samples’ bulk geochemistry and regional geological setting; and (4) the HM makeup of the NGSA samples varied across the country, as shown by the mineral mounts and preliminary maps. Based on these observations, HM mapping of the continent using NGSA samples will likely result in coherent and interpretable geological patterns relating to bedrock lithology, metamorphic grade, degree of alteration and mineralisation. It could assist in geological investigations especially where outcrop is minimal, challenging to correctly attribute due to extensive weathering, or simply difficult to access. It is believed that a continental-scale HM atlas for Australia could assist in derisking mineral exploration and lead to investment, e.g., via tenement uptake, exploration, discovery and ultimately exploitation. As some HMs are hosts for technology critical elements such as rare earth elements, their systematic and internally consistent quantification and mapping could lead to resource discovery essential for a more sustainable, lower-carbon economy.

Effect of Cobalt Content on the Structural Properties of Zirconia Prepared by Sol-Gel Method

2020 ◽  
Vol 1000 ◽  
pp. 227-232
Author(s):  
Nurhayati Indah Ciptasari ◽  
Adri Nora ◽  
Lutviasari Nuraini ◽  
Lusiana ◽  
Nono Darsono ◽  
...  
Keyword(s):  
Structural Properties ◽  
Sol Gel ◽  
Cobalt Content ◽  
Secondary Phase ◽  
Xrd Analysis ◽  
Weight Percent ◽  
Sem Images ◽  
Monoclinic Crystal ◽  
Gel Method ◽  
Sol Gel Method

Zirconia (ZrO2) powders doped with cobalt were prepared by sol-gel method using inorganic salt of zirconium (IV) chloride (ZrCl4) as precursor. The amount of cobalt was varied in the range of 4–16% weight percent to study the effect to structural properties. X-ray diffraction (XRD) analysis suggested the resulting phases were zirconium oxide (Baddeleyite) with monoclinic crystal system along with cobalt oxide as secondary phase. The increasing cobalt content caused the XRD peaks to shift into lower angle due to substitution of Zr atom to smaller Co atom in crystal lattice. Scanning electron microscope (SEM) images showed the samples with higher Co content had smoother surface. Generally, the microstructures of Co doped zirconia powders consisted of large agglomerates with small particles on the surface.

Synthesis and Characterization of Strontium-Doped Lanthanum Cobaltite Cathode Material Prepared by a Modified Combined Complexing Method

2013 ◽  
Vol 701 ◽  
pp. 131-135 ◽  
Author(s):  
Abdullah Abdul Samat ◽  
Mohd Azlan Mohd Ishak ◽  
Hamidi Abd Hamid ◽  
Osman Nafisah
Keyword(s):  
Cathode Material ◽  
Ethylenediaminetetraacetic Acid ◽  
Perovskite Phase ◽  
Chelating Agent ◽  
Xrd Analysis ◽  
Bulk Sample ◽  
Potential Candidate ◽  
X Ray Diffraction ◽  
Lanthanum Cobaltite

A potential candidate for intermediate temperature solid oxide fuel cell (IT-SOFC) cathode material which is strontium-doped lanthanum cobaltite, La0.6Sr0.4CoO3-α (LSCO) has been synthesized by a complexing method. Citric acid (CA) and ethylenediaminetetraacetic acid (EDTA) were used as a combined chelating agent and ethylene glycol (EG) was employed as surfactant. The obtained powder was characterized by thermogravimetric analysis (TGA), X-ray diffraction (XRD) analysis and scanning electron microscopy (SEM). TGA results showed the thermal decomposition of the precursor gel was completed at 700 °C. A single perovskite phase of LSCO with cubic structure was obtained at calcination temperature of 1000 °C with heating/cooling rate of 10 °C min-1 as confirmed by XRD analysis. SEM result revealed that the morphology of the powder was spherical in shape with diameter ranging from 250 to 650 nm. Apparently, the bulk sample consists of almost homogeneous and identical particles.

Thermogravimetry/evolved water analysis (TG/EWA) combined with XRD for improved quantitative whole-rock analysis of clay minerals in sandstones

Clay Minerals ◽  
1995 ◽  
Vol 30 (1) ◽  
pp. 27-38 ◽  
Author(s):  
D. M. Thornley ◽  
T. J. Primmer
Keyword(s):  
Clay Minerals ◽  
Clay Mineral ◽  
Water Analysis ◽  
Infrared Detector ◽  
Size Fraction ◽  
Xrd Analysis ◽  
X Ray Diffraction ◽  
Northern North Sea ◽  
Rock Analysis

AbstractCurrent methods of quantitative whole-rock clay mineral analysis of sandstones often provide little more than an estimate of clay mineral abundances, especially where the total clay mineral content is <10 wt% of the sandstone. More accurate determinations of clay mineral abundance in the whole rock can be made by combining thermogravimetry/evolved water analysis (TG/EWA) and X-ray diffraction (XRD) data. The TGA/EWA system incorporates a purpose built thermobalance linked to a water specific infrared detector which is used to measure quantitatively the clay mineral dehydroxylation water evolved from the whole rock when heated from 250°C to 900°C. This gives a measure of the total hydroxyl content of the clay minerals in the whole rock which, when combined with XRD analysis of a separated clay size-fraction, enables individual clay mineral abundances in the whole-rock sample to be determined. Results on artificial sand/clay mineral mixtures prepared with known amounts of different clay minerals (chlorite, illite and kaolinite) show that the accuracy of the combined method is most influenced by the accuracy of the XRD data. Errors associated with TG/EWA were found to be negligible by comparison. A case study is included in which the technique has been used to determine accurately the illite abundance in the Magnus Sandstone Reservoir, Northern North Sea.

Effect of Aluminising on the Hot Corrosion Resistance of Nickel-Chromium Alloys

2006 ◽  
Vol 514-516 ◽  
pp. 505-509 ◽  
Author(s):  
César A.C. Sequeira ◽  
Fernand D.S. Marquis
Keyword(s):  
Corrosion Resistance ◽  
Molten Salt ◽  
Hot Corrosion ◽  
Xrd Analysis ◽  
Weight Percent ◽  
Test Results ◽  
Nickel Chromium ◽  
Chromium Alloys ◽  
Nial Phase ◽  
Cyclic Corrosion

The effects of aluminising on the hot corrosion resistance of two nickel-chromium alloys containing 10 and 30 weight percent chromium, respectively, were examined. The Ni/Cr specimens were aluminised by pack cementation in Ar and underwent cyclic hot corrosion testing in Na2SO4- NaCl molten salt. XRD analysis indicated that a NiAl phase formed between the coating layer and substrate. Cyclic hot corrosion test results indicated that the effects of aluminising are more pronounced in the case of the 10 % Cr than in the case of 30 % Cr. The ductile NiAl phase suppressed the potential for crack initiation during thermal cycling of the 10 % Cr specimens, and reinforced the hot cyclic corrosion resistance in molten salt for the 30 % Cr specimens.

scholarly journals Morphological, microstructural and magnetic characteristics of electrodeposited Ni-Fe-W-Cu alloy powders

2020 ◽  
Vol 52 (1) ◽  
pp. 109-121 ◽  
Author(s):  
Miroslav Spasojevic ◽  
Sinisa Randjic ◽  
Aleksa Maricic ◽  
Tomislav Trisovic ◽  
Milica Spasojevic
Keyword(s):  
Xrd Analysis ◽  
Weight Percent ◽  
Mean Value ◽  
Ammonium Citrate ◽  
Magnetic Characteristics ◽  
Cu Alloy ◽  
Short Range Ordering ◽  
Powder Particles ◽  
Current Densities ◽  
The Mean

Nanostructured Ni-Fe-W-Cu alloy powders were electrodeposited from an alkaline ammonium citrate solution on a titanium cathode. Powder particles were dendrite- and cauliflower-shaped. The dendritic particles had a high density of branches made up of interconnected globules. XRD analysis showed that the powder contained an amorphous matrix and FCC nanocrystals of the solid solution of Fe, W and Cu in Ni. As the deposition current density increased, the mean nanocrystal size decreased, and the mean value of internal microstrain and the total weight percent of Fe and Ni in the alloy increased. The powders deposited at higher current densities exhibited higher magnetization. During annealing at temperatures up to 460?C, the powders underwent short-range ordering, which caused an increase in magnetization, whereas at temperatures above 460?C, the magnetization decreased due to the formation of large FCC crystalline grains.

scholarly journals The within-day behaviour of 6 minute rainfall intensity in Australia

2011 ◽  
Vol 15 (8) ◽  
pp. 2561-2579 ◽  
Author(s):  
A. W. Western ◽  
B. Anderson ◽  
L. Siriwardena ◽  
F. H. S. Chiew ◽  
A. Seed ◽  
...  
Keyword(s):  
Goodness Of Fit ◽  
Rainfall Intensity ◽  
Daily Rainfall ◽  
Distribution Functions ◽  
Average Intensity ◽  
Fit Statistics ◽  
Australian Continent ◽  
Generation Mechanisms ◽  
Parameter Values ◽  
Two Parameter

Abstract. The statistical behaviour and distribution of high-resolution (6 min) rainfall intensity within the wet part of rainy days (total rainfall depth >10 mm) is investigated for 42 stations across Australia. This paper compares nine theoretical distribution functions (TDFs) in representing these data. Two goodness-of-fit statistics are reported: the Root Mean Square Error (RMSE) between the fitted and observed within-day distribution; and the coefficient of efficiency for the fit to the highest rainfall intensities (average intensity of the 5 highest intensity intervals) across all days at a site. The three-parameter Generalised Pareto distribution was clearly the best performer. Good results were also obtained from Exponential, Gamma, and two-parameter Generalized Pareto distributions, each of which are two parameter functions, which may be advantageous when predicting parameter values. Results of different fitting methods are compared for different estimation techniques. The behaviour of the statistical properties of the within-day intensity distributions was also investigated and trends with latitude, Köppen climate zone (strongly related to latitude) and daily rainfall amount were identified. The latitudinal trends are likely related to a changing mix of rainfall generation mechanisms across the Australian continent.

scholarly journals The within-day behaviour of 6 minute rainfall intensity in Australia

2011 ◽  
Vol 8 (2) ◽  
pp. 3189-3231
Author(s):  
A. W. Western ◽  
B. Anderson ◽  
L. Siriwardena ◽  
F. H. S. Chiew ◽  
A. Seed ◽  
...  
Keyword(s):  
Goodness Of Fit ◽  
Rainfall Intensity ◽  
Daily Rainfall ◽  
Distribution Functions ◽  
Average Intensity ◽  
Fit Statistics ◽  
Australian Continent ◽  
Generation Mechanisms ◽  
Parameter Values ◽  
Two Parameter

Abstract. The statistical behaviour and distribution of high-resolution (6 min) rainfall intensity within the wet part of rainy days (total rainfall depth >10 mm) is investigated for 42 stations across Australia. This paper compares nine theoretical distribution functions (TDFs) in representing these data. Two goodness-of-fit statistics are reported: the Root Mean Square Error (RMSE) between the fitted and observed within-day distribution; and the efficiency of prediction of the highest rainfall intensities (average intensity of the 5 highest intensity intervals). The three-parameter Generalised Pareto distribution was clearly the best performer. Good results were also obtained from Exponential, Gamma, and two-parameter Generalized Pareto distributions, each of which are two parameter functions, which may be advantageous when predicting parameter values. Results of different fitting methods are compared for different estimation techniques. The behaviour of the statistical properties of the within-day intensity distributions was also investigated and trends with latitude, Köppen climate zone (strongly related to latitude) and daily rainfall amount were identified. The latitudinal trends are likely related to a changing mix of rainfall generation mechanisms across the Australian continent.

Quantitative XRD bulk and clay mineralogical determination of paleosol sections of Unayzah and Basal Khuff clastics in Saudi Arabia

2012 ◽  
Vol 27 (2) ◽  
pp. 126-130 ◽  
Author(s):  
Shouwen Shen ◽  
Syed R. Zaidi ◽  
Bader A. Mutairi ◽  
Ahmed A. Shehry ◽  
Husin Sitepu ◽  
...  
Keyword(s):  
Clay Minerals ◽  
Clay Mineral ◽  
Mixed Layer ◽  
Size Fraction ◽  
Xrd Analysis ◽  
Ratio Method ◽  
Type I ◽  
Rock Formations ◽  
Refinement Method

Quantitative X-ray diffraction (XRD) analysis is performed on 172 samples mainly containing paleosol sections of Unayzah and Basal Khuff clastics taken from the core of one well drilled by Saudi Aramco. Quantitative XRD bulk mineralogical determination is achieved using the Rietveld refinement method whereas quantitative XRD clay mineralogical determination of clay-size fraction is obtained using the reference intensity ratio method. The XRD results indicate that the samples from paleosol sections consist mainly of quartz and feldspar (microcline and albite) as framework constituents. Cement minerals include dolomite, hematite, anhydrite, siderite, gypsum, calcite, and pyrite. Clay minerals are important constituents in paleosols. The XRD results show that clay minerals in the samples are illite, mixed-layer illite/smectite, kaolinite, and chlorite. No discrete smectite is present in the samples. The clay mineral associations in these samples of paleosol sections can be classified into three types: Type I predominantly consists of illite and a mixed layer of illite/smectite; Type II of kaolinite; and Type III of illite and a mixed layer of illite/smectite, but also significant amounts of kaolinite. The change of clay mineral association type with sample depth can indicate the change of paleoclimate and paleoenvironment. For example, kaolinite usually forms under strongly leaching conditions such as abundant rainfall, good drainage, and acid waters. Therefore, XRD mineralogical data of paleosol sections are important for petroleum geologists to study paleoclimate and paleoenvironment and to predict the reservoir quality of the associated rock formations.

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