不同母质黑钙土黏粒矿物组成研究

以黄土母质和红土母质发育的黑钙土为研究对象,采用化学分析及X射线分析,对同一气候和地理位置条件下的2种母质黑钙土的黏粒矿物组成及其差异进行研究,并探讨其演化机制.结果表明:2种母质黑钙土的黏粒矿物均以2:1型矿物为主,黏粒矿物组成一致性高,均含有蒙脱石、伊利石、蛭石、高岭石和石英.但各层次间衍射峰的强度以及部分衍射峰位置略有变化,红土母质黑钙土底层不存在蒙脱石,表层以绿泥石为主,而黄土母质黑钙土在底层存在绿泥石,在成土中后期可能转化为蛭石.红土母质黑钙土与黄土母质黑钙土相比,高岭石衍射峰强度更强,伊利石强度减弱,且随着土层深度的增加,减弱趋势更为显著,说明红土母质在成土早期,气候湿热,土壤风化较为强烈.     

西南典型水耕人为土诊断层黏土矿物特征

选择我国西南地区代表性水耕人为土剖面,对其主要诊断层黏土矿物组成特征进行研究。采用沉降吸管法提取土壤黏粒,将其进行Mg2+饱和、Mg2+饱和加甘油处理、K+饱和加热550℃三种处理后,分别在X-射线衍射仪扫描,对所获图谱进行黏土矿物组成鉴定。实验结果显示西南地区代表性水耕人为土其诊断层黏粒黏土矿物组成特征主要为蛭石,高岭石,伊利石,混层矿物等。含少量其它黏土矿物如三水铝石,蒙脱石等。与旱地土壤比较,水耕人为土的黏土矿物组成有明显的不同。不同发育时间和水耕熟化的水耕人为土,其黏土矿物组成和数量上也有明显差异,研究结果对黏土矿物在水耕人为土系统分类上的应用具有一定的理论意义。     

东北黑土耕层土壤黏粒矿物组成的区域差异及其演化

在东北黑土耕层土壤小于2μm黏粒的化学组成和X衍射分析基础上,对不同纬度的15个黑土的黏粒矿物组成和空间差异进行研究,并探讨了其影响因素及演化机制。结果表明:东北黑土耕层土壤黏粒矿物属伊利石—蒙伊混层矿物类型,但其组合因区域不同有所差异,高纬度黑土为伊利石—蒙伊混层型,低纬度黑土则为蒙伊混层—伊利石—蛭石型。影响黏粒矿物空间差异的主要因素有降水、温度、作物类型。由于这些因素在空间上的显著差异,使黑土黏粒矿物演化序列处于伊利石向蒙伊混层或蛭石的不同阶段,导致东北黑土黏粒矿物组成在纬度上形成显著区域差异。     

南极半岛海洋气候区的土壤Ⅶ. 矿物学特性

南极海洋气候区岩石风化和土壤形成过程中有明显的原生矿物蚀变作用和自生矿物成矿作用。本文以粗骨寒冻灰化土和石灰性扰动冻土两种有代表性的土壤类型为例,阐述了本区土壤矿物学特征。指出铝氧化物、绿泥石、碳酸盐是本区玄武岩类风化物质上发育土壤中的主要自生矿物类型,蒙脱石、特别是绿泥-蒙脱石混层矿物是南极海洋气候区土壤粘粒部分的特征矿物。不同土壤由于成土环境、成土过程、成土历史的差异,其土壤物质的矿物学组成、含量、形态、分布具有明显不同。土壤发生性铁氧化物与成土作用和土壤过程密切相关,其矿物类型、含量、形态特征、分布模式在不同的土壤中明显不同,是表征土壤发育程度与剖面形态表达的有效指标。     

太湖地区水耕人为土中漂白层的成因探讨

采集太湖地区4个具有漂白层的水耕人为土剖面(E-A1、E-A2、E-A3、E-A4)及1个发育于相同母质上的一般水耕人为土剖面作为参照(Ref),描述了土壤剖面的形态特征,分析了土壤颗粒组成、黏粒矿物组成、铁氧化物以及大量和微量元素等,并探讨了漂白层成因。5个剖面土壤颗粒组成以粉粒为主,在60%~75%之间,且剖面中各层次变异系数较小,小于10%;大量元素和微量元素在剖面各层次间变异系数也小于10%,指示漂白层与上覆和下伏土层发育在相似物质来源的土壤母质上;而E-A1剖面漂白层中较高的粉粒含量(75.04%)、较大的中细粉粒和中细粉粒/粗粉粒比值的变异系数(38.05%、61.85%)表明该剖面母质具有不均一性。说明E-A2、E-A3、E-A4、Ref剖面土壤性质的变化主要是由于成土作用形成的,而E-A1剖面土壤的性质变化除受成土作用影响外,还受沉积环境的影响。E-A2、E-A3、E-A4剖面的漂白层中蒙脱石和蛭石、粉粒和粗粉粒、SiO2、CaO、Zr等含量高于上下土层,而水云母和绿泥石、游离铁、Al2O3、Rb、Li、Ba、稀土元素(Rare earth element,REE)等则相反;同时,参照剖面亦有与E-A2、E-A3、E-A4剖面类似的特点,只是漂白作用出现在耕作层,不能定义为漂白层;而E-A1剖面的部分性质则显示出空间上的不一致性,其粉粒含量并非漂白层最高,而是随剖面土层深度向下越来越大。这些变异表明,太湖地区水耕人为土漂白层的形成,可以由黄土性泻湖相沉积物经过水耕过程中水分的周期性淹水和排干,通过机械淋洗和活性铁的淋溶而形成(剖面E-A2、E-A3、E-A4),也可以是母质沉积的过程中受湖水水面升降,导致机械淋溶,然后水耕过程叠加活性铁的淋溶而形成(剖面E-A1)。     

泰山山前平原土地利用方式对潮棕壤黏土矿物组成的影响

对泰山山前平原潮棕壤区小麦/玉米轮作农田、杨树林地和荒草地三种土地利用方式黏土矿物组成进行研究,探究不同土地利用方式下黏土矿物组成的变异规律与影响因素。通过野外样地调查、室内土壤黏粒提取及其黏土矿物的X-射线衍射图谱分析等方法分析黏土矿物组成及相关土壤指标。结果表明:三种利用方式土壤以伊利石(包括结晶好伊利石和结晶差伊利石)为主要矿物,次要矿物为蛭石和高岭石,混层矿物为少量矿物组成。荒草地表层土壤伊利石含量最高(75.8%),分别较农田和林地土壤提高26.4%、23.6%。下层土壤伊利石含量较表层土壤有显著降低,荒草地土壤的降低幅度较大。结晶好伊利石含量表征土壤的风化程度,荒草地、林地、农田土壤矿物的风化作用依次增强。蛭石含量在下层土壤的差异显著且较表层土壤含量高,含量由高到低依次为荒草地、农田、林地。荒草地土壤有机碳含量和钠质分散有机无机复合体含量较林地和农田土壤有显著降低。不同利用方式土壤黏粒中伊利石含量与蛭石含量之间相互转化,受土壤速效钾含量的调控。荒地建议开垦为林地或草地,促进土壤有机碳保持和有机无机复合体形成,抑制黏土矿物在土壤剖面的迁移。     

汉江上游郧县一级阶地发育土壤的诊断层特征及分类

阐明秦岭南侧北亚热带环境中以黄土为母质所发育土壤的诊断层特征及其对土壤分类的意义。选择位于汉江上游郧县前坊村的一级河流阶地土壤剖面为研究对象,对其粒度、磁化率、元素、矿物及结构进行了研究。结果表明,汉江河谷分布的土壤具有A-AB-Bt1-Bt2-BC-C剖面形态;Bt层具有“黏化层”的标志特征,并呈现黏磐的诊断特征,其黏化程度与中国典型黏磐湿润淋溶土有良好的可比性;黏土矿物以伊利石为主,少量高岭石,风化程度处在脱钙作用的后期阶段,尚未出现显著的富铝作用,达到中等成壤的强度;土壤类型可归为黏磐湿润淋溶土。     

南京地区水稻土中固定态铵与伊利石的相关性

本文以南京地区长城岗和泉水两个水稻土剖面为研究对象,在利用Silva-Bremner法测定土壤全样和3个粒级(黏粒、粉粒和细砂粒)的固定态铵含量、利用X-射线衍射仪测定矿物成分的基础上,讨论了固定态铵含量与粒级以及矿物种类的关系.结果认为,两个剖面在以下几个方面具有共性:①在黏粒、粉粒和细砂粒3个粒级中,黏粘粒含量与固定态铵含量的关系最为密切,相关系数分别为0.68和0.64;②在黏粒中的伊利石、高岭石和蒙脱石3种主要矿物中,伊利石含量与固定态铵含量相关性最好,相关系数分别为0.50和0.49;⑨对于全样来说,其中的伊利石含量与同定态铵含量呈极显著正相关,相关系数分别为0.68和0.66.这些数据充分说明,伊利石是南京地区水稻土中固定态铵赋存的最主要载体.     

海拔与岩性变异对石灰岩发育土壤黏土矿物组成的影响

用X射线衍射法研究了中亚热带区海拔、岩性变异对石灰岩发育土壤黏土矿物组成的影响。结果表明:在海拔约2 000 m的重庆金佛山山顶区,灰黑色钙质页岩石灰岩发育的黑色石灰土,矿物组成复杂,除伊利石为主外,还有少量蛭石、绿泥石、高岭石和蒙脱石,有一定量的母质残留矿物(滑石和滑间皂石);由砂页岩和灰岩互层母质发育的山地黄棕壤,以蛭石为主,伊利石和高岭石其次,有三水铝石和弱结晶针铁矿。在金佛山中下部(600~1 200 m),石灰岩发育的黄色石灰土以蛭石或伊利石为主,有一定量的高岭石,普遍出现针铁矿。湖南怀化盆地海拔200多米,纯灰岩发育的红色石灰土为伊利石、蛭石和高岭石(含埃洛石)组合型,有结晶好的针铁矿和少量赤铁矿。海拔显著影响高岭石含量、针铁矿结晶度,海拔降低时高岭石含量增加,针铁矿结晶度提高。在金佛山山顶区,石灰岩母质岩性和微地形变异对土壤成土过程和黏土矿物组成影响显著。     

水耕年限对黄棕壤发育的水稻土的表面化学性质的影响

利用采自江苏省农业科学院果园的旱地黄棕壤(对照)和由黄棕壤发育水耕20年和60年的水稻土,研究了土壤黏粒和粉粒的矿物组成,胶体和土体的化学性质随水耕年限的变化.粉粒的X-射线衍射图谱表明,3种供试土壤发育母质相似,胶体的矿物组成随水耕年限的变化不大.动电电位和表面负电荷的测定结果也表明,胶体表面化学性质未发生明显变化.随水耕年限增加,土壤黏粒含量降低,导致土体性质发生明显变化,土壤CEC和结构电荷量随水耕年限增加显著减少.     

Transformation of clay minerals in nanoparticles of several zonal soils in China

Purpose

Clay minerals significantly affect the physical, chemical, and biological processes of soils. They undergo spontaneous modification and transformation depending to the climatic conditions. Information concerning the compositions and transformation of clay minerals in nanoparticle colloids (NPs) (25–100 nm) is severely lacking. Studying clay mineral transformation is important approach to understand soil formation. This study was conducted to determine the transformation sequence of clay minerals in several zonal soil NPs.

Materials and methods

Four soils (Haplustalf, Alf-1; Hapludalf, Alf-2; Hapludults, Ult-1 and Ult-2) were collected from B horizons developed under three different climatic zones of China. Alf-1 (36° 05′ N and 117° 24′ E) was located under a warm temperate zone and Alf-2 (30° 38′ N and 115° 26′ E), Ult-1 (29° 13′ N and 113° 46′ E), and Ult-2 (19° 27′ N and 109° 17′ E) under a subtropical zone. The clay particles (<?2000 nm) (CPs) and nanoparticles (25–100 nm) (NPs) of tested soils were separated. The element composition of CPs and NPs was identified by microwave digestion method. The mineralogy and chemical bonding of clay minerals were studied by X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FT-IR).

Results and discussion

With decreasing latitude, NPs and CPs showed that the molar ratio of SiO₂ to Al₂O₃ trends to diminish, indicating the phenomenon of desilication and allitization in the tested soils. XRD analysis revealed that the main clay mineral of Alf-1 NPs was illite, followed by vermiculite, kaolinite, and kaolinite interstratified minerals (KIMs). The clay minerals of Alf-2, Ult-1, and Ult-2 NPs were dominated by kaolinite (and KIMs), followed by illite, with a little content of hydroxyl-interlayered vermiculite (HIV) in Ult-1 NPs and trace content of gibbsite in Ult-2 NPs. With decreasing latitude, vermiculite and HIV decreased in NPs. When compared to CPs, smectite as well as illite-vermiculite mix-layer mineral (I-V) and illite-HIV mix-layer mineral (I-HIV) were not detected in NPs. The analysis of d060 region by XRD showed that with decreasing latitude, the main clay minerals in NPs were dioctahedral minerals (e.g., illite or kaolinite). These clay minerals resulted from the transformation of trioctahedral minerals in CPs. The disappearance of 2:1 swelling minerals and trioctahedral minerals showed that the NPs were more susceptible to weathering than CPs.

Conclusions

With decreasing latitude, the transformation of clay minerals followed the sequence of illite?→?HIV?→?kaolinite?→?gibbsite in tested NPs.

     

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。     

Composition of clay minerals and their pedogenetic and taxonomic implications for Stagnic Anthrosols derived from different parent materials in Hunan Province,China

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.

     

Potassium release on drying of soil samples from a variety of weathering regimes and c clay mineralogy in China

Thirty two soil samples from China were analyzed for exchangeable K before and after drying. Most soil samples were higher in exchangeable K after air-drying and ovendrying (60°C) than when wet. Soil clay minerals, especially clay-size mica, affected K released in air-dry and oven-dry samples. According to composition of clay minerals of air-dried samples, five classes were recognized. Soil samples with high mica and montmorillonite have the highest exchangeable K. Samples that contained higher kaolinite than mica had lower exchangeable K. Samples with higher kaolinite than quartz and mica had still lower exchangeable K. Samples of sandy soils contained very low exchangeable K. When quartz was the main mineral, the samples that had kaolinite and gibbsite as the main clay minerals had very low exchangeable K. The degree of weathering (weathering mean) bore an inverse relationship to the amount of K released on drying in air or at 60°C. Udults and Udalfs (Red Earths) of southeastern China, because of their high K release on being dried, are inferred to have received fine mica from the Western Desert dust rainout, reported to Liu et al. (1981).     

中国福建省土壤的主要粘土矿物

The clay minerals of more than 200 soil samples collected from various sites of Fujian Province were studied by the X-ray diffraction method and transmission electron microscopy to study their distribution and evolution.Montmorillonite was found in coastal solonchak,paddy soils derived from marine deposit,lacustrine deposit and river deposit,and some lateritic red soil,red soil and yellow soil with a low weathering degree.Chlorite existed mainly in coastal solonchak and paddy soil developed from marine deposit.1.4nm intergradient mineral appeared frequently in yellow soil,red soil and lateritic red soil.The content of 1.4nm intergradient mineral increased with the decrease of weathering degree from lateritic red soil to red soil to yellow soil.Hydrous micas were more in coastal solonchak,paddy soils derived from marine deposit,lacustrine deposit and river deposit.and puple soil from purple shale than in other soils.Kaolinte was the most important clay mineral in the soils iun this province.The higher the soil weathering degree,the more the kaolinite existed.From yellow soil to red soil to lateritic red soil,kaolinite increased gradually,Kaolinite was the predominant clay mineral accompanied by few other minerals in typical lateritic red soil. Tubular halloysite was a widespread clay mineral in soils of Fujian Province with varying quantities.The soil derived from the paent rocks rich in feldspar contained more tubular halloysite.Spheroidal halloysite was found in a red soil and a paddy soil developed from olivine basalt gibbsite in the soils in this district was largely“primary gibbsite” which formed in the early weathering stage.Gibbsite decreased with the increase of weathering degree from yellow soil to red soil to lateritic red soil.Goethite also decreased in the same sequence while hematite increased.     

Clay minerals in a soil chronosequence derived from basalt on Hainan Island, China and its implication for pedogenesis

A soil chronosequence consisting of six profiles formed on quartz tholeiite basalt ranging in age from 10,000 years to 1. 8 Million years (My) was studied here. Soil clays were identified using XRD diffractogram decomposition methods for samples obtained from the A and C horizons of profiles. The results showed that kaolinite minerals dominated in all the clay fractions. Gibbsite was prominent in the C horizons in the soils from older rocks. Clays in the A horizon of relatively young soils showed an initial stage of illite formation, followed by smectite mixed layer minerals (illite-smectites and then vermiculite-illite) and finally by vermiculite. The initial presence of illite is interesting as there is no magmatic micaceous or phyllosilicate phase in these basalts and the formation of illite we attribute to a secondary process, probably created by alkali transport by plant materials. The change in 2:1 clay mineralogy reflects the overall change in Si/Al ratios in the soils over longer periods of weathering. In all cases gibbsite is more abundant in the C horizons than the A horizons. The difference in gibbsite content between the A and C horizons we attribute to plant transport of siliceous phytolite material to the surface. Continued high rainfall over long periods of time removed the alkali faster than the plants could bring it to the surface, which led to continuous lowering of 2:1 minerals from younger to older in the soil chronosequence. Nevertheless a 2:1, silica-rich mineral persists in the clay assemblages although in very minor amounts.     

The relationships of the clay mineral suites to the parent rocks of eight soil profiles in Sarawak,Malaysia

The clay mineralogy of eight selected soil profiles developed on acid igneous, pyroclastic and sedimentary rocks was investigated. The effects on the clay mineralogy of the parent-rock mineralogy and physical conditions within each soil profile were evaluated.The results indicate that the mineralogies of the parent rocks control the type of clay minerals formed in Sarawak. In the soils derived from pyroclastic and coarse-grained acid igneous rocks without muscovite, the clay-mineral suites consist almost exclusively of kaolinite and gibbsite with small amounts of goethite. In contrast, in the soils developed from fine-grained acid igneous and sedimentary rocks with muscovite, the clays contain relatively large amounts of interstratified mica-vermiculite and chlorite-vermiculite in addition to gibbsite and/or kaolinite. The presence of gibbsite in these soils depends on the presence of plagioclase feldspar in the parent rock.     

九宫山土壤剖面中黏土矿物的组成特征

以湖北省九宫山的4种垂直地带性土壤为对象,研究其剖面层次的黏土矿物组合和铁、铝氧化物的特征,揭示山地土壤中黏土矿物的变化特点。结果表明,随海拔升高,土壤中黏土矿物类型从以高岭石为主,逐渐变为以14.0?矿物、伊利石及三水铝石为主,有从1︰1型向2︰1型矿物过渡的趋势;不同层次的土壤中黏土矿物类型和相对含量变化明显;土壤随垂直高程的升高,其中游离态铁、铝减小,非晶形和络合态铁、铝增加,各种形态铁、铝氧化物的总量也增加。     

CLAY MINERAL DISTRIBUTION AND ORIGIN IN THE SOIL TYPES OF ISRAEL

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.