Application of mineral magnetism to describe profile development of toposequences of a sedimentary soil in south-eastern Australia

Soil Research ◽  
2001 ◽  
Vol 39 (5) ◽  
pp. 927 ◽  
Author(s):  
R. H. Crockford ◽  
I. R. Willett
Keyword(s):  
Particle Size ◽  
Grain Size ◽  
Magnetic Susceptibility ◽  
Magnetic Particles ◽  
Size Range ◽  
The Other ◽  
Particle Sizes ◽  
Mineral Magnetism ◽  
Particle Size Range ◽  
Eastern Australia

Mineral magnetism and chemical properties of soil profiles across a valley with an erosion gully in a Yellow Dermosol sedimentary soil suggest that the magnetic profile resulted from a combination of alluviation and pedogenesis. The concentration of soil magnetic minerals in a range of particle sizes (3.36–2 mm to <2 μm) diminished from the surface downwards to a minimum (referred to as layer P), then increased to high values (layer H), after which it decreased to bed rock level at the base layer. It is proposed that the H layer was the surface of a buried soil, and that the ferrimagnetic mineral through the profiles was dominantly maghemite, formed by fire enhancement. The magnetic pattern of the profiles compressed as the soil became shallower up-slope, from 3 m in depth at the lowest site to 0.7 m at a site 40 m up-slope. Above this site the high susceptibility H layer was absent, which is consistent with the H layer being an earlier soil surface. Except for the profile at the very top of the slope (depth of 0.63 m), the magnetic grain size did not vary with depth. In the P layers, there was a greater proportion of paramagnetic minerals than in the other layers. The changes in magnetic susceptibility through the profiles were influenced by ferrimagnetic, paramagnetic, and canted anti-ferromagnetic material. For all depths in all profiles the magnetic susceptibility changed consistently through the particle size range, decreasing from the larger sizes to the 10–20 m size then increasing slightly to the smallest size (<2 μm). The mean magnetic grain size also decreased through the particle size range. Magnetic particles of 3 concentration levels were extracted by a hand magnet from the 4 largest particle sizes and showed the same magnetic-particle size relationships, for both mass susceptibility and magnetic grain size, as the other particle sizes. This showed that the proportion of highly magnetic particles effectively determined the susceptibility and magnetic grain size features of the bulk samples of each particle size class. The particle size/magnetic susceptibility pattern described in this paper occurs in all sedimentary soils and derived river sediments studied in this part of Australia. However, soils and sediments of granitic origin have an inverse pattern. These differences are attributed to pedogenic and geomorphological process. The difficulties in using mineral magnetic properties as a means of sourcing mobile sediments in catchments are discussed.

DISSOLUTION OF TRIOCTAHEDRAL LAYER SILICATES BY AMMONIUM OXALATE, SODIUM DITHIONITE–CITRATE–BICARBONATE, AND POTASSIUM PYROPHOSPHATE

1972 ◽  
Vol 52 (1) ◽  
pp. 19-26 ◽  
Author(s):  
M. A. ARSHAD ◽  
R. J. ST. ARNAUD ◽  
P. M. HUANG
Keyword(s):  
Particle Size ◽  
Organic Matter ◽  
Size Range ◽  
Ammonium Oxalate ◽  
Size Fraction ◽  
Sodium Dithionite ◽  
Particle Sizes ◽  
Particle Size Range ◽  
Layer Silicates ◽  
Chemical Extractants

The effects of NH4-oxalate (pH 3), Na–dithionite–citrate–bicarbonate (pH 7.3), and K-pyrophosphate (pH 10) on various size fractions of biotite, chlorite, muscovite, and illite minerals were investigated. The data showed that the release of mineral cations by the three chemical extractants increased with decreasing particle sizes. The dissolution of layer silicates was slight and gradual in the particle size range of 100–5 μ, increased considerably for 5–2 μ and markedly below 2 μ. In general, NH4-oxalate dissolved the maximum percentage of Fe, Mg, and Al, and K-pyrophosphate extracted the least amount. Approximately 18.8% of original Fe, 15.5% of Mg, and 11.3% of Al were extracted from 0.2–0.08 μ-size biotite by the oxalate procedure. The corresponding values for the same size fraction of chlorite were: 23.2% Fe, 18.5% Mg, and 13.5% Al. In view of the data obtained it is suggested that the use of NH4-oxalate as an extractant for amorphous Fe and Al may have limitations for soils containing trioctahedral minerals. Instead, K-pyrophosphate, which has little effect on crystalline minerals and also has the advantage of extracting organic matter-complexed Fe and Al, may be more suitable.

Comparison of Silica Sand Properties from Kandal Province, Cambodia and Tapah, Perak, Malaysia and Characterization of Soda Lime Silicate Glass Produced From Cambodian Silica Sand

2013 ◽  
Vol 858 ◽  
pp. 248-253 ◽  
Author(s):  
Em Sereiratana ◽  
Khairul Anwar Bharum ◽  
S.A. Rezan ◽  
Radzali Othman ◽  
Fumitake Takahashi ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Particle Size ◽  
Melting Temperature ◽  
Size Range ◽  
Soda Lime ◽  
The Other ◽  
Silica Sand ◽  
Particle Size Range ◽  
Soaking Time ◽  
X Ray

Silica sand from Kandal province, Cambodia and Tapah Perak, Malaysia was grounded into an average micron size of 128.12 and 132.68µm. Both sands were characterized by X-ray fluorescence (XRF), X-ray Diffraction, particle Size Analysis, Differential Thermal Analysis and Thermogravimetric Analysis (DTA/TGA). Malaysian silica sand was designated SDMTP and Cambodian Silica sand as SDCK. From theanalysis, XRF showed that the major impurities in SDMTP were Al2O3, K2O and TiO2. On the other hand, SDCK had impurities of Al2O3,K2O and Na2O. DTA results from SDMTP and SDCK showedthere is an endothermic peak occurring at 572°C which can be attributed to β-quartz transformation into α-quartz. TGA for SDMTP showed that maximum weight lost was at 441°C with a weight percent (wt%) change of 0.48%. The TGA for SDCK showed a wt% change of 1.298% at temperature of 1000°C. From XRD analysis, the main phase of SDCK and SDMTP were quartz. The impurities of both sands play an important role in determining the optical and mechanical properties of the soda lime silicate (SLS) glass formed. Particle size of silica sand affects the mechanical properties such as compression, hardness, and transmittance of SLS glass. The smaller particle size would be ideal choice for glassmaking. Melting temperature, soaking time, and melt accelerant can also affect the mechanical properties of SLS glass. The best result obtained for Vickers hardness in this study was the SLS glass sample designated as Run No 12 with a value of 525.02 kg.mm-2. It had a particle size range from 500-600µm, a furnace soaking time of 4 hours at a melting temperature of 1500°C with 1.0 wt% of Sodium Chloride (NaCl) as meltingaccelerant. On the other hand, the highest compressive strength of 356.22 MPa was found in sample designated as Run No 1. It had a particle size range from 75-1800µm, a soaking time of 5 hours at a melting temperature of 1550°C with 0.5 wt% of NaCl. Lastly,the highest UV-VIS transmittance at 520 nm was obtained from sample designated as Run No 5 within the value of 84.26 %Transmittance (T). It had a particle size range of 75-1800µm, soaking time of 3 hours at a melting temperature of 1550°C with 1.5 wt% of NaCl. .

381. Sampling Efficiencies of Three Personal Aerosol Samplers within and Beyond the Inhalable Particle Size Range

2001 ◽  
Author(s):  
V. Aizenberg ◽  
P. Baron ◽  
K. Choe ◽  
S. Grinshpun ◽  
K. Willeke
Keyword(s):  
Particle Size ◽  
Size Range ◽  
Particle Size Range

scholarly journals The Moyjil site, south-west Victoria, Australia: fire and environment in a 120,000-year coastal midden — nature or people?

2018 ◽  
Vol 130 (2) ◽  
pp. 71 ◽  
Author(s):  
Jim M. Bowler ◽  
David M. Price ◽  
John E. Sherwood ◽  
Stephen P. Carey
Keyword(s):  
Magnetic Susceptibility ◽  
Strong Correlation ◽  
The Other ◽  
Last Interglacial ◽  
Human Occupation ◽  
Thermal Alteration ◽  
South West ◽  
Eastern Australia ◽  
Dark Staining ◽  
Mis 5E

At Moyjil (Point Ritchie), a cliffed site at the mouth of the Hopkins River at Warrnambool, south-eastern Australia, an erosional disconformity of Last Interglacial age on both a rock stack and the adjacent headland represents a surface of possible human occupation. Shells of edible marine molluscs occur on the disconformity, together with a distinctive population of transported stones derived from a calcrete of MIS 7 age and bearing variable dark grey to near-black colouration suggestive of fire. Experimental fire produced similar thermal alteration of calcrete. A strong correlation exists between intensity and depth of dark staining on one hand and increased magnetic susceptibility on the other. Thermal luminescence analyses of blackened stones provide ages in the MIS 5e range, 100–130 ka, consistent with independent stratigraphic evidence and contemporaneous with the age of the surface on which they lie. The distribution of fire-darkened stones is inconsistent with wildfire effects. Two hearth-like features closely associated with the disconformity provide further indications of potential human agency. The data are consistent with the suggestion of human presence at Warrnambool during the Last Interglacial.

scholarly journals Switching cyclones to increase product particle size range for ore milling circuits

2015 ◽  
Vol 48 (17) ◽  
pp. 92-97 ◽  
Author(s):  
Stefan Botha ◽  
Ian K. Craig ◽  
Johan D. le Roux
Keyword(s):  
Particle Size ◽  
Size Range ◽  
Particle Size Range ◽  
Product Particle
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