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1.
残积母质是青海湖地区重要的成土母质之一,目前对高原残积母质土壤的研究相对匮乏,特别是其形成发育的年代尚不明晰,限制了对高原残积母质土壤演变过程的认识及对区域气候环境演变的理解。为探究青藏高原东北部残积母质土壤的发育过程及其发育模式,以青海湖北部宁夏（NX）剖面作为研究对象,通过光释光（Optically stimulated luminescence,OSL）测年获得残积母质土壤发育年代,采用化学蚀变指数（Chemical index of alteration,CIA）、Rb/Sr和粉黏比等探究土壤发育程度,对比青海湖地区河湖相沉积和黄土的Zr/Nb、K2O/Al2O3和TiO2/Al2O3分析其物源。结果表明：NX土壤剖面在早全新世以来发育,其年代结果集中在10.02~8.67 ka,成土母质发育时间与流域内风沙强烈活动时期基本一致,为干暖气候背景下的产物;通过物源对比分析,NX剖面底部母质为母岩就地风化而成,上部为风尘加积发育,发育模式为混合母质风尘加积型;剖面整体处于弱化学风化阶段,土壤发育程度较弱。 相似文献
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陕西渭北旱塬典型苹果园土壤基本性质与微形态特征研究 总被引：1，自引：0，他引：1
通过对土壤微形态研究试图阐明陕西渭北旱塬长龄苹果园土壤的发育过程和质量演变。用偏光显微镜对LAS剖面不同发生层的薄片进行了观察和影像定量分析。结果表明:土壤形成物主要是粘土矿物、方解石和无定形Fe,Ap层中有大量次生方解石、次生粘土和蚯蚓粪粒,AB层与BC层方解石数量多且形态最复杂,黏土含量高,BC层可见大量淀积黏土,Ck/C层细晶与针状方解石较少,有少量残积粘土;土壤孔隙主要是孔道和填充孔隙。整个剖面从上向下微结构连续变化,反映了苹果地较稳定的土壤环境,也可能与人工苹果园长时间种植有关;不同发生层的矿物组合十分相似,石英(Q)和长石(Pl)占绝对优势,但C/F10μm值、不同矿物间的比例、颗粒形态等有明显差异。 相似文献
3.
安徽南部盆地紫色岩系上土壤的发生特性 总被引：3，自引：1，他引：2
在安徽南部采集不同地质年代、不同层位紫色沉积岩发育的6个土壤剖面,研究其发生特性和成土特点。结果显示,紫色沉积岩发育的土壤,在一定程度上继承了母岩的特点,化学风化作用微弱。大多数土壤的粉粒/粘粒比值都在1.3以上,土壤B层粘粒硅铝率均大于3.7,游离铁含量(16~29)g/kg,土壤发育程度明显低于同地区的花岗岩风化物发育的湿润淋溶土。大多数土壤盐基饱和度>50%,2个土壤剖面盐基饱和度<30%,而且铝饱和度较高为60%~90%。 相似文献
4.
本文通过对土壤剖面中的矿物质成分分析,计算出了各土类间元素含量的变异系数。结果表明,各土类的烧失量、CaO的高变异,烧失量、CaO和MgO三者的相对比例,硅铝铁分子比率及风化淋溶系数等,反映了该区土壤形成特点及发育程度。 相似文献
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根据不同母质发育的土壤，采集了水稻土耕层样８６个，旱地耕层样４３个。土壤剖面样１７个，有效硅测定方法，用ｐＨ＝４的１ｍｏｌ／ＬＮａＯＡＣ－ＨＡＣ为提取剂，加显色剂后，用分光光度计测定含量，有效硅总的趋势是酸性岩及其变质岩发育的土壤低于沉积岩的含量；第四纪沉积物中，Ｑ４低于Ｑ２时期的含量。在相同气候条件下，成土母南和粘粒含量是影响有效硅含量的主要因素。 相似文献
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湘东丘陵区4种林地深层土壤溶解性有机碳的数量和光谱特征 总被引：3，自引：0，他引：3
选取湘东丘陵4种典型母质发育的林地土壤,挖掘土壤剖面并分层采集土壤样品至母质层/母岩,研究深层土壤有机碳（SOC）和溶解性有机碳（DOC）的数量和分布规律,采用紫外-可见光谱技术分析深层土壤DOC的宏观化学结构特征。结果表明,土壤DOC含量（2.33~185.26 mg·kg^-1）在板岩红壤和酸性紫色土剖面上某些深层土层出现升高现象。DOC/SOC除第四纪红土红壤在浅层表土最高（1.5%）外,其他3种土壤均在60~80 cm深层土层达到最高峰值（1.0%~2.5%）。SOC数量是控制不同母质土壤DOC数量的重要因素。但光谱分析显示,随着土壤剖面的加深,DOC的宏观化学组成、结构趋于复杂,化学稳定性升高。尽管一些深层土层中DOC/SOC升高,但其DOC化学结构更为复杂,评价深层土壤SOC和DOC稳定性还应考虑其化学结构特性。 相似文献
9.
红壤丘陵小区域水平上不同时段土壤质量变化的评价和分析 总被引：39，自引：1，他引：39
引相相对土壤质量指数的概念，应用地理信息系统技术，为小区域水平上土壤质量时空变化的评价提供了一种方法，并用于千烟洲试验站开垦利用１１ａ后土壤质量变化的评价。统计分析服农田，桔园，牧草地，人工林，天然林等多种土地利用方式下土壤质量变化的特征。 相似文献
10.
本文比较研究了３种植被类型－光裸地，桉林与混交林对土壤的影响，结果表明，植物体内养分的含量相对独立于土壤中的养分供应，而主要是由植物自身的生理特性决定的。从长远看，它将导致土壤中某些元素的相对积累或其有效态含量的提高，长期的淋溶没有完全使土壤丧失生长植物的矿质养分基础，植被恢复对土壤矿质全量没有显著影响；不同类型的植被对土壤的改良一肥力发育有不同的影响。 相似文献
11.
《Geomorphology》2007,83(1-2):14-28
The southern part of the Pakua tableland in Taiwan comprises a series of wide, unpaired river terraces that have as many as six altitude levels, from PK-1 (highest) to PK-6 (lowest). The terrace surfaces are covered with lateritic soils. This study described, sampled and analyzed the soils from each terrace. Soil taxonomies are Oxisol, Ultisol and Inceptisol. Soil morphological characteristics were quantified as a profile development index (PDI) to determine the degree of soil development. The chemical analyses included cation exchange capacity (CEC) and selected extraction of Fe in soils. Based on the degree of soil development, surface deposits on terrace flights form the post-incisive soil chronosequence, supporting the hypothesis of terrace formation by fluvial processes. Soil ages were estimated based on iron crystallinity (Fed–Feo)/Fet. Analytical results indicate that river terraces in the Pakua tableland are aged 40–400 ka. The long-term uplift rate of the tableland can be estimated using terrace ages and folding geometry. The variation of uplift rates demonstrates that the landscape underwent increased shortening of frontal thrusting by the Changhua Fault running beneath the tableland. 相似文献
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A numerical index of soil development, the POD Index, was developed and applied to 723 pedons of United States soils that either exhibit, or are developing, Podzol (Spodosol) morphology. The index is determined solely from morphologic (field) criteria, and provides the first soil development index for Podzol and Podzol-like soils that does not use chemical data. The index assumes that pedogenesis and profile development in these soils produces the following morphologic changes; (1) the E (eluvial) horizon becomes “whiter,” (2) the B (illuvial) horizon becomes “redder” and “darker,” and (3) the number of B subhorizons increases. Results indicated that the index was useful for differentiating between non-Podzols and Podzols, and between Entic and Typic subgroups of Spodosols. A comparison of POD Indices for Spodosols of differing drainage revealed that maximum development occurred in wet soils (somewhat poorly drained), with minimal development on the driest sites. This finding is consistent with current theory on the effects of drainage/water table relations on Podzol development. Additionally, the index has usefulness in chrono-sequences of Podzol soil development [Key words: soils, Podzol, Spodosol.] 相似文献
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Eric T. Karlstrom 《自然地理学》2013,34(4):301-327
A chronosequence of 17 soils in late Quaternary alluvium on Black Mesa, northeast Arizona, permits quantification of rates of pedogenesis in a semi-arid region. Based on 24 tree-ring, radiocarbon, and archaeological dates, soil ages range from about 100 to 20,000 to 30,000+ years. Data indicate that ochric, cambic, argillic, natric, and calcic horizons form within about 100, 500, 1000, 3000, and 15,000 years, respectively, whereas mollic epipedons form within 1000 years. Bk horizons with Stage I, I+, II+, and III carbonate morphologies form within about 1000, 4000, 10,000, and 15,000 years, respectively. Thickness of Bt and Bk horizons, and Harden profile development and clay accumulation index values increase in a linear manner with increasing soil age. High resolution dating suggests rates of pedogenesis on Black Mesa are rapid relative to those documented elsewhere in the southwest United States and in the Rocky Mountains. Rates of soil formation recorded on Black Mesa, however, necessarily incorporate the combined effects of slight variations in elevation, climate, vegetation, topography, and parent materials throughout the region, as well as the influence of additions of atmospheric dust at the soil surface. [Key words: soil, pedogenesis, soil geomorphology, Quaternary, Arizona.] 相似文献
15.
首次对格罗夫山地区漂砾的暴露年龄进行的研究表明,萨哈罗夫岭冰原岛峰的两块漂砾样品的 Be最小暴露年龄分别为1．24±0．11Ma和1．37±0．12Ma, 。A1最小暴露年龄分别为0．90 4-0．12Ma和0．44±0．04Ma。萨哈罗夫岭附近冰面上的漂砾样品的 Be和 A1最小暴露年龄分别是0．47±0．3Ma和0．44±0．04Ma。考虑到误差,萨哈罗夫岭三块漂砾的最小暴露年龄与相近高程的基岩样品的最小暴露年龄基本一致。因此,在利用原地生成宇宙成因核素测年技术对东南极内陆格罗夫山地区的冰川消涨历史进行研究时,基岩和漂砾暴露年龄所反映出的冰川演化历史是明显吻合的。 相似文献
16.
To understand whether soils on the same geomorphic surface have similar properties, this study examines the morphology of soils developed on the 30-kyr-old Taoyuan Terrace, Northwestern Taiwan. Relationships among soil morphology, variations in the groundwater table, and soil forming processes were established based on field investigations and previously published datasets. The soil series in the study area can be grouped into seven types, including three homogeneous groups, two mottled groups, one gley group, and one reworked group. Fifteen hand-core samples collected in the field and borehole data were used to understand spatial variations in soil morphology. The results indicate that soil morphology on the southern Taoyuan Terrace changes systematically from the fore-edge to the back-edge: from red/orange soils to yellow soils, then to mottled soils, and finally to gley soils. The borehole data indicate that the groundwater table is generally parallel to the ground surface but drops significantly near the terrace fore-edge. This pattern matches with the observed soil toposequence, indicating that the pedogenic processes in the study area are mainly controlled by groundwater distribution determined by topography. Although soils on the terrace fore-edge have developed under the well-drained conditions that favor lateritization, at least two distinct soil types (i.e., red and orange) can be observed there, reflecting different geomorphological settings in a paleo-fluvial landscape. This work suggests that geomorphological and hydrological conditions should be examined carefully before using soil morphology for correlating geomorphic surfaces. 相似文献
17.
A Soil Chronosequence from Neoglacial Moraines in Western Norway 总被引：1，自引：0，他引：1
David J.A. Evans 《Geografiska Annaler: Series A, Physical Geography》1999,81(1):47-62
A soil chronosequence is presented based upon podzols developed on Holocene moraine crests in the Jardalen cirque complex, western Norway. Simple and inexpensive field and laboratory tests provide information on soil depth development, pH changes, silt/clay translocation and B-horizon reddening and thickness with age. Chronological control on historical moraine ages is provided by lichenometric dates, which support a 5 cm/100 year soil development rate for the first 700 years of pedogenesis. This initial rapid depth development tails off to a maximum rate of 0.06 cm/100 years between c . 1.5 ka and 10 ka BP based upon a Preboreal/Younger Dryas age for the oldest moraines and associated soils in the Jardalen cirque. 相似文献
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庐山JL红土剖面的色度气候意义 总被引：10，自引：0，他引：10
庐山JL红土剖面的Munsell色度体系研究表明,红土色调、明度、彩度等特征值沿剖面呈有规律变化,随深度增加,红度加深、明度降低、彩度增高,总体呈现7次高低值相间的波动。红化率RR作为衡量红化程度的综合指标,随深度增加波动式递增,亦存在7次旋回,与土体中Fe2O3含量的变化趋势一致。该结论表明,庐山红土发育过程中存在热中见凉的气候波动,第四纪以来气候渐趋干凉。同时,RR曲线与C IA曲线变化趋势一致,RR高值对应于CIA高值,指示强成土风化时期,可作为反映成土环境变化的代用指标。 相似文献
19.
The soil properties of a vegetation chronosequence in Hong Kong involving a grassland, a 22-year mixed woodland, a 52-year forest and two graduation 150-year old climax ( feng shui ) forests were examined. The objectives were to test the three hypotheses: (1) there are no significant differences in soil chemical properties between different climax forests, (2) exotic species are inferior to native species in soil amelioration; and (3) organic carbon, nitrogen and cation nutrients tend to accumulate in the soils during successional development of the vegetation. The results show that the soils along the vegetation chronosequence are strongly acidic in reaction, contained moderate to high levels of organic carbon, high exchangeable acidity, and low levels of mineral nitrogen (NH⊂4⊂> and NO⊂3⊂), available phosphorus and cation nutrients. All the three hypotheses are rejected. While the feng shui forests differed markedly in soil properties, exotic species were superior to native species in augmenting soil organic carbon, mineral nitrogen and exchangeable Ca. There was no accumulation of organic carbon, nitrogen and cation nutrients with ecological succession, due to the influence of patchy fire, species composition, parent materials and distance from the sea. 相似文献
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Late Glacial and Neoglacial (Little Ice Age) deposits on the Humboldt Massif were analyzed for relative-age dating parameters, including geomorphic and weathering characteristics, geochemical and soil properties. The soil chronosequence, formed in chemically uniform parent materials, provides an important database to study soil evolution in a tropical alpine environment. Extractable and total Fe and Al concentrations, examined to assess their use in relative-age determination, and as paleoenvironmental indicators, provide an important measure of the accumulation and downward profile movement over time of organically-bound Al, ferrihydrite and other crystalline forms (hematite and goethite) of extractable Fe. Ferrihydrite is particularly useful in determining former perched water levels in soils with relation to paleoclimate. The ratios of most Fe extracts are time dependent. The Fed/Fet ratio, within statistical limits, shows a slow increase from LIA (Little Ice Age) to Late Glacial soils, which closely correlates with other alpine soil studies in the middle latitudes and other tropical alpine locales. Values of Ald (dithionite) and Alo (oxalate extractable) generally do not correlate with time; however, Alp (pyrophosphate extractable) measured against Alt (total) provides insight on the downward translocation over time of organically-bound Al. Low leaching rates in this chronosequence are further supported by clay mineralogy trends and the geochemical data. 相似文献