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1.
本文分析了粤北武水、北江、横石水和连江各级阶地及河漫滩上各时代沉积物发育土壤的粘粒矿物和原生矿物。结果表明,不同河流流经地区不同,物质来源不同,其矿物组成有别;同一河段,形成于早更新世的三级阶地(T3)上的土壤矿物组成与形成较晚的各级阶地差异甚大,这是母质来源和风化成土条件不同所致;二级阶地(T2)、一级阶地(T1)及河漫滩(T0)上的土壤矿物相似,只是风化程度有异,随着阶地升高,形成年代愈老,富铝化程度愈强烈;但各级阶地之间差异程度不均等,T2至T1之间变幅大,T1至T0之间差异较少,这是时间因素和古气候波动性叠加所致。  相似文献   

2.
太湖流域水稻土的磁化率剖面   总被引:3,自引:0,他引:3  
土壤磁学是一门新兴的土壤学分支学科。它以研究土壤磁性为中心内容,把现代磁学理论以及磁测、磁查和磁诊断等研究手段和方法应用到土壤学中来[2]。土壤磁性的强弱,可用磁化率作为指标。土壤磁化率的大小,主要决定于含铁矿物的种类和数量,特别是强磁性矿物(亚铁磁性的磁铁矿Fe2O3·FeO和磁赤铁矿γ-Fe2O3)的数量。  相似文献   

3.
Over 300 samples of London Clay from twenty-one widely scattered sample locations in the London and Hampshire Basins were to be examined in detail by X-ray diffraction techniques. The quantitative method of Schultz (1964) was chosen as being most suited for the analysis of the samples. Series of tests designed to investigate the reproducibility characteristics of the method were conducted. These showed that the sampling, sample preparation, and interpretation procedures used all introduced cumulative reproducibility errors of roughly equal magnitude which completely overshadowed errors introduced by machine-response variation. It was also established that minerals whose contents were below 10 percent of whole sample failed to be consistently quantitatively estimated. The accuracy of this method of analysis depended heavily on Schultz's quoted ‘intensity factors’ which were involved in the calculation of individual mineral contents. The authenticity of these factors with regard to the London Clay suite of minerals was checked by comparing accurately determined mineral percentages of six standard London Clay samples with the results obtained by use of the Schultz procedure and factors. The method was found to be basically sound although the intensity factors for quartz, total clay minerals, carbonates, and illite had all to be slightly adjusted. The accurate quartz percentages were established by three different X-ray diffraction techniques and the carbonate percentage checks were accomplished by specially designed wet chemical methods. The total clay mineral and illite contents checks were carried out by back-calculation of the Al2O3, and K2O percentages as determined from full wet chemical analysis. Using the adjusted factors, quartz percentages are estimated accurate to ±6 percent, total clay minerals to ±7 percent, carbonate percentages to ±1.5 percent, and illite contents to ±4 percent of the whole rock.  相似文献   

4.
第四纪红土的磁性与氧化铁矿物学特征及其古环境意义   总被引:14,自引:1,他引:13  
卢升高 《土壤学报》2000,37(2):182-191
应用矿物磁测,X-衍射和电镜技术对浙江省第四纪红土的磁性与氧化铁矿物学特征进行了研究。结果表明,均质层和网纹层的磁化率(χ)、频率磁化率(χfd)、软剩磁(SoftIRM)、非滞后剩磁(ARM)、饱和等温剩磁(SIRM)和剩磁矫顽力((Bo)ck)等磁性参数存在明显差异,均质层的磁化率和饱和等温剩磁分别是网纹层的6倍和4倍;第四纪红土的磁化率主要由风化成土作用产生的超顺磁性颗粒(SP)和稳定单畴颗  相似文献   

5.
The system SiO2 -AlOOH-Fe2 O3 -H2 O is used to show certain short-comings in the use of single minerals to index weathering stages. An alternative (analogous to the metamorphic facies concept) is proposed in which three stages are recognized, one of which can already be defined in terms of mineral assemblages, while the two earlier stages should eventually prove open to this treatment.  相似文献   

6.
The mineralogical composition of clays (< 2μm) in representative profiles of all soil types of Israel was investigated. The soils were classified according to their clay mineral assemblages into three groups. I. Montmorillonitic soils. Montmorillonite is the dominant mineral and exceeds 65 per cent of the total minerals found; each of the other minerals comprises less than 15 per cent. 2. Montmorillonitic-kaolinitic soils. The soil clay fractions contain 50-60 per cent montmorillonite and 15-25 per cent kaolinite, generally adding up to more than 75 per cent of the clay fraction. 3. Montmorillonitic-calcitic soils. The clays contain more than 10 per cent calcite. Montmorillonite is the dominant clay mineral (except for one soil type, mountain rendzina, where calcite is dominant). The first and second assemblages are typical of the soils of the Mediterranean zone, whereas the soils of the desert zone are characterized by the third assemblage. The origin of montmorillonite, kaolinite, and illite, the three main clay minerals, was found to be detritic, as was the origin of palygorskite which was mainly found in the calcite rich soils of the desert zone. The cation exchange capacity of montmorillonite seems to be higher under higher precipitation. Montmorillonite content and cation exchange capacity of the clays were found to be highly correlated. The carbonate content of the clay fraction and the amount of carbonate in the soil were also highly correlated.  相似文献   

7.
富钾植物籽粒苋根系分泌物及其矿物释钾作用的研究   总被引:24,自引:3,他引:21  
应用14 C 同位素示踪技术研究了籽粒苋品种根系分泌物的动态、构成以及对含钾矿物钾素释放的作用。结果表明,具有高效富钾特性的籽粒苋品种, C O2 同化能力强,光合产物向根外分泌的比例大。籽粒苋根系分泌物中的有机酸主要是草酸,占有机酸总量的95 % 以上。不同种属的籽粒苋分泌有机酸的能力不同,一般是 A Dubis> A Retroflexus > A Cruentus 。同一种内,则钾素利用高效型品种一般型品种。钾亏缺处理显著提高光合产物向根外的分泌量。钾利用高效型籽粒苋品种的草酸分泌量明显增加。根系分泌物对含钾矿物有明显的解钾作用。草酸含量与根系分泌物解钾量显著相关,籽粒苋的草酸分泌能力是籽粒苋高效吸收利用土壤钾及富钾特性的重要机理之一。  相似文献   

8.
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   

9.
广西水耕人为土黏粒矿物组成及其空间分布特征   总被引:1,自引:1,他引:0  
欧锦琼  黄伟濠  卢瑛  李博  阳洋  唐贤  贾重建  秦海龙 《土壤》2020,52(6):1290-1297
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...  相似文献   

10.
中国土壤中粘粒矿物的分布规律   总被引:2,自引:0,他引:2  
熊毅  许冀泉 《土壤学报》1964,12(3):266-274
土壤粘粒部分的组成和性质在土壤发生学及土壤肥力特性的研究中都占很重要的位置。过去认为土壤粘粒中的无机物都是非晶形的,自从伦琴射线衍射应用到土壤学研究中后,大家都公认土壤粘粒部分含有晶形结构的矿物。  相似文献   

11.
The value of modem commercial DTA equipment in the identification and determination of anhydrous carbonate minerals can be greatly improved by incorporating a controlled-atmosphere (carbon dioxide) technique. The unproved peak definition and increased height enables the detection of carbonate minerals at concentrations of the order of 0.25 per cent by weight in a 50 mg sample. Further, the related changes in temperature of the decomposition reaction peaks provide additional information for the identification of carbonate mineral reactions. The method has particular application in mineralogical and pedological investigations.  相似文献   

12.
The magnetic susceptibility of soil minerals is discussed, and in particular that of the ferrimagnetic minerals, maghemite, magnetite, and the titanomagnetites since one or more of these usually dominates soil magnetic properties. The magnetic susceptibility of soil depends on the shape, size, and concentration of these minerals as well as on the method of measurement. Measurements performed in a weak alternating magnetic field are the most reliable. The identification, formation, and occurrence of soil maghemite is considered in detail since it is usually of pedogenic origin and occurs in (magnetically) detectable amounts in most soils. Moderate concentrations (>1 per cent) of magnetite or titanomagnetite in soils may be accurately measured if some of the material is first magnetically separated and its susceptibility determined. An example is given of the use of susceptibility measurements. Pedogenic maghemite may be determined in soils developed from parent materials of low susceptibility. A very rough value of 8.8 × 10?4 m3 kg?1 is suggested for the mass susceptibility of such maghemite (excluding magnetic concretions). Although susceptibility has been suggested as an indicator of soil forming processes, this is only possible within an area containing fairly uniform parent material.  相似文献   

13.
豫北第四纪沉积物的矿物特征   总被引:1,自引:0,他引:1  
豫北平原属于黄淮海平原的一部分,位于太行山洪积-冲积扇以东的黄河、漳河之间,是河南新乡和安阳两地区的主要粮棉产地。豫北平原除部分地区是黄土缓丘和山前洪积冲积物外,大部分由黄河、漳河、沁河等现代河流沉积物所组成,其中沁河沉积物、黄土、次生黄土分布在豫北平原西部,漳河沉积物分布在豫北平原北部,而中部和东部则为大面积的黄河河流沉积物。为配合黄淮海平原中豫北平原的治理及南水北调工程中线的选线间题,我们曾对豫北地区各种沉积物上所发育的土壤进行分析,有关华北平原的土壤已有详细专著(熊毅等1965),本文仅就豫北平原地区土壤的矿物性质作简要讨论。  相似文献   

14.
三江平原白浆土发生学特性   总被引:1,自引:1,他引:1  
本文对三江平原三个典型白浆土剖面的理化性质、土壤微形态和矿物学性质的研究,探讨了白浆土的发生学特性。土体中Zr/Sr和Ti/Zr比率的变异系数表明,所研究的土壤剖面其成土母质岩性是连续的。典型白浆土具有一个松软的表土层、一个漂白层和一个相当厚的粘化淀积层。研究还表明,粘粒的悬浮迁移是白浆土的主要成土过程。表层和白浆层在成土过程中有Fe-Mn结核形成,且是原地形成的,其Fe、Mn明显源于原生矿物的风  相似文献   

15.
The mineralogy of soils and parent rocks of the Iremel Ridge has been studied by the methods of micromorphology, laser diffraction, computed X-ray microtomography, and X-ray fluorescence analysis. In hard rock and soil, the major minerals have been identified: quartz, illite, and a chlorite-group mineral (Fe analogue of sudoite), as well as accessory minerals: monazite, xenotime, rutile, zircon, and florencite. It has been found that chlorite, illite, and quartz are present in all horizons of the studied peaty-podzolic soil. Insignificant amounts of mixed-layered mineral and kaolinite could be suggested in the T and EL horizons of peaty-podzolic soil. The mixed-layered mineral is most probably of soil origin, which is related to the transformation of illites inherited from the parent rock under acidic conditions.  相似文献   

16.
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。  相似文献   

17.
An explanation is offered for the fact that the toxic levels of molybdenum occurring in the Lower Lias soils of Somerset have not been found in soils of Glamorgan, apparently derived from the same zones of the Lower Lias. This is attributable to the parent rock being free of the abnormally high levels of molybdenum found in Somerset, which in turn probably results from the Glamorgan Lias having been laid down close to the contemporary coastline.
Soils high in molybdenum are to be expected in the Vale of Marshwood (Dorset), but owing to the topography of this district they probably occur in such small pockets as to cause no serious trouble.  相似文献   

18.
昆明地区不同母质对红壤发育的影响   总被引:6,自引:0,他引:6  
趙其国 《土壤学报》1964,12(3):253-265
昆明地区位于云南省中部,为我国西南高原红壤的主要分布区。关于本区土壤形成过程及发生分类等同题,虽然曾有人做过不少工作,但至今仍存在着一些分歧;有人认为本区土壤的形成过程以砖红壤化为主,土壤类型为砖红壤及铁质砖红壤性土[1,2];有人认为棕壤化为本区土壤的主要成土过程,土壤应命名为棕色森林土[4];另有人认为本区土壤属红壤,目前的成土过程为红壤化[5],所有这些意见,均因资料不足而难取得统一。  相似文献   

19.
Silt-sized mineral grains were analysed for their shapes or forms in thin sections of soils using backscattered electron scanning images (BESI) and an image analyzer (Quantimet 720). This work was done with an image-editor and required manual editing of the shape of mineral grains on the display screen of the Quantimet. Shape analysis of coarse and fine silt grains could thus be performed at magnifications of x 240 and x 480.

The shape of the mineral grains could be characterized by five parameters: area (A), perimeter (Pe), largest and smallest Feret's diameters (Fmax and Fmin), lobation ratio (Lr) and indentation ratio (Ir). A relation was found, however, between the APe2 ratio and the Lr and Ir ratios. Consequently, shape analysis of mineral grains can be done by measuring three of the five parameters, i.e. A, Pe and Fmax/Fmin. These parameters, however, are still not be able to reproduce the shape of individual mineral grains and images of them therefore remain necessary.

Several of the 54 mineral grains were found to have different shapes but the same A/Pe2 ratio. An explanation for this phenomenon is given by using a theoretical model in which two-dimensional forms change their shapes from a circle (A/Pe2 = 79) to a line (A/Pe2 = 1). Form separation of mineral grains with the same (A/Pe2) ratio can be done by using the Fmax/Fmin ratio.

The measurement of the shape of the mineral grains, the theoretical model and observation of the micrographs of the individual mineral grains, made it possible to draw a diagram with shape classes which can be used for shape classification purposes. Knowledge gathered in soil micromorphology on shape analysis of pores and soil aggregates has also been used to obtain boundaries of shape classes in the diagram. The present study is intended both as a proposal as to how two-dimensional shape classification can possibly be done, and as a work-model. The boundaries of the shape classes can easily be adjusted if data from forthcoming studies require it.  相似文献   


20.
Abstract

An experiment was conducted in the central region of Malawi to study the relationship of minerals in soil‐plant‐animal systems to enable prediction of mineral status of beef cattle. Soil, forage and tissues (blood, bone and liver biopsy samples) were collected from cows at the same time in February, April, May, October and December for three consecutive years. Brahman x Malawi Zebu cows were supplemented with mono‐ and di‐calcium phosphate, salt and copper (plus cobalt and selenium) boluses.

Bone, liver and serum minerals (calcium, phosphorus, copper and zinc) correlated poorly to specific minerals in either forage or soil. A few minerals could explain more than 16% of their variation in animal tissues. Consequently, it was concluded that correlation coefficients among soil, plant and animal tissues are low or nonexistent. Therefore, until high, significant, reliable and reproducible correlation coefficients are established among soil, plant animal tissues, prediction of mineral status of animals by regression analysis from mineral content of soil or plants is likely to remain imperfect.  相似文献   

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