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1.
不同母质黑钙土黏粒矿物组成研究   总被引:1,自引:0,他引:1  
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.  相似文献   

2.
通过对形态特征、矿质元素含量变化及分布特征、元素的淋溶(或聚积)状况、土壤发育指标等进行分析,探讨了辽宁朝阳凤凰山剖面古土壤序列的土壤发育特征和发育程度。研究结果表明,在凤凰山古土壤剖面中,自地表向下至19.85 m范围内,除现代土壤层S0(0~108 cm)外,还可划分出9个土壤地层,包括5层黄土(L1~L5)和4层古红土(S1~S4)。所有这些土壤地层都是发育在风积粉尘母质上的古土壤,形成时间介于71~423 ka B.P.之间。古土壤的发生与成土母质(粉尘)的沉积同步进行,发育成红色还是黄色的古土壤决定于不同的成土环境条件和粉尘沉积速率的相对大小。在凤凰山古土壤序列中,各层古红土比各层黄土质古土壤经受了更强的风化和淋溶作用,古红土发育程度明显强于黄土质古土壤。5层黄土质古土壤比较,土壤发育程度最弱的是L1层,最强的是L5层;比较4层古红土的发育程度,最弱的是S2层。纵观凤凰山古土壤序列,各个发育不同程度的古土壤交错排列,说明当地成土环境(气候)在423~71 ka B.P.间经过多次波动变化。  相似文献   

3.
元谋盆地古红土的土壤发生学特征及古环境意义   总被引:5,自引:0,他引:5  
选择元谋盆地不同发育年代形成的古红土,探讨了古红土的发生学特性。研究表明,在气候上更有利于早期形成的古红土发生强烈的风化淋溶作用,同时,晚期形成古红土气候湿热程度下降,成土时间也短,故土壤中硅淋溶较弱,铁铝富集程度不强。利用古红土发生学特性,可以推断出元谋盆地从晚新生代的湿热气候经暖干气候演化至现代的干热气候。  相似文献   

4.
【目的】土壤是由大小和形态各异的颗粒构成,各级颗粒包含丰富的黏土矿物演化信息。明确西辽河平原黏土矿物组成及演化特征有助于了解该地区土壤发育程度及肥力状况,为当地土壤资源合理利用提供理论依据。【方法】以西辽河平原分布较多的栗钙土和盐碱土为研究对象,采集表层土壤并分离不同粒级的土壤颗粒(<2、0.45~2、0.1~0.45μm),利用X射线衍射(XRD)和化学分析等方法研究黏土矿物组成及相关土壤指标。【结果】XRD分析结果表明,西辽河平原栗钙土和盐碱土的黏土矿物均以伊利石-蛭石-绿泥石为主,栗钙土中伴有少量高岭石和伊/蒙混层矿物,而盐碱土中含有少量高岭石、蒙脱石和1.4 nm过渡矿物;随粒径减小,栗钙土和盐碱土颗粒中绿泥石、高岭石、蒙脱石(伊/蒙混层矿物)和1.4 nm过渡矿物含量均减少,伊利石和蛭石含量增加;伊利石结晶度在栗钙土、盐碱土以及不同粒级的土壤颗粒中也存在明显差异。盐碱土中伊利石结晶程度较栗钙土弱。随粒径减小,栗钙土和盐碱土中伊利石结晶程度均变弱。化学分析结果表明,西辽河平原盐碱土中Na2O的含量明显高于栗钙土,栗钙土和盐碱土颗粒的风化程度均随粒径减...  相似文献   

5.
辽宁朝阳地区第四纪古红土特性及系统分类研究   总被引:4,自引:0,他引:4  
为弄清北方古红土在中国土壤系统分类中的位置,对辽宁朝阳地区分布的第四纪古红土的特性和系统分类进行了研究。本文首先将古红土看做成土母质,按《中国土壤系统分类检索(第三版)》的原则和方法,讨论了供试古红土剖面的诊断层和诊断特性,并进行了分类检索;又从古红土本身的发生学特征出发,讨论了各古红土剖面的诊断层和诊断特性,并进行了分类检索。研究发现:现行的《中国土壤系统分类检索(第三版)》还不能给古红土一个合适的位置,要解决古红土在中国土壤系统分类中的位置问题,首要任务是建立关于古土壤的诊断标准。  相似文献   

6.
不同土地利用方式下第四纪古红土团聚体的组成比较研究   总被引:1,自引:0,他引:1  
《土壤通报》2020,(3):587-596
以林地、疏林荒草地、荒草地、耕地、埋藏古红土等不同利用方式下的第四纪古红土剖面为研究对象,通过剖面内扣除黏粒的粒度组成、Ti/Zr比值和野外剖面形态观察等方法分析,判定了古红土母质均一性,接着利用湿筛法筛分了供试古红土水稳性团聚体,比较分析了各利用方式下古红土与未经人为利用的埋藏古红土的不同粒级团聚体组成,探讨了不同土地利用方式下的古红土不同粒级团聚体组成变化。研究结果表明:(1)供试古红土的成土母质是均一的,埋藏于地下的古红土由于未被人为利用,受人为干扰小,因压实等影响结构性不良,主要以<0.25 mm微团聚体为主;(2)古红土被利用后土壤团聚体<0.5 mm的减少、> 0.5 mm的增加,利用方式不同,古红土的团聚体(粒级)变化不同(土层深度);(3)团聚体林地以> 5 mm为主,疏林荒草地、荒草地和耕地以> 5 mm、5~2 mm和2~1 mm为主;(4)古红土被开发利用后,土壤团聚体的稳定性增加,且林地的稳定性强于耕地,是古红土分布地区一种较合理的利用方式。  相似文献   

7.
中国水稻土的粘土矿物   总被引:1,自引:0,他引:1  
张效年 《土壤学报》1961,9(Z2):81-102
应用X射线衍射法、差热分析法和化学分析法,鉴定了中国主要水稻土区的近六十个土壤标本。粘粒系小于2微米的部分。水稻土的粘土矿物组成与其母质有密切关系,在一般情况下,它继承了母质的矿物组成。不同母质发育的水稻土的主要粘土矿物组成可见表17。水稻土形成过程中粘土矿物组成的变化可分为三种不同的情况:富有含钾矿物的母质发育成水稻土时脱钾作用明显,粘土矿物有较大的变化。中量含钾矿物的母质发育成水稻土后,粘土矿物组成的变化很小。没有含钾矿物的砖红壤发育的水稻土,在成土过程中有明显的复硅和复盐基作用,在老水稻土中,三水铝石减少,同时出现了濛脱类矿物。水稻土表层与心土层的粘土矿物组成,只有少数土壤有明显差别,大多数看不出差别来。水稻土的潜育层与其上部土层比较起来,除氧化铁含量有显著减少以外,粘土矿物组成基本上是相同的。因此潜育作用的实质主要是部分游离氧化铁的还原,淋失,而粘土矿物并未遭受特别强烈的破坏。根据粘土矿物的异同,暂时将中国水稻土分为四个地理区:以高岭类(三水铝石)为主的华南水稻土区,也就是热带和南亚热带双季稻地区,以高岭类(云泰、濛脱类)为主的华中水稻土区,也就是中亚热带双季稻地区,以濛脱类和云泰(高岭类)为主的长江中、下游水稻土区,也就是北亚热带稻麦两熟地区,以云泰(濛脱类)为主的华北水稻土区。由于水稻土的粘土矿物组成仍受其前身——地带性土壤的影响,因此上述各区的粘土矿物组成,也反映出地带性的特征。  相似文献   

8.
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。  相似文献   

9.
海拔与岩性变异对石灰岩发育土壤黏土矿物组成的影响   总被引:1,自引:0,他引:1  
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。  相似文献   

10.
谢萍若 《土壤学报》1987,24(1):18-26
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.  相似文献   

11.
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.  相似文献   

12.
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   

13.
Hematite is an important iron oxide mineral in loess–paleosol sequences in northwest China. Samples containing hematite and related minerals in the loess and paleosol units from Chinese Loess Plateau were investigated using powder X-ray diffraction (XRD), scanning electron microscopy (SEM), and high resolution transmission microscopy (HRTEM). The results show that there are at least three genetic types of hematite in Quaternary loess–paleosol sequences of northern China: (1) Weathering products of Fe-bearing silicate minerals, such as chlorite and biotite, that precipitated as aggregates of hematite nano-crystals on mineral surfaces; (2) oxidation products of eolian magnetite grains with hematite nano-crystals closely associated with magnetite; (3) coarse (silt-sized) hematite grains present in the fresh loess. Hematite with a nanoporous texture indicates that dehydration of iron hydroxide ferrihydrite is the main mechanism for the formation of hematite coating during chemical weathering of Fe-bearing silicates. It is proposed that nano-phase hematite is primarily responsible for the red color of the paleosol units. Paleosol layers are also characterized by higher magnetic susceptibility and increased oxidation of eolian magnetite. It is proposed that the major contribution to magnetic susceptibility is from the nano-phase magnetite that may be related to microbial activity. This research demonstrates that the study of mineral characteristics, formation mechanisms and the relationship between hematite, other iron oxides, and Fe-bearing silicate minerals helps to understand better the geochemical process in loess, both before and after dust deposition. In addition our study helps to explain the correlation between magnetic susceptibility and paleoclimate in northern China during the Quaternary.  相似文献   

14.
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   

15.
绰墩遗址古今水稻土黏土矿物特征比较研究   总被引:4,自引:2,他引:2  
程月琴  杨林章  曹志洪 《土壤》2011,43(4):617-622
在江苏绰墩山遗址考古发掘中,发现了在剖面不同深度埋藏的距今约6000年的史前水稻土层、距今约3 000年的商周史前的古水稻土层和现代水稻土层.本研究为了比较古今水稻土黏土矿物特征的差异,以土壤剖面P01(包含史前古水稻土、商周史古水稻土和现代水稻土)与P03(仅含商周时期古水稻土和现代水稻土)为对象,测定其各种形态铁锰...  相似文献   

16.
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   

17.
针对西安市金盆水库软弱变质岩边坡的地质条件,在细致分析黏土矿物的主要特性及形成机制的基础上,从微观到宏观的不同尺度,系统研究了黏土矿物对软弱变质岩边坡失稳的影响.结果表明,软弱变质岩成因复杂,矿物成分多样,水稳定性差,易于生成黏土矿物;而次生黏土矿物的形成将引起源矿物、矿物集合体及岩块特性的显著变化,诱发岩石向松散介质转化,并触发黏土矿物在宏观结构面中的聚集和泥化夹层的形成,导致结构面及岩体强度衰减,进而促进边坡变形破坏,对边坡演化及失稳的贡献显著.  相似文献   

18.
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   

19.
Data on the mineralogical composition of clay in soils of solonetzic complexes of the Priobskoe Plateau and the Kulunda and Baraba lowlands have been generalized. The parent materials predominating in these regions have loamy and clayey textures and are characterized by the association of clay minerals represented by dioctahedral and trioctahedral mica–hydromica, chlorite, kaolinite, and a number of irregular interstratifications. They differ in the proportions between the major mineral phases and in the qualitative composition of the minerals. Mica–hydromica and chlorites with a small amount of smectitic phase predominate on the Priobskoe Plateau and in the Kulunda Lowland; in the Baraba Lowland, the portion of mica–smectite interstratifications is higher. An eluvial–illuvial distribution of clay fraction in solonetzes is accompanied by the acid–alkaline destruction and lessivage of clay minerals, including the smectitic phase in the superdispersed state. This results in the strong transformation of the mineralogical composition of the upper (suprasolonetzic) horizons and in the enrichment of the solonetzic horizons with the products of mineral destruction; superdispersed smectite; and undestroyed particles of hydromica, kaolinite, and chlorite from the suprasolonetzic horizons. A significant decrease in the content of smectitic phase in the surface solodic horizons of solonetzic complexes has different consequences in the studied regions. In the soils of the Priobskoe Plateau and Kulunda Lowland with a relatively low content (10–30%) of smectitic phase represented by chlorite–smectite interstratifications, this phase virtually disappears from the soils (there are only rare cases of its preservation). In the soils of the Baraba Lowland developed from the parent materials with the high content (30–50%) of smectitic phase represented by mica–smectite interstratifications, the similar decrease (by 10–20%) in the content of smectitic phase does not result in its complete disappearance. However, the smectitic phase acquires the superdispersed state and the capacity for migration.  相似文献   

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