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1.
The author, head of the Department of Soil Science and Landscape Geochemistry at Moscow University's Geography Faculty, notes that the traditional zonal concept based on heat belts of the earth no longer accounts satisfactorily for the world distribution of soils. She proposes a typology of geographic soil units based on soil characteristics rather than soil-formation factors: major geochemical fields based on soil reaction and oxidation-reduction potential; and soil sectors within fields, defined in terms of soil classes and families, the history of soil formation, and the energy level of soil processes.  相似文献   

2.
By analogy with soil catenas, which are groups of related soils differing from one another as a result of variation in relief and drainage, the author suggests the existence of geochemical soil catenas, in which the lateral migration of chemical elements links the related soils of uplands, slopes, and depressions into a geochemical entity. On the basis of the conditions of migration, soils are divided into geochemically autonomous, eluvial soils on uplands and geochemically subordinate soils on slopes (transaccumulative situations) and in depressions (superaqueous situations). In humid regions, geochemical soil catenas are distinguished mainly on the basis of the mobility of iron and aluminum compounds; in arid regions, mostly in terms of the mobility of the sulfates and chlorides of sodium and calcium. Geochemical soil catenas in the periglacial situations of the Antarctic and the Tien Shan and in the humid subarctic situation of northern Scandinavia were investigated in the field. The field data and the available literature are used to construct a typology of the world's principal geochemical soil catenas and their determinant factors.  相似文献   

3.
The soil formation in a number of pits on a neolithic excavation was compared with that in adjacent loess soils (Hapludalfs) under forest and arable and in Bavaria, Southern Germany. The differences between the soils under consideration were mainly characterized by micromorphological quantification of the illuviated fine clay. In the archaeological pits the amount of illuviated fine clay proved to be nearly twice as much as that in the undisturbed soils. The amount of illuviated coarser matrix components (fine and coarse clay and fine silt) in the neolithic pits did not differ significantly from that in the natural soils. The large amount of illuviated fine clay in the pits was ascribed to the presence of potash during the period of their formation. The formation of coarse grained illuviation cutans was related to deforestation, after which illuviation of the fine clay decreased in intensity and came to a stop.  相似文献   

4.
The soluble and exchangeable ions for a soil profile from the Roonka archaeological site. Lower Murray Basin, South Australia, are compared with the total elemental content of the soils. Since the chemical composition of post-mortem ionic substitution phases and secondary minerals in archaeological bone will depend on the availability of ions to the soil solution under field conditions, it is suggested that models addressing diagenesis in bone employ soluble and exchangeable ions rather than total elemental soil data.  相似文献   

5.
Marx’s writings on Ireland are widely known, but less appreciated is their centrality to the formation of his ecological thought. We show how Marx’s understanding of metabolic rift evolved in line with his writings on colonial Ireland, revealing a concept more holistic than the “classic” metabolic rift of the soil. We recover and extend this concept to the corporeal metabolic rift, showing how both are inherent in Marx’s various writings on Ireland. Whilst the rift of the soil concerns the extraction and consumption of organic soil constituents, the corporeal rift describes processes of depopulation, and their effects on demography and family formation. These “rifted” processes are interconnected such that depleted soil impacts on the health of those who consume food grown on those “rifted” soils. We argue that the presence of these rifts substantiates Ireland’s inability to sustain itself both economically and organically, which determined its persistent post-Famine underdevelopment.  相似文献   

6.
7.
Prolonged stability of the southern tableland of NSW, developed on early Tertiary Monaro basalt, is evident from weak landscape dissection and numerous small lakes. However, poorly developed soils and weathered zones are inconsistent with prolonged Cainozoic weathering or formation under climates substantially different to the present. Thin Holocene sediments are also at variance with the sizes of the lake basins. Low depositional landforms, termed ‘lake shadows’, occur on the eastern perimeters of most lakes, and comprise clay pellets blown from basin floors during dry phases. Deflation, dominantly during Quaternary glacial periods, and reactivated today, is responsible for the thin soils and sediment cover. The lake basins are partly solutional and partly deflational features. The modern soil cover reflects the modern climate.  相似文献   

8.
Falling trees commonly turbate soils in primary forest, creating characteristic edaphic patterns related to pit and mound topography. Vernal ponds with associated mounds were observed in mineral soils on a treeless plain in subalpine Tasmania, Australia. The hypothesis that paired ponds and mounds on the plain originated as pit and mound features in forests that were later destroyed by fire was tested by comparing the soils and landforms caused by recent tree falls in adjacent forest with those on the plain. The soil characteristics, orientations, and dimensions of the ponds and mounds were consistent with a tree fall origin, although rare secondary ponds on the tops of mounds may derive from the burrowing activities of the medium‐sized marsupial, Vombatus ursinus (common wombat). The characteristics of pond and mound soils suggested that most were hundreds to thousands of years old, with the ponds persisting because of differences in deflation, deposition, and organic matter formation between themselves and adjacent persistently dry land.  相似文献   

9.
The author analyzes the landscape-forming role of the snow cover by distinguishing four snow-cover periods in the winter season and investigating snow-accumulation conditions under various meteorological, relief and vegetation situations. The effect of the snow cover on ground frost, the wintering of plants and animals, the amount of surface runoff and soil erosion in the spring is analyzed for various combinations of conditions in each period.  相似文献   

10.
It is well known that local soil conditions play a key role in the amplification of earthquake waves. In particular, a liquefiable shallow soil layer may produce a significant influence on ground motion during strong earthquakes. In this paper, the response of a liquefiable site during the 1995 Kobe earthquake is studied using vertical array records, with particular attention on the effects of nonlinear soil behaviour and liquefaction on the ground motion. Variations of the characteristics of the recorded ground motions are analysed using the spectral ratio technique, and the nonlinearity occurring in the shallow liquefied layer during earthquake is identified. A fully coupled, inelastic finite element analysis of the response of the array site is performed. The calculated stress-strain histories of soils and excess pore water pressures at different depths are presented, and their relations to the characteristics of the ground motions are addressed.  相似文献   

11.
Acid sulphate soils form when iron pyrite oxidises to sulphuric acid on atmospheric exposure, lowering soil pH below 4. In the Richmond River estuary, northern New South Wales, flood mitigation, drainage works and floodplain excavations have augmented acid sulphate soil formation by increasing pyrite availability for oxidation. These engineering works have facilitated the transport of acidified water and have impeded recovery from tributary acidification. The increased frequency and duration of acidification are associated with elevated concentrations of inorganic monomeric aluminium and dissolved iron, and major iron hydroxide precipitation, with deleterious effects on exposed aquatic biota and habitat. Fish kills and an outbreak of epizootic ulcerative syndrome (EUS) have been recorded from acidified sites in the estuary.  相似文献   

12.
In this study we present the results of a combination of methods used to identify possible agricultural activity of the ancient Maya in the Usumacinta River Basin in Guatemala. These methods included stable carbon isotope analysis of bulk soil organic matter, soil profile investigations and a spatial model of gentle slopes and well-drained soils to identify favorable agricultural conditions. Stable carbon isotope analysis of bulk soil organic matter in particular offers potentially direct evidence of agricultural activity. The δ13C results suggest that there is a strong signature of C4 plants, such as maize and tropical grasses, throughout the study area. Further, the current soil conditions and extent of relatively gently sloped areas are favorable to agriculture. Overall, the results are supportive of the hypothesis that the area, located between the polities of Piedras Negras and Yaxchilán, was agriculturally important to surrounding areas.  相似文献   

13.
西安地区全新世土壤的演变   总被引:1,自引:0,他引:1  
野外调查和室内实验资料表明 ,西安临潼全新世发育了 4层土壤。其中有两层发育在较温湿的气候条件下 ,两层发育在较冷干的气候条件下。温湿条件下发育的土壤为棕色土与淋溶褐土 ,冷干条件下发育的土壤为典型褐土与粘化黑垆土。临潼与长安全新世土壤结构及粒度成分指示 ,自全新世中期的大暖期以来 ,西安地区气候环境呈明显的变干趋势。  相似文献   

14.
The paper surveys the present state of the study of the moisture and heat factors of soil formation under the geographic, genetic and agronomic approaches of soil science. The author finds that despite the single physical nature of the phenomena to be studied they have been investigated separately within the framework of each of these approaches. He calls for an integrated study of the moisture and heat factors by the soil-science field as a whole and outlines specific steps.  相似文献   

15.
Current soils can have attributes inherited from land management systems in the past or previous environmental conditions. An important archaeological question is the extent to which the record of old agricultural practices can be retained in soils. This paper reports the results from examining soil thin sections collected from a range of old cultivated sites in the upper Bowmont valley, south east Scotland. The cultivated horizon was sampled from rigs and cultivation terraces dating from prehistoric to late medieval times. The main finding from microscopic analysis was the considerable impact of bioturbation as expressed in excremental pedofeatures. Results from point counting of these pedofeatures from 10 slides collected from an experimental site at Sourhope provided quantitative evidence on the extent to which bioturbation had occurred over the last 200 years. The rapidity by which micromorphological indicators of previous cultivation can be lost is thus demonstrated.  相似文献   

16.
Many attributes of present day soils can only be explained by reference to land management in the historic past. This is particularly well expressed in the plaggen soils which occur extensively on the north European plain. These deepened soils owe their dominant characteristics to the application from the 12th century of turf materials, often impregnated with dung. Similar deepening of soils can result from the disposal of urban waste. This paper discusses the results of soil research focused on a small Scottish town (Nairn). A soil survey revealed topsoils of over 1 m overlying fluvioglacial sands and gravels; such deepening is explained by the use of town waste on the burgh's arable lands from at least the 17th century up until the mid-19th century when an integrated sewerage system was installed. Micromorphological study of this deepened topsoil revealed the presence of many small black carbonaceous particles. Oxygen:carbon ratios were calculated from microprobe results as a means of confirming the carbonaceous nature of these particles. Soil phosphorus was primarily concentrated on the perimeter of these particles. The high quality of present day soils on the edge of the town is explained by the disposal of waste material, which included much carbonised material. This paper is the first to highlight the importance and potential of examining the gradation in soils from urban to rural contexts.  相似文献   

17.
The objective of this paper is to assess the relationship between the cereals cultivated in the Late Bronze and Early Iron Ages (ca. 1250–400 BC) within the area of the present-day Czech Republic, and their environmental settings. The various charred caryopses of cereal species represented in the archaeobotanical assemblages from 35 archaeological sites differ, especially in the proportion of wheat and barley. The cereal assemblages were compared regarding site altitude, weather conditions, soils and soil productivity. The most important environmental variable influencing the choice of a particular crop seemed to be altitude which is correlated with other variables such as the length of growing season, mean annual temperature, soil quality etc. Although the ecological requirements of cereals cultivated in the Late Bronze and Early Iron Ages are not known, they presumably thrived under similar conditions to present-day species/varieties, and the strategy of past crop husbandry was based on similar principles as today, e.g. flexible adaptation to local environmental conditions, in an effort to achieve optimal yields and reduce the danger of crop failure.  相似文献   

18.
Pedology is a discipline with a wide range of applications in geology, geomorphology, archaeology, geoarchaeology and geography. Especially paleopedology aims are to answer questions about climatic changes, rates of pedogenic processes, pedostratigraphy, suitability of former surface soils and human occupation. In combination to other disciplines, pedology aims to advance geoscientific methods at different scales, and during the last decades, (paleo)pedological research increasingly touched archaeological fields whereby soil research was mostly somehow included in geoarchaeology. When the term ‘archaeopedology’ was introduced in the 1940s, researchers were already aware of the importance of the subject ‘soil’ as being a key figure when answering questions of site formation history, cultural chronology and environmental change. The present paper aims to reintroduce this term to the scientific community and to accentuate the importance of buried soils within geoarchaeological research. Shown by two different studies, one from Upper Palaeolithic sites in the Ueckermünder Heide/Germany and one from ancient Yeha/Ethiopia the archaeopedological approach highlights the importance of pedological research on- and off-site excavations by clearly bridging a gap between archaeology, geoarchaeology and (paleo)pedology.  相似文献   

19.
Chemical and mineralogical analyses of samples from a 102 m deep borehole and from road cuts on the summit surface of the Mount Lofty Ranges near Willunga Hill, are used to assess critically the view that the regolith here developed as a result of tropical, so‐called ‘lateritic’ weathering processes that developed a standard ‘laterite’ profile of great antiquity. There is no evidence of a former surface crust that comprises the upper part of a ‘standard laterite profile’. Moreover, there is no dramatic variation in chemical composition down the profile, with largely in situ localised weathering transformations explaining mineralogical variability. The presence of 2:1 layer silicates and the absence of gibbsite do not favour the operation of former intense tropical weathering, but the possible presence of chloritised smectite may have inhibited gibbsite formation. An iron‐depleted pallid zone does not occur at depth in the profile, but is present on the plateau margin. Many of the weathering features exposed in the road cuts can be explained in terms of modifications and developments under environmental conditions similar to those of the present, arguing against the view that the summit surface and its associated weathering mantle have been preserved in pristine form since the Mesozoic.  相似文献   

20.
The soil which has developed at any given location is considered to be the result of five interacting factors: parent material, time, climate, topography and biotic factors. This paper discusses the role of these factors in the development of Scottish soils, which fall into three broad categories: leached soils, gley soils and organic soils. The intention is to provide a context for the case studies that follow in later papers.  相似文献   

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