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1.
F. L. WANG  P. M. HUANG 《土壤圈》1997,7(4):289-296
Limited information is available concerning the mineralogy of paddy soils in the southeastern China. Using chemical methods in conjunction with X-ray diffractometry, we studied the mineral composition of three paddy soils: Jinghua (paddy soil on Quaternary red clay), Fuyang (Hapl-percogenic loamy paddy soil), and Shaoxing (gleyic clayey paddy soil). All the soils contained quartz, mica, vermiculite, chlorite and kaolinite, and the distribution of these minerals varied with soil particle size fractions. The clay fraction of the Fuyang and Shaoxing soils also contained smectite. Although X-ray data did not show the presence of smectite in the Jinghua soil, this mineral was identified by the chemical method, suggesting a transitional property of the mineral in the soil. Hydroxy-Al interlayered minerals were also present in the clay fraction. The amount of smectite in the soils was 31.6 (Shaoxing), 16.5 (Fuyang), and 21.4 (Jinghua) g kg-1; for vermiculite it was 33.3 (Shaoxing), 16.5 (Fuyang), and 8.5 (Jinghua) g kg-1. Smectite was only found in the clay fraction. In contrast, amounts of vermiculite in soil particle size fractions were 3.0~11.4 (sand), 2.1~6.0 (coarse silt), 4.6~18.9 (medium silt), 0.9~40.0 (fine silt), and 17.0~108 (clay) g kg-1. The amount of noncrystalline aluminosilicates in the soils in g kg-1 decreased in the order: Shaoxing (2.4) > Jinghua (1.9) > Fuyang (1.7). This study has provided useful mineralogical information that is fundamental in future development of management strategies of the soils.  相似文献   

2.
Mineral Composition and Weathering of Soils Derived from Xiashu Loess   总被引:1,自引:0,他引:1  
Mineralogical, physical and chemical analyses of the soils derived from Xiashu loess were carried out. The primary minerals of these soils were found to be mainly composed of light minerals, such as quartz, feldspar and mica, with traces of heavy minerals. Clay minerals, more complicate in composition, were dominated by hydromica, accompanied by smectite, vermiculite, chlorite, kaolinite, 2:1/1:1 randomly interstratified minerals and small amounts of quartz, goethite, lepidocrocite and hematite, Clay minerals were characterized by low crystallinity and fine particle size. In light of the quartz/feldspars ratio of the 0.01-0.05mm silt fraction, and the clay mineral composition, the freeness of iron oxide, and the silica/sesquioxide and silica/alumina ratios in < 0.002mm clay fraction, it is concluded that the weathering intensity of these soils was lower than those of red soil and yellow earth, but higher than that of brown earth, and that the soil allitization, depotassication and hydroxylation of cl  相似文献   

3.
《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   

4.
The mineralogical composition of agrogray, dark gray, and agro-dark gray soils (Luvic Greyzemic Retic Phaeozems); agro-dark gray residual-calcareous soils (Calcaric Cambic Phaeozems); clay-illuvial agrochernozems (Luvic Chernic Phaeozems); and agrochernozems with migrational–mycelial carbonates (Haplic Chernozems) developed in the forest-steppe of Central Siberia within the Irkutsk Depression has been studied. The clay (<1 μm) fraction separated from these soils consists of mixed-layer minerals with alternating layers of hydromica, smectite, vermiculite, and chlorite; the proportions between them change within the soil profiles. The clay fraction also contains hydromicas, kaolinite, chlorite, and some admixture of the fine-dispersed quartz. Each type of the soils is characterized by its own distribution pattern of clay material with specific alternation of layers in the mixed-layer formations. Mixed-layer minerals of the chlorite–vermiculite type predominate in the upper horizons of texture-differentiated soils. Down the soil profile, the content of mixed-layer mica–smectitic minerals increases. In the clay fraction of arable dark gray-humus soils with residual carbonates, the distribution of the clay fraction and major mineral phases in the soil profile is relatively even. An increased content of well-crystallized kaolinite is typical of these soils. The parent material of agrochernozems has a layered character: the upper horizons are generally depleted of clay, and the middle-profile and lower horizons are characterized by the considerable kaolinite content. In general, the clay material of soils of the Tulun–Irkutsk forest-steppe differs considerably from the clay material of foreststeppe soils developed from loesslike and mantle loams in the European part of Russia. In particular, this difference is seen in the proportions between major mineral phases and between biotitic and muscovitic components, as well as in the degree of crystallinity and behavior of kaolinite and chlorite.  相似文献   

5.
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   

6.
Per Nørnberg 《Geoderma》1980,24(1):25-43
This paper deals with possible mineralogical changes from one particle size fraction to another and from one horizon to another in a Typic Haplorthod. X-ray diffraction and chemical analysis were the main methods used. The investigation indicates that a large part of the fine material in the soil is developed during weathering in situ. Less resistant minerals seem to be protected by being parts of rock fragments in coarser fractions, but once freed from that protection they quickly undergo fragmentation into finer particles. Most of the sand and silt fractions are quartz. The K-feldspar content ranges between about 10 and 20%, the Na-feldspar content from about 15 to 30% and the Ca-feldspar content is very small. The clay minerals are mostly kaolinite and mica and in the A2 horizon, expandable 2:1 minerals containing both smectite and vermiculite layers. The B horizon contains 14 A minerals that resemble interstratified vermiculite—chlorite. In the C horizon both vermiculite—chlorite and clorite occur.  相似文献   

7.
Properties and mineralogy of fine fractions separated from agrochernozems forming a three-component noncontrasting soil combination in the Kamennaya Steppe have been characterized. The soil cover consists of zooturbated (Haplic Chernozems (Clayic, Aric, Pachic, Calcaric)), migrational-mycelial (Haplic Chernozems (Clayic, Aric, Pachic)), and clay-illuvial (Luvic Chernozems (Clayic, Aric, Pachic)) agrochernozems. All the soils are deeply quasi-gleyed because of periodical groundwater rise. The mineralogy of the fraction <1μm includes irregular mica–smectite interstratifications, di- and trioctahedral hydromicas, imperfect kaolinite, and magnesium–iron chlorite. The profile distribution of these minerals slightly varies depending on the subtype of spot-forming soils. A uniform distribution of clay minerals is observed in zooturbated agrochernozem; a poorly manifested eluvial–illuvial distribution of the smectite phase is observed in the clay-illuvial agrochernozem. The fractions of fine (1–5 μm) and medium (5–10 μm) silt consist of quartz, micas, potassium feldspars, plagioclases, kaolinite, and chlorite. There is no dominant mineral, because the share of each mineral is lower than 35–45%. The silt fractions differ in the quartz-to-mica ratio. The medium silt fraction contains more quartz, and the fine silt fraction contains more micas.  相似文献   

8.
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   

9.
辽宁省西部是低山丘陵区,年平均温度7.1℃,年平均降雨量400—500毫米,降雨集中在夏季,具有明显的大陆性气候特征,干燥度小于1,属半干旱类型.植被为油松柞木和草原灌木丛林.土壤属棕色森林土向栗钙土过渡的褐土地带.母质主要为花岗片麻岩风化物.山麓缓坡和河谷两岸为黄土丘陵.在黄土沉积物覆盖层下,常见红色风化壳露头,即红色粘土层.此外,并有松软易风化岩层,如砂岩、页岩和变质岩等.本区近百年来,由于自然植被受到严重破坏,大量水土流失,土壤侵蚀严重,土壤有机质含量低,成为辽宁省的低产区.因此,鉴定本区不同母质的土壤矿物胶体组成及其特征,不仅可以研究这一特定自然条件下土壤矿物的转化和形成,并且有助于了解土壤特性和肥力特征.  相似文献   

10.
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   

11.
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   

12.
对太湖平原地区高产的黄泥土型水稻土的全土(<1毫米)及7个粒级(1—0.25,0.25—0.05,0.05—0.01,0.01—0.005,0.005—0.002,0.002—0.001和<0.001毫米)共8个土样,进行测定。结果表明:黄泥土粘粒部分(<0.002毫米)的粘土矿物,主要由水云母、高岭和蒙脱组成。粗粘粒级(0.002—0.001毫米)和细粘粒级(<0.001毫米)中粘土矿物的分配有明显差异;砂粒级(1—0.05毫米)中除了主要的石英外,还含有少量“铁锰砂”,所以该粒级中的SiO2含量较粉粒级(0.05—0.002毫米)的低,而Fe2O3的含量则相反,容积磁化率也较高;可塑性和膨胀性都是在<0.002毫米时才始现。上述特点与作者过去所研究的白土型水稻土类似。但是,与国内外报道的几种旱地土壤的资料有所不同。  相似文献   

13.
As a consequence of global warming, additional areas will become ice-free and subject to weathering and soil formation. The most evident soil changes in the Alps will occur in proglacial areas where young soils will continuously develop due to glacier retreat. Little is known about the initial stages of weathering and soil formation, i.e. during the first decades of soil genesis. In this study, we investigated clay minerals formation during a time span 0-150 years in the proglacial area of Morteratsch (Swiss Alps). The soils developed on granitic till and were Lithic Leptosols.Mineralogical measurements of the clay (< 2 μm) and fine silt fraction (2-32 μm) were carried out using XRD (X-ray Diffraction) and DRIFT (Diffuse Reflectance Infrared Fourier Transform). Fast formation and transformation mechanisms were measured in the clay fraction. The decreasing proportion of trioctahedral phases with time confirmed active chemical weathering. Since the start of soil formation, smectite was actively formed. Some smectite (low charge) and vermiculite (high charge) was however already present in the parent material. Main source of smectite formation was biotite, hornblende and probably plagioclase. Furthermore, irregularly and regularly interstratified clay minerals (mica-HIV or mica-vermiculite) were formed immediately after the start of moraine exposure to weathering. In addition, hydroxy-interlayered smectite (HIS) as a transitory weathering product from mica to smectite was detected. Furthermore, since the start of soil evolution, kaolinite was progressively formed. In the silt fraction, only little changes could be detected; i.e. some formation of an interstratified mica-HIV or mica-vermiculite phase.The detected clay mineral formation and transformation mechanisms within this short time span confirmed the high reactivity of freshly exposed sediments, even in a cryic environment.  相似文献   

14.
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   

15.
许冀泉  杨德涌 《土壤学报》1964,12(3):275-285
西藏高原突起于我国西南,绝大部分地面的海拔高度在4000米以上,为世界上最高的大高原。它大致在第三纪开始形成,后来曾受第四纪冰川的深刻作用,高山顶部至今仍是冰川的活动场所[1,2]。高原为昆仑山、唐古拉山、喜马拉雅山和横断山等大山脉所盘踞。  相似文献   

16.

Purpose

Inadequate soil use and management practices promote commonly negative impacts on the soil constituents and their properties, with consequences to ecosystems. As the soil mineralogy can be permanently altered due to soil use, this approach can be used as a tool to monitor the anthropogenic pressure. The objective of the present study was to assess the mineralogical alterations of a Brazilian regosol used for grape production for 40?years in comparison with a soil under natural vegetation (forest), aiming to discuss anthropogenic pressure on soils.

Material and methods

Soil samples were collected at depths of 0?C0.20 and 0.20?C0.40?m from vineyard production and natural vegetation sites. Physical and chemical parameters were analysed by classic approaches. Mineralogical analyses were carried out on <2?mm, silt and clay fractions. Clay minerals were estimated by the relative percentage of peak surface area of the X-ray patterns.

Results and discussion

Grape production reduced the organic matter content by 28?% and the clay content by 23?% resulting in a decreasing cation exchange capacity. A similar clay fraction was observed in both soils, containing kaolinite, illite/mica and vermiculite with hydroxy-Al polymers interlayered. Neither gibbsite nor chlorite was found. However, in the soil under native vegetation, the proportion of illite (79?%) was higher than vermiculite (21?%). Whereas, in the soil used for grape production during 40?years, the formation of vermiculite was promoted.

Conclusions

Grape production alters the proportions of soil constituents of the regosol, reducing clay fraction and organic matter contents, as well as promoting changes in the soil clay minerals with the formation of vermiculite to the detriment of illite, which suggests weathering acceleration and susceptibility to anthropogenic pressure.

Recommendations and perspectives

Ecosystems in tropical and subtropical climates can be more easily and permanently altered due to anthropogenic pressure, mainly as a consequence of a great magnitude of phenomena such as temperature amplitude and rainfall that occurs in these regions. This is more worrying when soils are located on steep grades with a high anthropogenic pressure, like regosols in Southern Brazil. Thus, this study suggests that changes in soil mineralogy can be used as an important tool to assess anthropogenic pressure in ecosystems and that soil quality maintenance should be a priority in sensible landscapes to maintain the ecosystem quality.  相似文献   

17.
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 methods

Clay 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 discussion

Results 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.

Conclusions

This 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   

18.
本文研究结果表明:(1)神农架垂直带土壤矿物的风化脱硅作用较弱,粘土矿物以2:1型矿物为主,1:1型高岭含量很少。(2)随海拔升高,矿物的淋溶脱钾和层间羟基铝化作用增强,低海拔土壤的2:1型矿物以水云母为主,高海拔土壤以1.4nm矿物为主,其中1.4nm过渡矿物相对增多。(3)土壤的络合态铁、铝和非晶形铁,铝含量随海拔升高明显增大。(4)土壤的可变电荷量,阴离子交换量,交换性酸和铝饱和度等均随海拔  相似文献   

19.
邓时琴  徐梦熊 《土壤学报》1990,27(4):368-376
赣中丘陵第四纪红色粘土上发育的旱地红壤中粘土矿物的细粘粒(<0.001毫米)部分以高岭石和蛭石为主,并有一定量的水云母和夹层矿物。各级颗粒的化学组成中,随颗粒由粗到细,SiO2的含量大体上也由高到低;Fe2O3的含量则是砂粒级稍稍超过粉粒级,后一情况与作者过去对太湖地区两种水稻土(白土和黄泥土)研究的结果相似。供试红壤粒径<0.005毫米的颗粒才显示抗压强度,而上述水稻土从<0.05毫米的颗粒就开始有抗压强度。同前所试水稻土一样,在供试红壤中,粒径<0.002毫米的颗粒开始表现出可塑性及膨胀性。  相似文献   

20.
For the past ten years much work has been carried out on clay minerals of volcanic ash soils. Most investigators have reported that allophane is dominant among clay minerals of volcanic ash soils and crystallizes to halloysite or meta-halloysite with the advance of weathering (1–8). On the other hand, UCHIYAMA, MASUI and ONIKURA (1960) found that montmorillonite predominates in the clay fraction of volcanic ash soil in Kawatabi (9). Furthermore, MASUI, SHOJI and UCHIYAMA (1966) showed that the major crystalline clay minerals of volcanic ash soils in the Tohoku district are montmorillonite, vermiculite, intergradient montmorillonite-vermiculite and chlorite (10). They also showed that these minerals increase with the advance of weathering and that kaolin minerals are minor constituents.  相似文献   

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