Properties of iron oxides in red Oxisols and red Ultisols as affected by rainfall and soil parent material

Soil Research ◽  
2006 ◽  
Vol 44 (1) ◽  
pp. 63 ◽  
Author(s):  
P. Trakoonyingcharoen ◽  
I. Kheoruenromne ◽  
A. Suddhiprakarn ◽  
R.J. Gilkes
Keyword(s):  
Iron Oxides ◽  
Crystal Size ◽  
Tropical Soils ◽  
Parent Material ◽  
Line Broadening ◽  
X Ray Diffraction ◽  
Parent Materials ◽  
Soil Parent Material ◽  
Al Substitution ◽  
Aluminum Substitution

Tropical soils developed from various parent materials and under various rainfalls were analysed to identify whether these environmental factors influence the properties of the iron oxides. Iron contents of the soils range from 5 to 134 g/kg, with hematite and goethite being the major secondary iron minerals. Hematite is the dominant iron oxide in all soils developed on limestone irrespective of rainfall, whereas for other parent materials the relative abundance of goethite tends to increase with rainfall. Aluminum substitution in goethite and hematite ranges from 13 to 21 mol% and 7 to 15 mol%, respectively. The mole% Al substitution in hematite is about half the level for goethite in the same soil. Crystal size estimated from X-ray diffraction line broadening ranges from 12 to 47 nm for goethite and from 15 to 44 nm for hematite. Similar sizes were obtained by electron microscopy. The properties of the iron oxides did not vary systematically with parent material or rainfall and are similar to those described by other workers for red tropical soils on diverse parent materials.

Iron oxides in tropical soils on various parent materials

Clay Minerals ◽  
2007 ◽  
Vol 42 (4) ◽  
pp. 437-451 ◽  
Author(s):  
W. Wiriyakitnateekul ◽  
A. Suddhiprakarn ◽  
I. Kheoruenromne ◽  
M. N. Smirk ◽  
R. J. Gilkes
Keyword(s):  
Iron Oxides ◽  
Crystal Size ◽  
Tropical Soils ◽  
Parent Materials ◽  
Fe Oxides ◽  
Al Substitution ◽  
Cell Dimensions ◽  
Basaltic Soils ◽  
Aluminium Substitution ◽  
Unit Cell Dimensions

AbstractTwenty nine Fe oxide concentrates of Thai soils formed on basalt, sandstone, shale/limestone and granite were investigated. Goethite and hematite are relatively more abundant in granitic and basaltic soils, respectively. Values of Feo/Fed range from 0.01 to 0.28 indicating that free Fe oxides are mostly crystalline.There are no systematic differences in unit-cell dimensions for goethite and hematite in soils on different parent materials. Mean crystallite dimensions calculated from the 110 reflections are greater for hematite than for goethite. Aluminium substitution varies from 8 to 24 mole% for goethite and from 4 to 17 mole% for hematite. The dehydroxylation temperature for goethite ranges from 285ºC to 320ºC. The goethite in basaltic soils has a smaller crystal size and Al substitution, as well as a lower dehydroxylation temperature, compared to soils on other parent materials. The dehydroxylation temperature of goethite is positively related to Al substitution (R = +0.58), MCD110 (R = +0.49) and Ald (R = +0.53). The Mn, Ni, Cr, V and P in these soils occur in Fe oxides rather than as discrete minerals.

Properties of iron-oxides from red soils derived from volcanic tuff in West Java

Soil Research ◽  
1994 ◽  
Vol 32 (4) ◽  
pp. 781 ◽  
Author(s):  
BH Prasetyo ◽  
RJ Gilkes
Keyword(s):  
Iron Oxide ◽  
Iron Oxides ◽  
Crystal Size ◽  
Mean Value ◽  
Line Broadening ◽  
West Java ◽  
Volcanic Tuff ◽  
Red Soils ◽  
Al Substitution ◽  
Aluminium Substitution

The properties of iron oxide concentrates of Oxisols and Alfisols on volcanic tuff in West Java, Indonesia, were studied by XRD,TGA, TEM and chemical analysis.Goethite and hematite are the co-dominant iron oxides and are present in all samples. Iron content of the soils (dithionite-soluble Fe) ranges from 6.0 to 15.4%. Aluminium substitution in goethite and hematite ranges between 11 and 26 mol% and 0 and 9 mol% respectively. The Al substitution in hematite increases at about half the rate for goethite within the same samples. Crystal size of goethite and hematite was measured from line broadening of the 110 reflections and ranges between 7 and 18 nm for goethite with a mean value of 10 nm and between 7 and 28 nm for hematite with a mean value of 18 nm. The dehydroxylation temperature of goethite is in the range 290-320 �C and is linearly related to Al substitution by the equation y = 280 + 1.53x, (R(2) = 0.53). The goethite and hematite in these Indonesian soils are very similar to these minerals in tropical and Mediterranean soils from other regions.

THE NATURE OF SMECTITES IN SOME FINE TEXTURED LACUSTRINE PARENT MATERIALS IN SOUTHERN SASKATCHEWAN

1984 ◽  
Vol 64 (4) ◽  
pp. 481-494 ◽  
Author(s):  
A. R. MERMUT ◽  
K. GHEBRE-EGZIABHIER ◽  
R. J. St. ARNAUD
Keyword(s):  
Chemical Composition ◽  
Clay Fraction ◽  
Parent Material ◽  
X Ray Diffraction ◽  
Average Chemical Composition ◽  
Parent Materials ◽  
Soil Parent Material ◽  
Composition Formula ◽  
Soil Complex ◽  
Fine Clay

Detailed mineralogy and chemistry of the clay fraction of five glacio-lacustrine deposits and of one Cretaceous marine shale (Ashville) were studied. Fine clay separates (< 0.2 μm) of the five parent materials were predominantly smectite with an average chemical composition:[Formula: see text]X-ray diffraction, dehydration, infrared, and chemical analyses, and the Greene-Kelly test showed that the smectite was an iron rich montmorillonite. Similarities in the crystal structure of the five soil parent material clays suggest that they were likely transported from the same source. Despite the differences in percentage of clay minerals, similarities between chemical composition of the coarse and the fine clays is interpreted as an indication of close diagenetic relationships between the predominant smectite and soil mica. High silicate bound iron may have caused a distortion in the crystal lattice and a slightly favorable weathering condition of smectites. However, presence of high exchangeable and soluble magnesium in the soil complex is likely retarding the smectite alteration. Thus, weathering by elemental substitution may have been restricted to the smectite end member only. Key words: Swelling clay soils, iron montmorillonite, chemical composition of smectites, dehydration of smectites

Aluminium influence on iron oxides: XVIII. The effect of Al substitution and crystal size on magnetic hyperfine fields of natural goethites

Clay Minerals ◽  
1996 ◽  
Vol 31 (4) ◽  
pp. 455-464 ◽  
Author(s):  
J. Friedl ◽  
U. Schwertmann
Keyword(s):  
Iron Oxides ◽  
Room Temperature ◽  
Crystal Size ◽  
Tropical Soil ◽  
Iron Ores ◽  
Hyperfine Fields ◽  
Al Substitution ◽  
Subtropical Soils ◽  
Crystallization Conditions ◽  
The Mean

AbstractTwo sets of natural Al-substituted goethites from contrasting surface environments (24 tropical and subtropical soils vs. ten lake iron ores from Finland) were characterized by Mössbauer spectra obtained at room temperature and 4.2 K. A negative correlation between Bhf and Al substitution (R2 = 0.751) was found by combining the data of all the samples, which was slightly improved (R2 = 0.779) by taking the mean coherence length perpendicular to 111 (MCL111) into account. The effect of Al on lowering Bhf was, however, stronger for the tropical soil goethites than for those of the lake ores. This is parallelled by a corresponding difference in the unit-cell decrease per unit Al substitution. These differences are believed to result from the crystallization conditions in the two different environments.

Fluctuations in the Local Fields Due to Al3+ Ions Substitution in the M-Type Barium Hexaferrites, BaFe12-xAlxO12

1998 ◽  
Vol 12 (27n28) ◽  
pp. 2847-2855 ◽  
Author(s):  
S. Thongmee ◽  
T. Osotchan ◽  
P. Winotai ◽  
I. M. Tang
Keyword(s):  
Saturation Magnetization ◽  
Half Width ◽  
Local Fields ◽  
The Other ◽  
Mossbauer Spectrum ◽  
Line Broadening ◽  
Barium Hexaferrites ◽  
Al Substitution ◽  
Linear Decrease ◽  
Aluminum Substitution

The effects of aluminum substitution into the M-type Ba-hexaferrites on the saturation magnetization and Mossbauer spectrum of these ferrites are studied. The saturation magnetization M s of the BaFe 12-x Al x O 12 is seen to decrease linearly with increasing Al substitution. The Mossbauer spectrums for the x = 0.1, 0.2 and 0.6 specimens were all resolved as superpositions of four sub-spectrums (12k, 4 fiv +2 a , 4 fvi and 4e). The half width of the Mossbauer lines of the 4 fiv+2a sextets is seen to broadening as Al ions are substituted into the ferrite. No broadening is seen in the lines of the other sextets. These behaviors (the line broadening and the linear decrease in M s ) are consistent with the Al 3+ ions substituting preferentially into the 2a sites.

The soil clays of Great Britain: II. Scotland

Clay Minerals ◽  
1984 ◽  
Vol 19 (5) ◽  
pp. 709-735 ◽  
Author(s):  
M. J. Wilson ◽  
D. C. Bain ◽  
D. M. L. Duthie
Keyword(s):  
Clay Minerals ◽  
Clay Mineralogy ◽  
Parent Material ◽  
Granitic Gneiss ◽  
Parent Materials ◽  
Red Sandstone ◽  
Rock Types ◽  
Soil Parent Material ◽  
Soil Clays ◽  
Lower Palaeozoic

AbstractThe soils of Scotland are relatively young, being developed mainly on glacial drift deposited some 10 000 years ago. Only a small number of genetic soil types are represented, but this is more than compensated for by the wide variety of parent materials from which the drift ultimately derives. The major parent materials include granite and granitic gneiss, gabbro, basalt/andesite, mica-schist and related metamorphic rock types, Lower Palaeozoic greywackes and shales, Old Red Sandstone sediments, Carboniferous sediments, fluvioglacial sands and gravels, and estuarine silts and clays. The clay mineralogy of the soil associations developed on these parent materials is described and the origin of the clay minerals is interpreted. It is concluded that the influence of inheritance is predominant, but that the effects of pre-glacial weathering and Holocene pedogenesis can also be discerned. Inheritance has contributed a wide variety of clay minerals to the soils, including illite, kaolinite, chlorite, smectite and a number of interstratified minerals, pre-glacial weathering has resulted in the widespread formation of kaolinite and halloysite, irrespective of soil parent material or drainage class, and recent pedogenesis has brought about the transformation of inherited layer silicates by vermiculitization processes, with concomitant interlayer alumination, particularly in surface horizons.

Concentration of iron oxides from soil clays by 5 m NaOH treatment: the complete removal of sodalite and kaolin

Clay Minerals ◽  
1991 ◽  
Vol 26 (4) ◽  
pp. 463-472 ◽  
Author(s):  
Balwant Singh ◽  
R. J. Gilkes
Keyword(s):  
Iron Oxide ◽  
Iron Oxides ◽  
Crystal Size ◽  
Complete Removal ◽  
Complete Dissolution ◽  
Al Substitution ◽  
Soil Clays ◽  
Naoh Treatment ◽  
Very High

AbstractThe Kämpf & Schwertmann (1982) procedure for concentrating iron oxides in soil clays by dissolution of kaolin and gibbsite by boiling for 1 h in 5 m NaOH may not dissolve all kaolin, and also results in the precipitation of sodalite. For the complete dissolution of kaolin in kaolin-rich soil clays a boiling time of 2 h in 5 m NaOH was required. The large amounts of sodalite produced were not removed by the prescribed single wash in 0·5 m HCl. Oxalate soluble Al contents of iron oxide concentrates were sometimes very high and dithionite Fe contents were very low both in concentrates containing sodalite, and in those for which sodalite was not detected by XRD, but where a previously unsuspected amorphous sodalite-like phase may have been present. Complete removal of precipitated sodalite was achieved by two extractions with 0·5 m HCl at 25°C for 20 min. This modified procedure does not alter the Al-substitution and crystal size of goethite, hematite and maghemite as determined by XRD measurements.

Variations in the properties of iron oxides within individual specimens of lateritic duricrust

Soil Research ◽  
1987 ◽  
Vol 25 (3) ◽  
pp. 287 ◽  
Author(s):  
RR Anand ◽  
RJ Gilkes
Keyword(s):  
Iron Oxides ◽  
Crystal Size ◽  
Al Substitution ◽  
History Of

The morphologically distinct materials in Darling Range lateritic duricrust (i.e. loose and cemented pisoliths, concretions, matrix, pisolith coatings and void coatings) exhibit goethite/(goethite + hematite) ratios ranging from 0.15 for individual pisoliths to 1.0 for void coatings. Mole % Al substitution ranged from 20 to 34% in goethite and from 2 to 15% in hematite. Goethite and hematite in pisoliths and concretions were mostly highly Al substituted. Al substitution in goethite was positively related (P < 0.01) to Al substitution in hematite. Al substitution in maghemite was less than 5%. Goethite crystals ranged in size from 130 to 260 A. Hematite crystals ranged from 140 to 520 A, and were systematically smaller in pisoliths. Crystal size of goethite and hematite decreased with increasing Al substitution. Hematite crystals were usually about 50% larger than goethite crystals in the same sample, and crystal sizes of goethite and hematite were positively correlated (P < 0.01). Goethite and hematite occurred as aggregates of subrounded platy crystals. Differences in the properties of goethite and hematite between morphologically distinct materials in single hand specimens are indicative of the complex history of these duricrusts.

scholarly journals Clay formation and podzol development from postglacial moraines in Switzerland

Clay Minerals ◽  
1999 ◽  
Vol 34 (2) ◽  
pp. 319-332 ◽  
Author(s):  
D. Righi ◽  
K. Huber ◽  
C. Keller
Keyword(s):  
Acid Soils ◽  
Soil Development ◽  
Parent Material ◽  
Soil Horizon ◽  
Significant Finding ◽  
X Ray Diffraction ◽  
Soil Parent Material ◽  
Fine Clay ◽  
Clay Formation ◽  
Mixed Layers

AbstractThe fine silt (2–5 μm) and fine clay (<0.1 μm) fractions from four acid soils developed from moraines of increasing age (80, 400, 3,000 and 6,500 years old) in Switzerland, were studied by X-ray diffraction and chemical analyses. The soil parent material is homogeneous at the four sites and the soils can be considered as forming a chronosequence of soil development leading to the formation of Podzols. Mineralogical evolution of silt-sized phyllosilicates and fine clay fractions follows different pathways according to their composition and the soil horizon in which they are located. Dioctahedral and trioctahedral minerals in the soil parent material were both weathered in the Bw and Bs horizons but the trioctahedral phase more strongly and faster than the dioctahedral one. Weathering products are mica-vermiculite mixed-layers, vermiculite and finally gibbsite and Fe oxy-hydroxides. Weathering of the trioctahedral fraction was faster in the eluvial A or E horizons than in the B horizons, being almost complete after 3,000 years of soil development. Appreciable weathering of the dioctahedral fraction occurs only in the eluvial horizons leading to the formation of mica-smectite mixed-layers and smectite. Although smectite has been reported in the E horizon of Podzols in different environments, the significant finding in this work is the presence of this mineral in soils developed from the same parent material. This supports the fact that smectite is the end- product of mica alteration in strongly leached and acidified E horizons of Podzols.

Ca-Mg ratios for evaluating pedogenesis in the piedmont province of the southeastern United States of America

2001 ◽  
Vol 81 (4) ◽  
pp. 415-421 ◽  
Author(s):  
J N Shaw ◽  
L T West ◽  
B F Hajek
Keyword(s):  
Parent Material ◽  
Soil Survey ◽  
Forest Fertilization ◽  
Mafic Rocks ◽  
Parent Materials ◽  
Soil Parent Material ◽  
Southeastern Us ◽  
Exchangeable Ca ◽  
Selective Retention ◽  
National Cooperative

The nature of parent materials strongly influences soil development in the southeastern US Piedmont. In this region, most parent materials (saprolite) form from metamorphic and igneous felsic and mafic rocks. Although most soils in felsic terrains are acid and kaolinitic, soils formed from mafic parent materials range from kaolinitic Ultisols to Alfisols with smectite. Because it is sometimes difficult in soils developed in mixed terrains to determine parent material influence, exchangeable Ca/Mg ratios were used to elucidate soil-parent material relationships. Establishment of Ca/Mg signatures diagnostic of soil-parent material suites could facilitate soil mapping activities and forest fertilization regimes. Characterization data collected as part of the National Cooperative Soil Survey (mainly Georgia and Alabama) were evaluated, and soils were grouped by parent material type. The Ca/Mg ratios did not prove to be diagnostic for separating parent materials; however, significant depth trends existed. In most of the groupings, Ca/Mg ratios decreased with depth in the solum, which was most likely due to selective retention of Ca2+ and the effects of bio-cycling. The ratio either increased below the solum (mafic soils), or continued to decrease (felsic soils). Thus, these ratios are useful for identifying solum depth in some of these soils. The (Ca + K)/Mg ratios were more diagnostic with regard to parent material. These data suggest soils possessing ratios of (Ca + K)/Mg < 2 within the solum (excluding surface horizons) have been significantly influenced by mafic parent materials. Key words: Piedmont, Ca-Mg ratios, Ultisols, Alfisols, pedogenesis

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