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1.
《Geoderma》1987,39(3):193-207
Mineralogies of a soil catena in the Pampa of Ulla Ulla (4,300–4,600 m) and the soils of the steep slopes of the Cordillera de las Muñecas (“steep area”) were investigated. The latter area includes three altitudinal zones: herbaceous zone (3,900–4,800 m), shrub zone (2,700–3,900 m), and mountain forest zone (up to 2,700/2,800 m). The soils were classified according to Soil Taxonomy as Entisols, Mollisols, and Inceptisols. They were mainly derived from quartzitic schists and slope debris. Each horizon of each profile was representatively sampled for analyses.Muscovites and illites were the dominant minerals in the fine silt and clay fraction, respectively. Besides kaolinite, pyrophyllite and vermiculite, regular illite/vermiculite mixed layers, chlorite, feldspar and quartz were detected in both fractions. In a Typic Cryaquent from the Pampa of Ulla Ulla, smectites had been formed. Pyrophyllite, illite/vermiculite mixed layers and chlorite seemed to be unstable under acid conditions in most of these soils. 相似文献
2.
The presence of so-valled chlorite-like minerals has been reported in many soils of not only acid but also of alkaline reaction (1). The minerals have been designated by, many terms, for example, dioctahedral vermiculite (2), dioctahedral analogue of vermiculite (3), 14A mineral (4), chlorite-like mineral (5), interstratified chlorite-vermiculite (6), intergradient chlorite-expansible 2:1 layer silicate, intergradient chlorite-vermiculite, intergradient chlorite-vermiculite-montmorillonite, intergrade, or interlayered vermiculite (7), and 2: 1-2: 2 intergrade (1). The minerals designated by these terms are evidently of the same category, and some of them are synonymous. Although they are of intermediate properties, between true chlorite and true vermiculite or montomorillonite, they could be regarded as an independent group of minerals in the course of pedochemical weathering. Jackson (1), for instance, has given the minerals the position of “weathering index 9”, placing them between vermiculite and kaolin as equivalent to montmorillonite, or secondary chlorite and kaolin in his weathering sequence. An explanation of the diagenesis of the minerals has been recently attempted by synthesis of the chlorite-like structures from montmorillonite (8), (9) and vermiculite (10) and mineralogical analyses of soil clay fractions (7). 相似文献
3.
D.C. Bain 《Geoderma》1977,17(3):193-208
The dominant mineral in the clay fractions from the basal horizons of a podzol developed on till derived mainly from chlorite-schists in Argyllshire is oxidized, iron-rich chlorite. Towards the profile surface, the chlorite decreases in amount, becoming absent in the A2 horizon in which the dominant mineral is a complex dioctahedral interstratified phase formed from dioctahedral mica and composed of mica and vermiculite. The absence of any trioctahedral mineral in the A2 horizon together with the marked loss of iron and magnesium from the clay fraction from this horizon indicates that the chlorite, a thuringite, has been destroyed, the only detectable product being goethite. In other apparently similar soils chlorite persists throughout the profiles. As the Eredine podzol contains translocated humus in the B2 horizon, it is suggested that during podzolization, organic solutions percolated downwards from the surface, formed complexes with iron and aluminium from the chlorite structure, removing them to the B2 horizon, and thus eventually dissolved out the chlorite from the A2 horizon. 相似文献
4.
Minerals of the pedogenic chlorite group were studied in the clay fractions isolated from the mineral horizons of podzolic
and gleyic peat-podzolic soils. In the AE and E horizons of the podzolic soil, pedogenic chlorites are thought to develop
from vermiculite, whereas in the E horizon of the gleyic peat-podzolic soil, they can be formed from smectite minerals. For
estimating the degree of chloritization (the degree of filling of the interlayer space of 2: 1 minerals with Al hydroxides),
a numerical criterion was is proposed. The difference between the values of this criterion before and after the treatment
of the preparations with NH4F indicated that the degree of chloritization in the pedogenic chlorites decreases in the following sequence: the E horizon
of the podzolic soil > the AE horizon of the podzolic soil > the E horizon of the gleyic peat-podzolic soil. Another numerical
criterion was proposed to estimate the degree of polymerization of Al-hydroxy complexes in pedogenic chlorites. This criterion
was based on the thermal stability of soil chlorites and represented the temperature at which an increase in the intensity
of the 1.0-nm peak after heating the K-saturated preparations exceeds 50% of its initial value. According to this criterion,
the degree of polymerization of the Al-hydroxy interlayers in pedogenic chlorites decreases in the following sequence: the
E horizon of the podzolic soil > the E horizon of the gleyic peat-podzolic soil ≥ the AE horizon of the podzolic soil. The
distinct interrelation between the soil properties and the degrees of chloritization and polymerization of the Al-hydroxy
interlayers attests to the modern origin of the pedogenic chlorites. 相似文献
5.
Yu Zhan Zhang Yangzhu Sheng Hao Zhang Liang Zhou Qing Yan Xiong 《Journal of Soils and Sediments》2020,20(3):1558-1570
Purpose
The aims of this study were to investigate the composition of clay minerals in soils derived from different parent materials and to elucidate how parent materials and pedogenic environment affect the distribution of clay minerals and reveal the implications for pedogenetics and taxonomy in Stagnic Anthrosols.
Materials and methodsClay mineralogy and physicochemical properties of the Hydragric horizon of Stagnic Anthrosols derived from granite (GR), plate shale (PS), quaternary red clays (QRC), limestone (LS), purple sandy shale (PSS) and fluvial-lacustrine deposit (FLD) located in Hunan Province of China were analysed to explore the relationships between the conditions influencing the formation of the soil and the composition of clay minerals.
Results and discussionResults indicated that the composition of clay minerals is closely related to both parent material and type of Stagnic Anthrosols: the soils derived from GR, PS and QRC, which are mostly classified as Fe-accumulic-Stagnic Anthrosols, are dominantly 1:1 type kaolinite and vermiculite and illite/vermiculite mixed layer minerals of widespread distribution. However, soils derived from LS, PSS and FLD were mainly classified as Hapli-Stagnic Anthrosols and are mainly composed of 2:1 type illite/smectite mixed layer minerals, where chlorite is commonly found. Illite is widely distributed and its content varies the least among different parent materials. An extremely significant relationship between pH and kaolinite, chlorite and mixed layer minerals was noted, and the two kinds of mixed layer minerals showed highly significant negative correlation.
ConclusionsThis study revealed that the types and quantities of clay minerals in the soil are closely related to the types of parent material. This reflected better direction and degree of development in Stagnic Anthrosols, which is related to the physicochemical properties of parent material and can be used as one of the bases for the classification of soil groups and subgroups within the soil family for Stagnic Anthrosols in Chinese Soil Taxonomy.
相似文献6.
The amounts of monomeric silica released on trimethylsilylation of a range of Soil Groups of the Darleith Soil Association, developed on glacial till derived from Carboniferous age lavas of basic and intermediate composition, is significantly higher than the amounts released from corresponding Soil Groups of the Lauder Soil Association, developed on glacial till derived from Devonian age conglomerates and sandstone. Monoremic silica release values for the leached soils within an association are, in general, higher than those of the gley soils. For all soil profiles the eluvial horizon released the smallest amount of monomeric silica with the maximum amount being released, in most instances, from the illuvial horizon. Ferromagnesian minerals and crystalline clay minerals, in particular vermiculite and chlorite in the Darleith Association soils, release monomeric silica under acid conditions. For both the Darleith and Lauder Association soils the principal source of monosilicic acid is thought to be aluminosilica gel of low Si:A1 ratio. 相似文献
7.
The formation of partially interlayered vermiculite (PIV) was studied in six Dystrochrepts derived from Tertiary sediments. Mineralogy of silt and clay fractions of gravel and fine earth separated from surface and subsurface samples were determined by X-ray diffraction. PIV, mica, vermiculite and regularly interstratified 1:1 PIV/chlorite (PIV/Ch(l:l)) were the dominant clay minerals. The contents of these minerals were compared between the specific particle-size fractions of gravel and fine earth for each sample and the difference was interpreted in terms of mineral transformation associated with soil formation. PIV was formed from mica and PIV/Ch(l:l) in soils with a pH(KCl) of 3.5 to 4.0 and little organic matter. Vermiculite was formed from mica in surface soils with a low pH (pH(KCl) 3.5) and abundant organic matter. PIV would form directly from mica without an intermediary phase of vermiculite and form from PIV/Ch(l:l) by partial dissolution of interlayers in chlorite layers. 相似文献
8.
Characteristics of Clay Minerals in Podzols and Podzolic Soils 总被引：1，自引：0，他引：1
Yasuo Kitagawa 《Soil Science and Plant Nutrition》2005,51(2):151-158
The clay minerals in Podzols and podzolic soils developed under coniferous forests in the Subarctic and Cool-temperate zones are characterized by the predominance of smectite and/or mica-smectite interstratified minerals in the eluvial horizons and chlorite-vermiculite intergrade in the illuvial horizons. A large amount of vermiculite is present in the eluvial horizons of some podzolic soils in the Cool-temperate zone. The illuvial horizons of these soils also contain free iron oxides such as goethite. Imogolite and allophane are present in the illuvial horizons of several soils derived from volcanic ashes. It is suggested that the critical bioclimate for the release of interlayered aluminum from the 2:1-type minerals lies between the Cool- and Warm-temperate zone. In the eluvial horizons of Podzols and podzolic soils, mica minerals and chlorite, as primary minerals, have been transformed to smectite through the pedogenic process. Based on previous studies on the structure and degradation of the dioctahedral mica minerals, it is considered that smectite is transformed from 1M-type mica minerals directly, and from 2M-type mica minerals via mica-smectite interstratifled minerals. The formation of a smectite lattice in the eluvial horizon should be a clay-mineralogical indicator of podzolization. 相似文献
9.
The mineralogies of ‘Tirs’ (Typic Pelloxererts), and ‘Debs’ (Typic Haploxerolls and Typic Xerochrepts) soils of the Gharb plain in north-western Morocco are investigated, with special attention given to the determination of the nature of the smectitic phase using the lithium test (Li test) and the alkylammonium method. The sand and silt mineralogy of Tirs soils is dominated by quartz with small amounts of feldspars and kaolinite. The sand and silt fractions of Dehs soils also contain significant amounts of mica, chlorite, and interstratified phyllosilicates. The clay minerals of Tirs soils are predominantly a high-charge smectite. The estimated interlayer charge for this phase is 0.61 mol(c)/O10(OH)2 and the fraction of tetrahedral charge varies from 38 to 44%. Although the percentage tetrahedral charge is less than 50%, the smectitic phase behaves as beidellite with the Li test. Dehs clays are more heterogeneous, consisting of smectite, vermiculite, illite, kaolinite, chlorite, and interstratified illite/smectite and illite/vermiculite. The Li test and the alkylammonium method demonstrate that a high-charge smectite or vermiculite is interstratified with illite. A low-charge montmorillonite is also present both in Tirs and in Dehs soils. The high-charge beidellitic phase is believed to be a transformation product of mica, whilst the low charge montmorillonite is thought to be inherited from the parent material. 相似文献
10.
The biotite changes in the 1–5 μm fraction after its occurrence in the F, H, AE, and E horizons of a pale-podzolic soil for
five years under conditions of a model field experiment were assessed by X-ray diffraction analysis. It was found that the
main changes of the biotite in all the horizons included the degradational transformation of its crystal lattice to interstratified
mica-vermiculite structures and vermiculite. The intensity of this process gradually decreased from the F horizon down the
profile in parallel with the decrease in the amount of roots and the abundance and activity of microbiota. Chloritized structures
were present among the products of the biotite weathering in the H, AE, and E horizons; the degree of chloritization gradually
increased from the H horizon to the E horizon. The main identified products of the biotite weathering in the AE and E horizons
formed during the 5 years of the model experiment were identified in the clay and fine-silt fractions from these horizons
of the native pale-podzolic soils. Therefore, the vermiculite, soil chlorite, and mixed-layer illite-vermiculite minerals
in the soils studied could be considered as products of the recent soil functioning. The obtained results and literature data
showed that the weathering of biotite resulted in the formation of K- and Al-buffer systems. 相似文献
11.
A study was made of the weathering of trioctahedral, iron-rich chlorite and dioctahedral mica in a Spodosol (Haplorthod) developed on till derived from chlorite-mica schist.Chlorite in the clay of the B and C horizons has weathered to small amounts of regularly interstratified chlorite-vermiculite, vermiculite and goethite. Chlorite vermiculitization is associated with a loss of iron and aluminum and appears to result in a change toward dioctahedral structure. Chlorite and its trioctahedral vermiculitic products are absent from the clay, silt and sand of the Ae horizon which is probably due to decomposition by organic acids.Mica in this soil weathers and expands to dioctahedral, regularly interstratified mica-ermiculite and discrete vermiculite products that increase in abundance towards the profile surface and are dominant in the clay of the Ae horizon. Amounts of mica-derived vermiculite products decrease with increase in particle size and are practically absent in the sand of the Ae horizon.Comparing mineral weathering in this Spodosol with that in other soils, developed on similar greenschist material but in warmer climates or during longer times, shows that amounts of chlorite-derived vermiculite in the subsoils of the latter soils are much larger, decrease towards the profile surface, and increase with larger particle size. The evidence indicates that weathering of chlorite to vermiculite and accumulation of the vermiculite products are optimal in non-eluvial, moderate weathering conditions. 相似文献
12.
M. J. WILSON 《European Journal of Soil Science》1973,24(1):26-41
The clay mineralogy of thirty-two profiles located mainly in the Vale of Strathmore and developed on glacial till derived from Lower Red Sandstone sediments and lavas has been investigated by X-ray diffraction. The soils were selected so that the parent material was related predominantly to one of the rock types common in the Lower Old Red Sandstone succession—namely, marl, sandstone, lava, or conglomerate. Comparison of the < 1.4μm fractions separated from fresh rock samples with those separated from the C horizons of the soils clearly established the dominant influence of parent rock on the soil-clay mineralogy. The clay minerals inherited by the soil often include unusual trioctahedral expansible minerals such as saponite, interstratified vermiculite-chlorite, and smectite-vermiculite, as well as more common types like mica, montmorillonite, and chlorite. Kaolinite is also found but it is not certain that it is only of inherited origin. Weathering of the clays during soil formation brings about complete degradation of the expansible trioctahedral minerals, a process usually well advanced in the B or even at the top of the C horizon, and vermiculitization of mica. The latter process occurs mainly in the A horizon, with concomitant precipitation of interlayer aquohydroxy-aluminium ions thereby forming a vermiculite-chlorite intergrade. Chlorite and kaolinite appear to be little affected by weathering. The weathering transformations are most pronounced in freely drained acid soils (pH < s) and are at a minimum in poorly drained soils and where the pH remains above 6. The susceptibility to weathering of the trioctahedral expansible minerals results in relatively high values for exchangeable magnesium at the base of the profile. 相似文献
13.
贡嘎山海螺沟冰川退缩区土壤序列矿物组成变化 总被引：1，自引：1，他引：1
阐明土壤中矿物随时间变化的机制是理解矿物风化和土壤发育的基础。利用X射线衍射法对贡嘎山海螺沟冰川退缩区土壤矿物组成随成土作用时间变化进行了定量分析。结果表明,冰川退缩区成土母质的矿物组成同质性较高,以硅酸盐矿物为主(约90%),包括:斜长石(28.5%)、石英(24.5%)、黑云母、钾长石、普通辉石、角闪石、绿泥石、蛭石;并有少量碳酸盐矿物,如方解石(8%)、白云石(2.3%);以及磷酸盐矿物磷灰石(2.1%)。退缩区土壤的矿物组成总体呈新发育土壤特征,随着成土年龄的增加,方解石逐渐被风化成为草酸钙石,角闪石、黑云母、磷灰石和绿泥石含量逐渐降低,长英质矿物的相对含量有所增加。成土作用中矿物组成的变化受植被原生演替和土壤p H的影响,快速发育的植被导致土壤p H迅速降低,风化程度增强。 相似文献
14.
A procedure for quantifying minerals in particle size fractions of fine earth (< 2 mm) is presented. Mineral fractions of the acid forest soils are characterised by various transition products. Transitional minerals between illite and vermiculite or smectite, polyhydroxy-Al polymers interlayered in smectite and vermiculite, as well as poorly crystalline compounds are present. Normative calculations with standard minerals, generally applied to rocks, cannot be used to quantify precisely minerals of these soil samples. Conventional qualitative and quantitative chemical analyses are therefore completed by microanalyses of well-identifiable minerals. The calculation procedure is based mainly on a system of simultaneous linear equations. These are set up from the chemical contents of a particle size fraction on the one hand and from the corresponding element contents of single minerals on the other hand. The contribution of single minerals to overall parameters can be calculated by programmed algorithms. The methodology was adjusted to different particle size fractions. 相似文献
15.
We have selected seven profiles located in a diapiric formation in the North of Spain. The profiles have been analyzed for the mineralogy and the chemical composition of original materials, soils developed above them and clay fractions. Three soils formed on basic rock of volcanic origin (ophite) and rich in alterable minerals, three others formed on clay marl and one soil formed on gypsiferous marl. Plagioclases, pyroxenes, vermiculites, and biotites are the main minerals found in the soil samples and ophitic rocks. Biotite, smectite, chlorite and interstratified chlorite–vermiculite make up the predominant mineralogical association in the clay fraction of the soils. Calcite, biotite and on top of all chlorite are the main minerals in the marls and the soils developed on them, with gypsum predominant in the gypsiferous marl. The mineralogy of its clay fraction is comprised mainly of chlorite and biotite. The variations in content of Al2O3, TiO2 and Na2O in the ophites are considered to be associated with the differences in the evolution of the pyroxenes. The variability of the chemical composition of the Keuper sediments and the soils is attributed more to the chaotic disposition of the Triassic materials in the formation of the diapir than to intense chemical weathering. The low concentrations of silica, iron, and aluminum extractable with ammonium oxalate indicate the low proportion of non-crystalline products. Fundamentally, it is the semiarid conditions in the study zone, together with the processes of extrusion and hydrothermal activity affecting the formation of the diapir, that are responsible for the genesis of the minerals. 相似文献
16.
Previous investigations had shown that about 80 years of Norway spruce monoculture on an ochreous brown earth of the Belgian Ardennes were sufficient to accentuate the weak podzolization process already present in the climax beechwood soil and to increase the weathering of several minerals, e.g. 2:2 clay minerals. In order to evaluate more accurately mineral weathering and spruce-induced losses of nutrient elements, an isoquartz assessment method has been applied to a pair of soil profiles, one developed under beech, the other under spruce.
Results show a clear decrease of several weatherable minerals in the soil of the spruce stand which was more marked than in the beechwood, especially for chloritic minerals: losses reach about 30% of the initial chlorite content in the cambic horizon and regularly increase up to 70% in the humic layer. There were severe spruce-induced losses of Mg and Na: 27% of the initial Mg reserve was removed from the whole soil and the losses reached 60% in the upper 20 cm.
It is concluded that 86 years of Norway spruce monoculture have appreciably increased weathering processes and removal of elements. 相似文献
Results show a clear decrease of several weatherable minerals in the soil of the spruce stand which was more marked than in the beechwood, especially for chloritic minerals: losses reach about 30% of the initial chlorite content in the cambic horizon and regularly increase up to 70% in the humic layer. There were severe spruce-induced losses of Mg and Na: 27% of the initial Mg reserve was removed from the whole soil and the losses reached 60% in the upper 20 cm.
It is concluded that 86 years of Norway spruce monoculture have appreciably increased weathering processes and removal of elements. 相似文献
17.
Mineralogical composition of silt and clay fractions (<1.1–5 and 5–10 µm) in heavy loamy agrogrey soils (Luvic Retic Phaeozems) considerably changes both in the vertical (along the soil profile) and horizontal (along soil microcatenas) directions. The eluvial–illuvial distribution pattern of the clay fraction in the podzolized agrogrey soils with the second humus horizon is replaced by the homogeneous distribution in the agrogrey soils with residual carbonates. The distribution of silt fractions in the soil profiles is relatively homogeneous. The clay (<1 µm) fraction of the parent material is represented by the poorly ordered micasmectite interstratifications minerals, the proportion between which changes in the soil profiles in dependence on the particular pedogenetic processes. Hydromicas represent the second important component of the clay fraction. They consist of di- and trioctahedral varieties, the proportion between which changes in the soil profiles. Kaolinite and iron–magnesium chlorite are present in smaller amounts. The second humus horizon is characterized by the lowest content of mica-smectite interstratifications minerals with the high content of smectitic layers and by the lowest content of the clay fraction. Silt fractions are composed of quartz, micas, potassium feldspars, and plagioclases. 相似文献
18.
D. J. CHITTLEBOROUGH 《European Journal of Soil Science》1989,40(2):235-250
A Xeralf on feldspathic sandstone was sampled from a hillslope in the Mount Lofty Ranges in order to study its genesis and, in particular, the origin of the strong texture contrast. Micromorphological study demonstrated that the clay present in void argillans and papules in the B2 horizon accounted for only a small amount of the clay present. Elemental analysis of the whole soil (< 2 mm) and sand, silt and clay fractions showed that there had been considerable weathering of both quartz and microcline, which were the dominant minerals present. Kaolinite is the dominant clay mineral weathering product. Illite appears to be forming from vermiculite in the A horizon. Using zircon as an internal standard, it was shown that elemental losses of SiO2 and reductions in weight and volume were similar in A and B horizons. Losses of aluminium and potassium were greatest in the A horizon, least in the B3. There has been an absolute increase in the amount of iron. A possible source is iron from heavy mineral bands upslope. It was concluded from the similarity of the quartz particle-size distributions of the A2, B2 and B3 horizons that the intensity of weathering of quartz was the same in A and B horizons. In the case of feldspar (mostly microcline), there is a greater proportion of feldspar in the fine sand and silt fractions of the A2 horizon than in the B horizon. Weathering of feldspar is greatest in the A horizon. The texture profile is principally a function of greater lateral loss of clay from the A horizons compared to the B horizons. 相似文献
19.
T. A. Sokolova I. I. Tolpeshta I. V. Topunova 《Moscow University Soil Science Bulletin》2010,65(2):61-68
Changes in biotite (fraction 1–5 μm) after exposure in the T2, H, Eih, and E horizons of peatypodzolic gleyic soil under conditions
of a model field experiment were studied by X-ray diffraction. It was found that the main transformations of the biotite in
all horizons included the degradation of its crystal lattice into regularly interstratified biotite-vermiculite and randomly
interstratified biotite-smectite structures and vermiculite. The transformation intensity decreased down the profile simultaneously
with a reduction in the content of organic matter, roots, and microbiota population and activity. Chloritized structures were
also present among the biotite weathering products in the E horizon. The main identified products of biotite weathering formed
in horizons Eih and E over a five-year period of the model experiment were detected in the clay and fine silt fractions of
these horizons and in native peaty-podzolic gleyic soils. This suggests that vermiculite and soil chlorite in the soils studied
are products of soil functioning. It follows from the results, with consideration for literature data, that the weathering
of biotite results in the formation of a potassium-buffering system. 相似文献
20.
《CATENA》2001,43(3):267-276
Four representative profiles of poorly developed soils on consolidated material were studied in the Sierra de Carrascoy (SE Spain). The soils, with A-A/R or A-C/R type profiles, have medium–low contents of organic carbon and nitrogen, and calcium carbonate occurs in only one of the profiles. The pH in aqueous suspension is slightly alkaline. The cation exchange capacity is medium–low, but varies slightly between profiles, and the electrical conductivity of the saturation extract is low. There are wide textural differences. The clay fractions contain illite, kaolinite, vermiculite, smectites, chlorite, quartz and feldspars. The heavy fraction of the fine sand contains mainly opaque minerals and alterites, with some resistant minerals of metamorphic origin. The profiles are classified by F.A.O-I.S.R.I.C.-I.S.S.S. [World Reference Base for Soil Resources. World Soil Resources Reports 84. F.A.O., Rome, 1998] as Calcaric, Eutric and Hyperskeletic Leptosols. According to Soil Survey Staff [Soil Taxonomy. A basic system of soil classification for making and interpreting soil surveys, 2nd edn., United States Department of Agriculture. Natural Resources Conservation Service. US Government Printing Office, Washington, DC, 1999], they are all Lithic and Typic Xerorthents and Lithic Xeric and Xeric Torriorthents. The principal present-day pedogenetic processes in these soils are humification and clay formation. However, profile 1 has evolved from a fersiallitic soil with clay accumulation, although these features have almost disappeared because of erosion and modern humification, pedoturbation and recalcification. Its relict features consist of the remains of a paleoargic horizon inherited from earlier climatic conditions, which was later truncated and is now preserved only in more stable physiographic positions. 相似文献