Parent Material Properties Research Articles

Landform Selection and Soil Modifications Associated with Arctic Fox (Alopex lagopus) Den Sites in Yukon Territory, Canada

Arctic fox (Alopex lagopus) dens were examined in the unglaciated portion of the Yukon Coastal Plain and on Herschel Island. Den site selection relative to landform type was evaluated for 65 dens. On the Yukon Coastal Plain foxes established dens on sandy fluvial and wind-modified (dunes) fluvial deposits almost exclusively. On Herschel Island, moderately eroded landscapes were selected over noneroded, slightly eroded, and wetland terrain. The use of terrain maps proved to be useful in defining suitable den habitat. Chemical and physical properties of soil were compared on and immediately adjacent to 25 dens. Mean values for soil temperature, depth to permafrost, soil particle size, pH, N, and exchangable K were significantly different (P < 0.05) between on-den and off-den samples in both study areas. Total carbon, total phosphorous, and C:N were significantly different on Herschel Island but not on the Yukon Coastal Plain. The role of foxes in modifying soil chemical and physical properties is discussed relative to differences inherited through the parent material properties.

How mudrock and soil physical properties influence badland formation at Vallcebre (Pre-Pyrenees, NE Spain)

Soils, regoliths and their parent materials were investigated in relation to the development of badlands in the Pre-Pyrenees, in NE Spain, on Late Cretaceous mudrocks under a mountain Mediterranean climate. Whilst all the soils in the area which are developed on mudrocks show a good structure and support a dense plant cover, the bare parent materials slake very rapidly giving rise to badlands characterized by high erosion rates. Several physical, chemical, mineralogical and micromorphological properties of soils, regoliths and related parent materials were analyzed in order to explain their different susceptibility to erosion and to determine which of all these properties are better related to such erosive behaviour. Only micromorphological and porosity properties were able to explain the erosion susceptibility, whilst mineralogical, chemical and physico-chemical (specific surface area) properties were not. Among the aggregate stability tests performed to estimate the relationships of soil components with the susceptibility to erosion, the Emerson test for macroaggregate evaluation, was particularly well suited. Although no good correlation was found between the Emerson test classes and organic matter content, we observed that the degree of slaking in organic-rich horizons, was always lower than in subsurface horizons and regoliths. Consequently, as far as organic rich aggregates are present in the soil surface, the influence of water in producing slaking, swelling and then erosion, will be minimum. However, when regoliths and rocks are uncovered, the influence of water in these particular materials, through freeze-drying and swell-shrinking, will give rise to mudrock desintegration leading to accelerated erosion.

Effects of the method of preparation of MgC 2O 4 as a support precursor on the properties of iron/magnesium oxide catalysts

Samples of iron/magnesium oxide catalyst in which magnesium oxalate was used as a common support precursor were prepared alternatively from magnesium nitrate (N) and from magnesium acetate (A) and were tested in hydrocarbon synthesis. Sample N showed the higher activity by one order of magnitude while sample A showed better initial selectivity towards alkenes and a slower initial deactivation. BET, X-ray diffraction (XRD), scanning electron microscopy (SEM), Auger electron spectroscopy (AES) and Mössbauer spectroscopy analysis revealed different methods for the formation of the catalyst in all the stages of preparation. Lower activity of sample A was explained by hindered reducibility of the iron component, due to the fact that support effects were affected by individual properties of the support precursor parent materials, as well as by the preparation conditions which they imposed.

火山灰土壌の腐植特性の空間分布の推移にみる環境変化 赤城火山南麓における事例

By a series of studies to clarify the humus characteristics of volcanic ash soils and soil forming environment, the influence of climate variation was recognized in the eastern foot area of Nantai Volcano, Nikko (Watanabe 1985, 1987). The purpose of this study is to obtain useful information for the reconstruction of global scaled environmental changes from spatial distribution of soil humus characteristics. Volcanic ash soils developed in the southern foot area of Akagi Volcano were examined as a case.The result is summarized as follows.1. Soils developed over southern foot area of Akagi Volcano show several types of soil profiles regulated by the thickness and rate of tephra deposits and geomorphic surfaces. On mountain slopes formed by pyroclastic flow, brownish volcanic ash bed are to be seen between surface and buried humus layer. Soils distributed on central cone lacustrine surface have thick and dark humus layer called “gleyed Kuroboku”. Soils with light humus layer develop on piedmont surface under the influence of artificial activity. The brownish volcanic ash bed mentioned above is difficult to distinguish from this layer.2. The chronological sequence of soil formation in the study area was considered on the basis of properties of soil parent materials and radiocarbon dates. Horizon I is the layer which continues to accept humus supply and humification under soil forming environment in the present. Fresh volcanic ash errupted from Asama and Haruna Volcano, about 200-1700 years ago are included in this layer. Horizon II correspondent to the brownish volcanic ash bed has accepted humus substances from the upper layer. Though the source volcano is unknown, this layer is assumed to be deposited about 4, 000 years ago. Horizon III, a buried humus layer intercepted from surface environment, started soil formation about 9, 000 years ago following to the erruption of Asama Itahana Yellowish Pumice (YP).3. The vertical distribution of humus characteristics (brightness of soil color, carbon content and humus composition) was classified into two types, which reflects the conditions of vegetation and groundwater level regulated by gemorphic surface.4. The spatial distribution patterns of humus characteristics such as carbon content and RF value of humic acid in each horizon show vertical zonality. The principal areas of humus accumulation in the age of horizon II and III formation were located in higher location than present, about 400m upward. Humic acid classified such as type A+, P+ +, have remarkable absorption spectra near 615, 570, 455nm which are regarded to be the features of soils formed under vegetations such as Fagus, Quercus mongolica and also under cool and wet condition in the study area. The appearance of these humic acid types in each horizon also tend to move its location upward by 300m in the age of horizon III formation.

The soils of the Kalahari Gemsbok National Park

Field observations made during a reconnaissance soil survey of the Kalahari Gemsbok National Park showed that a variety of soils occur within the broad group of so-called Kalahari sands. For discussion purposes, the soils were classified into five main groups of which the red and yellow sands took precedence over the other soils because of their geographical distribution and pedological significance. The soils are discussed with special reference to their classification, site and parent material, their morphological, chemical and mineralogical properties and drainage characteristics. Attention was also given to the relationship between the soils and landforms, and a brief note on the inherent fertility status of the soils has been included.

Comparative micromorphology of soddy-podzolic soils derived from loamy moraine and non-calcareous loesslike loam

Soddy-podzolic soils developed on different loamy parent materials possess several common fabric features which can be regarded as characteristic of this soil type. These features are: poor aggregation, considerable amounts of coarse plant residues in different (mainly weak and medium) stages of decomposition, predominance of brown-coloured peptized humus mainly bound up with sesquioxides, abundant clayey and silty illuviation cutans appearing in the A 2 or A 2 horizons where they show the strongest disruption and incorporation into the s-matrix, and different forms of biological segregations of iron and manganese hydroxides. Some differences in fabric of these soils are connected with mineralogical and physical properties of parent material.

Soils of some Quaternary marine terraces in the British Solomon Islands Protectorate and some problems in their agricultural use

Abstract The Quaternary marine terraces discussed are formed predominantly from coral, but the soils overlying them are strongly influenced by subsequent volcanic deposits. Six “land systems” are defined and morphological, chemical, and physical properties of their main soils are detailed. The mineralogical properties of soils and parent materials indicate varied stages of weathering, and these are reflected in plant nutrient levels. Agronomically the most important feature common to all the soils is the extremely low level of subsoil potassium. Some of the soils also require sulphur, and possibly manganese, for coconuts. With shifting cultivation, incoi porating long fallows, food cropping can be sustained, but if cultivation is prolonged, potassium fertilising is essential for optimum growth.

Genetic Studies on the soil in Hokkaido (Part 3) : The Effects of the Properties of Parent Materials on the Types of Soil Formation.

Genetic Studies on the soil in Hokkaido (Part 3) : The Effects of the Properties of Parent Materials on the Types of Soil Formation.