The Influence of Ionic Environment on the Nature of Iron Oxides in Soils

Taylor, R. M.; Graley, AM

doi:10.1111/j.1365-2389.1967.tb01512.x

Cited by 31 publications

(12 citation statements)

References 3 publications

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“…The presence of organic matter may also affect the crystallization of iron oxides (Schwertmann, 1966), and the ionic environment, particularly the presence of Ca 2 § and Mg 2+, may direct the crystallization toward hematite (Schellmann, 1959;Taylor and Graley, 1967).…”

Section: Micromorphology Of Particle Surfacesmentioning

confidence: 99%

Deferration Effect on Structural Ferrous-Ferric Iron Ratio and CEC of Vermiculites and Soils

Roth

1969

Clays and clay miner.

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Abstract-Deferration by reduction of free Fe203 with Na,zS20~ in the presence of Na citrate and NaHCO~ caused a change in valence state of I 0 to 35 per cent of the total structural iron in micaceous vermiculites, soils, nontronite, and muscovite. An increase in FC + on deferration was accompanied by an equivalent decrease in Fe 3.. Subsequent treatment with H202 reoxidized the structural Fe z+ previously formed.Sesquioxide coatings on micaceous vermiculites were examined electron microscopically, These coatings were composed predominantly of Fe203 with approximately 10 per cent by weight of AI2Oa and small amounts of SiO2, as determined by chemical analysis of the deferration extracts.The cation exchange capacity (CEC) increased 10-60 per cent as a result of deferration of micaceous vermiculites and soils. Treatment of the deferrated sample with H202 restored the Fe 3+ content to approximately the original value but the CEC was not affected. Consequently, the increase in CEC on deferration was attributed to the removal of the positively charged sesquioxide coating. The reversible change in valence of structural iron without an equivalent change in CEC was attributed to deprotonation-protonation of the structure (OH-~ 02 ) simultaneous with the oxidation-reduction of iron (FC + ~ Pe a+) in the phyllosilicate layer.

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Section: Micromorphology Of Particle Surfacesmentioning

confidence: 99%

Deferration Effect on Structural Ferrous-Ferric Iron Ratio and CEC of Vermiculites and Soils

Roth

1969

Clays and clay miner.

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“…Collepardi et al (1972; demonstrated that at pH 5.3 and temperature of 100°C the presence of salts generally accelerates the transformation of ferrihydrite to haematite and inhibits goethite formation, but under alkaline pH conditions the presence of salts does not affect the rate of formation of either goethite or haematite. The results obtained by Taylor and Graley (1967) suggest that calcium or magnesium may also favour formation of haematite relative to goethite, and Lewis and Schwertmann (1979) indicate a similar effect due to the presence of aluminium. Other work has shown that aluminium may occur as an impurity by isomorphic substitution in both goethite and haematite (Golden et al, 1979), and in such cases it may act to inhibit the growth of ferric oxide crystals (Norrish and Taylor, 1961).…”

Section: Precipitation Of Ferric Oxides and Hydroxidesmentioning

confidence: 92%

Nature, origin and palaeoenvironmental significance of red coastal and desert dune sands

Gardner¹,

Pye²

1981

Progress in Physical Geography: Earth and Environment

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Red and orange iron-stained sands of relatively recent age occur widely in both coastal dunefields and continental deserts in the tropics and subtropics. Red desert dune sands have been described from elsewhere ( Figure 1). Not all tropical and subtropical dunes are red, but in general aeolian red sands are more common in these areas than in temperate and high latitudes.The question of the nature and significance of red sediments in general has concerned geologists for many years, since reddening is often an important process associated with diagenesis, and because ancient red sediments occur widely in the geological record (Van Houten, 1973). The debate concerning red sediments has centred around two main questions; first, the nature of the climatic conditions which best favour reddening, and hence the palaeoclimatic inferences which can be drawn from fossil red beds; and, second, the role of time in the reddening process.Several authors have discussed these issues with reference to recent sediments in particular areas (e.g. Norris, 1969; Folk, 1976;Walker, 1979), but little attention has been given to patterns of reddening at the wider global scale.The purpose of this paper is to review the present state of knowledge regarding the nature, origin and palaeoclimatic significance of red dune sands within the context of late Quaternary environmental change. The paper is therefore concerned with reddening of sands under subaerial conditions rather than at high temperature and pressures. Processes of reddening during diagenesis have recently been reviewed by Walker (1976) and Turner (1980) in relation to the general problem of continental red beds. The discussion stems in part from recent investigations carried out by the authors on red dune sands in southern India and northeast Australia. These investigations will be described in more detail elsewhere. IThe nature of red dune sands .

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“…low temperatures and high rainfall) when the original soil-saprolite was formed. Under similar macroclimates, many studies dealing with red-yellow soil associations at different altitudes (climatic gradients) or distances from the sea (maritime vs continental) have shown that hematite oxides formed at low elevation sites can be absent in the mountains as a result of low temperatures and high rainfall (Alexander et al, 1993;Cornell and Schwertmann, 2003;Palmieri, 1986;Schwertmann et al, 1982;Schwertmann and Latham, 1986;Taylor and Graley, 1967). The formation of the original soilsaprolite sequence in the Mayombe Mountains before erosion processes, currently at a maximum elevation of 900 m above sea level, was likely to occur under unsuitable conditions for hematite formation and might explain the current iron oxide compositions of our soils.…”

Section: Iron Oxidesmentioning

confidence: 97%

Mineralogical and physico-chemical properties of Ferralic Arenosols derived from unconsolidated Plio-Pleistocenic deposits in the coastal plains of Congo

Mareschal

Nzila²,

Turpault

et al. 2011

Geoderma

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The Influence of Ionic Environment on the Nature of Iron Oxides in Soils

Cited by 31 publications

References 3 publications

Deferration Effect on Structural Ferrous-Ferric Iron Ratio and CEC of Vermiculites and Soils

Deferration Effect on Structural Ferrous-Ferric Iron Ratio and CEC of Vermiculites and Soils

Nature, origin and palaeoenvironmental significance of red coastal and desert dune sands

Mineralogical and physico-chemical properties of Ferralic Arenosols derived from unconsolidated Plio-Pleistocenic deposits in the coastal plains of Congo

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