Crystalline clay minerals of the soils derived from recent volcanic ashes in Hokkaido,Japan

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.     

Characteristics of Clay Minerals in Podzols and Podzolic Soils

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.     

Weathering of chlorite in a soil derived from a chloritoschist under humid tropical conditions

Eight samples from a soil derived from greenschist were chosen to represent the weathering transformation of chlorite and were subjected to chemical and mineralogical analyses by X-ray, D.T.A., selective and acid dissolution techniques. Regularly interstratified chlorite-vermiculite is the major weathering product in the sand and silt fractions, whereas nontronite predominates in the clay fraction. Kaolinite and a “chlorite-like” mineral progressively appear in the clay fraction as the soil surface is approached. The results show that the genetic link suspected between the clay chloritic component and the kaolinite does not withstand a detailed examination. The clay chloritic mineral is a disordered remnant of the regularly interstratified chlorite-vermiculite and it appears in the clay fraction of the solum concommitantly with the argillitization of the silt fraction. Kaolinite occurs in close association with nontronite and would perhaps form with this mineral a true mixed-layer phase. The unequal distribution of aluminium, iron and magnesium amongst the available sites in the parent chlorite appears to be a factor that strengthens the divergent behaviour of these elements during the weathering.     

Weathering of chlorite and mica in a new Brunswick Podzol developed on till derived from chlorite-mica schist

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.     

Biodegradation of clay minerals under the influence of cyanobacterial-actinomycetal associations

The capacity of associations of cyanobacteria and actinomycetes to transform the structure of clay minerals (kaolin, vermiculite, mica, and montmorillonite) was experimentally revealed. First, easily weatherable vermiculite and biotite were transformed. The rate of transformation of micas to mixed-layered minerals depended on their structure: trioctahedral mica (biotite, the component of vermiculite) was changed much faster than dioctahedral mica (the component of kaolin). The lattices of all the phyllosilicates were altered (disordered and disaggregated) under the influence of the cyanobacterial-actinomycetal associations.     

广西水耕人为土黏粒矿物组成及其空间分布特征

黏粒矿物影响着土壤理化性质，可指示成土因素特征和土壤发生发育过程/强度，也是中国土壤系统分类的基层单元土族矿物学类型划分的重要依据。本研究选择了广西不同纬度和成土母质的18个代表性水耕人为土的剖面，应用X射线衍射（XRD）方法分析了其典型水耕氧化还原层（Br层）的黏粒矿物组成及其空间分布特征，并确定了其中“黏质”剖面的土族控制层段矿物学类型。结果表明：（1）供试土壤的黏粒矿物主要包括高岭石、伊利石、三水铝石、1.42 nm过渡矿物、蒙脱石和蛭石等，依次分别出现在100%、88.9%、72.2%、61.1%、44.4%和38.9%的剖面中。（2）黏粒矿物组成在纬度空间分布上具有明显规律性特征。随着纬度降低，土壤黏粒中的高岭石增加，伊利石、蒙脱石、1.42nm过渡矿物逐渐减少；纬度＞23°N区域内，成土母质对黏粒矿物组成影响明显。（3）纬度23°N是黏粒矿物组成和土族矿物学类型分界线，＜23°N区域，黏粒矿物均以高岭石为主，是“黏质”剖面的土族控制层段的主要矿物学类型；＞23°N区域，黏粒矿物组成以高岭石、蒙脱石、伊利石或1.42 nm过渡矿物为主，因成土母质不同而异，“黏质”剖面的土族控制层段矿物学类型包括高岭石混合型、混合型和伊利石型。     

中国亚热带土壤的1.4nm过渡矿物: 综述

This paper is a review of some advances in the studies on 1.4-nm intergrade mineral of soils in subtropical China. 1)1.4-nm intergrade mineral occurs ubiquitously in soils of subtropical China. The 1.4-nm mineral in red soil and yellow soil is mainly 1.4-nm intergrade mineral, and in acidic yellow-brown soil (pH < 5.5) is vermiculite alone or 1.4-nm intergrade mineral together with vermiculite. The distribution and the content of 1.4-nm intergrade mineral in the mountain soils are more widespread and higher than those of the corresponding soils in horizontal zone. 2) The interlayer material of 1.4-nm intergrade mineral in these soils appears to be hydroxy-A1 polymers instead of hydroxy-Fe, proto-imogolite or kaolin-like material. There is a significant positive correlation between A1 amount extracted from the soil with sodium citrate after DCB extraction and pH value of the citrate solution after the extraction. The citrate can also extract a certain amount of silicon from the soil, but the silicon may not come from interlayer of 1.4-nm intergrade mineral. 3) It was seldom studied that either vermiculite or smectite did the natural 1.4-nm intergrade mineral come from in soil, or it was commonly thought to come from vermiculite. A recent report has revealed that it can come from smectite. There are some different behaviors between the 1.4-nm intergrade mineral derived from vermiculite and that from smectite. For example, they exert different influences on the formation of gibbsite. The 1.4-nm intergrade mineral derived from smectite may promote the formation of gibbsite in the yellow soil. 4) The type of 1.4-nm minerals in soils. i.e., vermiculite or 1.4-nm intergrade mineral, may be significant to soil properties, such as soil acidity, exchangeable Al, electric charge amount and specific surface area. Therefore, the management for the soil in which 1.4-nm mineral is mainly 1.4-nm intergrade mineral or vermiculite should be dealt with differently.     

鄂湘两省山地土壤粘粒矿物的研究──Ⅲ．神农架自然保护区北坡土壤的粘粒矿物与表面化学特性

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     

小兴安岭山地暗棕色森林土粘土矿物学特性

本文研究了温凉湿润地区不同地形条件下花岗岩母质上的山地暗棕色森林土土壤链的矿物风化.结果表明,由阳坡岗顶、中部到阴坡下部,酸性淋溶由强变弱.原生铝硅酸盐矿物蚀变为次生的粘土矿物:黑云母酸-弱酸性→二八面体Al(层间)蛭石弱酸-中性→Al绿泥石;微斜长石→蒙皂石;斜长石弱酸性→高岭石或蒙皂石一高岭石类矿物的混层物.在针阔混交林作用下,A层腐殖酸与铝、铁络合,铝蛭石化过程弱.AB和B层黑云母和长石蚀变强,矿物晶层间羟基铝积累,阳坡岗顶Al(层间)蛭石和蒙皂石化,形成了较高的土壤潜在酸度;阴坡下部除Al蛭石外,并有成土Al绿泥石形成,潜在酸度低.含有蒙皂石的C层,层间铝有积累.矿物蚀变和晶层Al转移,是山地暗棕色森林土酸度的主要来源.红松林类型和林木生长情况与土壤粘土矿物学特性及其化学环境条件密切有关.     

The weathering of ferruginous chlorite in a podzol from argyllshire,Scotland

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.     

Mineralogy of a podzol formed in sandy materials in northern denmark

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.     

Les vermiculites hydroxy-alumineuses du Massif Armoricain (France) approches mineralogique,microanalytique et thermodynamique

Hydroxy-aluminous vermiculites have been identified in samples of soils and weathering products from the Armorican Massif of France by a combination of mineralogic, microanalytic and thermodynamic techniques.The hydroxy-aluminous vermiculites behave originally as intergrades between vermiculites sensu stricto and chlorites. The interlayered aluminum responsible for the intergrade behaviour cannot be removed by means of ammonia oxalate but can be by sodium citrate. After such a treatment the mineral loses its intergrade behaviour and acquires the behaviour of sensu stricto vermiculite. The extracting solution contains 12 mg of aluminum per gramme of clay in the studied sample.Further evidence on the nature of the aluminous vermiculites follows from microanalysis in situ. Such in situ quantitative microanalysis makes it possible to establish the structural formulae of minerals. This technique has been applied to weathering products of micas. The data obtained indicate that these weathering products are vermiculites and that one part of the aluminum must be in interlayer positions.The thermodynamic study of equilibrium between waters and aluminous vermiculites needs to be set in a multidimensional space Rⁿ. In such space the chemical composition of a water is represented by one point. Waters in equilibrium with a given mineral are situated in a (n ? 1) dimension hyperplan. For a given population of waters and minerals a program can calculate water-hyperplan distances. The use of this program shows that one part of the examined waters is compatible with the equilibrium with aluminous vermiculites.     

中国土壤胶体研究 Ⅵ.西藏高原几种主要土壤的粘土矿物组成和演变

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。     

Source minerals and formation of partially interlayered vermiculites in Dystrochrepts derived from Tertiary sediments

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.     

中南地区几种地带性土壤的胶体表面性质与14×10-10m矿物

本文研究了中南地区不同纬度带花岗岩母质发育的黄棕壤、红壤、砖红壤的胶体表面性质与粘土矿物组合、14×10^-10m矿物、氧化物的关系。结果表明:(1)黄棕壤、红壤、砖红壤粘粒的阳离子交换量、比表面和内表面占总表面的比例依次减小,这与其高岭石、粘粒氧化物含量依次增加,14×10^-10m矿物含量依次减少有关,且也与14×10^-10m矿物在黄棕壤中主要是蛭石,在红壤中主要是14×10^-10m过渡矿物,砖红壤不含14×10^-10m矿物的结论相符合。(2)在其他矿物类型和含量相近下,14×l0^-10m矿物是蛭石的土壤与14×10^-10m矿物是14×10^-10m过渡矿物的土壤相比,前者的阳离子交换量、比表面、内表面占总表面的比例比后者高些,但土壤的活性酸度弱些,交换性铝含量比后者低些。     

贡嘎山海螺沟冰川退缩区土壤序列矿物组成变化

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。     

Mineralogical composition of the clay fraction in acid brown forest soils under tea plantations subjected to the long-term mineral fertilization in Russian subtropics

Swelling minerals of the montmorillonite group predominate in the clay fraction of acid brown forest soils under tea plantations; illite and quartz are present in smaller amounts; small amounts of chlorite-like structures are also found. A decrease in the content of swelling mineral and a deterioration of their crystallization degree (especially in the upper horizons) take place upon the long-term application of mineral fertilizers at high rates; also, the accumulation of illite takes place. These processes attest to the beginning of degradation and/or removal of montmorillonite minerals (the most finely dispersed and hydrophilic clay minerals) under the impact of a significant decrease in pH because of the high rates of physiologically acid fertilizers in combination with illitization under the impact of potassium application.     

Fixation of radiocaesium traces in a weathering sequence mica → vermiculite → hydroxy interlayered vermiculite

Radiocaesium fixation in soils is reported to occur on frayed edge sites of micaceous minerals. The weathering of mica in acid soils may therefore influence the Cs⁺ fixation process and thereby the mobility of the radiopollutant. We produced a laboratory weathering model biotite → trioctahedral vermiculite → oxidized vermiculite → hydroxy interlayered vermiculite (HIV) and quantified the Cs⁺ fixation of each mineral both in a fixed K⁺–Ca²⁺ background and in acid conditions. The transformation process was achieved through K depletion by Na-tetraphenylboron, oxidation with Br₂ and Al-intercalation using NaOH and AlCl₃. In a constant K⁺–Ca²⁺ background, vermiculite fixed 92–95% of the initial ¹³⁷Cs⁺ contamination while biotite and HIV fixed only 18–33%. In acid conditions, the interlayer occupancy by either potassium (biotite) or hydroxy-Al groups (HIV) strongly limited Cs⁺ fixation to 1–4% of the initial ¹³⁷Cs⁺ contamination. Cs⁺ fixation occurred on vermiculitic sites associated with micaceous wedge zones. Though both oxidized and trioctahedral vermiculites fixed similar Cs⁺ amounts in a constant K⁺–Ca²⁺ background (92–95%), the oxidized vermiculite retained much more radiocaesium in acid conditions (78–84% against 54–59%), because of its dioctahedral character.     

Hydroxy-Al complexes of montmorillonite and vermiculite and identification of intergrades of montmorillonite-chlorite and vermiculite-chlorite in soils

Much evidence has indicated that the occurrence of montmorillonite and vermiculite containing Al-interlayers is very common in solis, particularly acid soils. Viewed in the light of soil clay minerology, it would be required to investigate the properties of their original minerals. For the latter purpose, the Al-interlayer has been removed prior to the Mg-glycerol,K-saturation and heating tests for identification of montmorillonite and vermiculite. Its removal has been accomplished in sevsral ways; KOH plus KCl (1), NH₄F, KCl plus HCl (2), Na-citrate (3),400C de hydroxylation-NaOH (4) dissolution. Although these methods are effective for the removal of Al-interlayers, they seem drastically to affect the minerals or are time-consuming. Inthe course of the study of hydroxy-Al interlaid complexes of expanding 2:1 layer lattice clay minerals, the authors have noticed the difference between the (001) spacings of hydroxy-Al complexes of montmorillonite and vermiculite; the former exhibited the 20 A basal spacing at room temperature against the 14 A spacing of the latter. This difference might be useful for differentiating montnmorillonite-chlorite intergrades in soils.     

Mineral Composition and Weathering of Soils Derived from Xiashu Loess

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