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Holocene lake-level fluctuations in Lake Bysjön are reconstructed from recorded changes in the sediment limit and the content of reworked minerogenic matter in the sediment. These recorded changes are related to past lake-level fluctuations by correlation to fluctuations convincingly demonstrated in earlier studies. A correlation of regionally significant fluctuations in South Sweden is presented, and the climatic interpretation is discussed. A distinct lowering in lake level culminated at about 9,500-9,200 B.P., recording a major period of drier climate in the earlier part of the Holocene. After a succeeding period of increased humidity, recorded by rising and relatively higher lake level, another major period of increased dryness began at about 6,800-6,500 B.P. In contrast to the older period, the climate was not uniformly drier, but anumber of demonstrated lake-level fluctuations suggest a fluctuating climate. From the reconstruction in Bysjön, dryness culminated at about 4,900-4,600 B.P., and the major period lasted until about 2,900-2,600 B.P. After a succeeding rise in lake level, another distinct lowering is recorded some time between 1,800 B.P. and 1,200 B.P.  相似文献   

3.
Data on the highest level of the Baltic Ice Lake in south-eastern Sweden have been compiled from various modern investigations and a survey map has been drawn on the basis of the new topographical maps. The level regularly rises from c. 40 m a.s.l. in eastern Skåne to c. 1SS m a.s.l. in northern Östergötland, immediately before the final drainage of the Baltic Ice Lake at the Billingen Hill. The gradients of the oldest synchronous shorelines suggest that the outlet of the Ice Lake was situated all the time in the south, on Öresund, or south of the Danish islands.  相似文献   

4.
The dominance of “ecosystem services” as a guiding concept for environmental management – where it appears as a neutral, obvious, taken-for-granted concept – hides the fact that there are choices implicit in its framing and in its application. In other words, it is a highly political concept, and its utility depends on the arena in which it is used and what it is used for. Following a political ecology framework, and based on a literature review, bibliometric analyses, and brief examples from two tropical rainforest countries, this review investigates four moments in the construction and application of the ecosystem services idea: socio-historical (the emergence of the discourse), ontological (what knowledge does the concept allow?), scientific (difficulties in its practical application), and political (who wins, who loses?). We show how the concept is a boundary object with widespread appeal, trace the discursive and institutional context within which it gained traction, and argue that choices of scale, definition, and method in measuring ecosystem services frustrate its straightforward application. As a result, it is used in diverse ways by different interests to justify different kinds of interventions that at times might be totally opposed. In Madagascar, the ecosystem services idea is mainly used to justify forest conservation in ways open to critique for its neoliberalization of nature or disempowerment of communities. In contrast, in the Brazilian Amazon, the discourse of ecosystem services has served the agendas of traditional populations and family farm lobbies. Ecosystem services, as an idea and tool, are mobilized by diverse actors in real-life situations that lead to complex, regionally particular and fundamentally political outcomes.  相似文献   

5.
The REVEALS model was developed to reconstruct quantitatively regional vegetation abundance (in a 104–105 km2 area) from pollen assemblages in large lakes (≥100–500 ha). This model corrects for biases in pollen percentages caused by inter‐taxonomic differences in pollen productivity and dispersal. This paper presents the first case study to validate REVEALS, using empirical data from southern Sweden. Percentage cover of modern regional vegetation in Skåne and Småland, two contrasting vegetation regions, was predicted with REVEALS for 26 key taxa, using pollen assemblages from surface sediments in 10 large lakes, and compared to the actual vegetation within 104 km2 compiled from satellite data, forestry inventories, crop statistics, aerial photographs, and vegetation inventories. REVEALS works well in predicting the percentage cover of large vegetation units such as total trees (wooded land), total herbs (open land), total conifers and total broad‐leaved trees, and it provides reasonable estimates for individual taxa, including Pinus, Picea, Betula, Corylus, Alnus, Tilia, Salix spp., Juniperus, Poaceae, Cyperaceae, Cerealia and Secale. The results show great potential for REVEALS applications, including (1) quantitative reconstructions of past regional land cover important for palaeoclimatology and nature conservation, and (2) local‐scale reconstruction of vegetation (<1 km2 up to ~ 5 km2 area) relevant for palaeoecology and archaeology. Copyright © 2007 John Wiley & Sons, Ltd.  相似文献   

6.
We present the first geochemically confirmed finding of the Laacher See Tephra (LST) on the Swedish mainland, now the northernmost extension of the LST. Sediments were sampled at the Körslättamossen fen, southernmost Sweden, and a high‐concentration cryptotephra occurrence (>65 000 shards cm?3) of the LST was found in a sequence of calcareous gyttja. Tephra identification was confirmed by geochemical analysis using field‐emission electron probe microanalysis and through comparison of the results with published LST data from proximal sites and distal sites north‐east of Laacher See. The LST has previously been divided into eruption phases suggested to have spread in several dispersal fans, but it was not possible to confidently determine the phase of the tephra here closer than to the MLST or ULST. The finding of the LST presented here further strengthens the potential of tephrochronological studies in the south Scandinavian region.
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本文通过开展瑞典实物地质资料管理与服务跟踪研究,分析了瑞典实物地质资料管理与信息服务现状,掌握了瑞典在实物地质资料管理服务方面的政策法规、馆藏机构,以及资料汇聚、资料保管、资料数字化和信息服务现状;分析了瑞典岩芯高光谱红外成像2级数据产品服务的典型模式和可借鉴的经验,提出了对推进我国实物地质资料管理与信息服务的启示。  相似文献   

9.
Gotland is an island in the central Baltic, long recognized as the most outstanding outcrop of Silurian shallow-water marine sediments in the world. These represent deposition in tropical environments in an epeiric sea on the small continent of Baltica. The sediments are interbedded limestones and shales with subordinate sandstones and are developed as a carbonate platform on the underlying Precambrian, Cambrian and Ordovician. Particularly spectacular are reef deposits, rich in stromatoporoid sponges, which occur throughout the Gotland sequence. The sequence is almost undisturbed and provides an excellent field laboratoy to study a variety of Silurian facies.  相似文献   

10.
Till in Sweden     
The article gives a brief summary of till investigations in Sweden, which have long traditions. The main types of till and moraine forms occurring in Sweden are briefly defined and the till stratigrapy is described. A main part of the article is an extensive list of references.  相似文献   

11.
The Skellefte district in northern Sweden is host to abundant volcanogenic massive sulphide (VMS) deposits comprising pyritic, massive, semi-massive and disseminated Zn–Cu–Au ± Pb ores surrounded by disseminated pyrite and with or without stockwork mineralisation. The VMS deposits are associated with Palaeoproterozoic upper crustal extension (D1) that resulted in the development of normal faults and related transfer faults. The VMS ores formed as sub-seafloor replacement in both felsic volcaniclastic and sedimentary rocks and partly as exhalative deposits within the uppermost part of the volcanic stratigraphy. Subsequently, the district was subjected to deformation (D2) during crustal shortening. Comparing the distribution of VMS deposits with the regional fault pattern reveals a close spatial relationship of VMS deposits to the faults that formed during crustal extension (D1) utilising the syn-extensional faults as fluid conduits. Analysing the shape and orientation of VMS ore bodies shows how their deformation pattern mimics those of the hosting structures and results from the overprinting D2 deformation. Furthermore, regional structural transitions are imitated in the deformation patterns of the ore bodies. Plotting the aspect ratios of VMS ore bodies and the comparison with undeformed equivalents in the Hokuroko district, Japan allow an estimation of apparent strain and show correlation with the D2 deformation intensity of the certain structural domains. A comparison of the size of VMS deposits with their location shows that the smallest deposits are not related to known high-strain zones and the largest deposits are associated with regional-scale high-strain zones. The comparison of distribution and size with the pattern of high-strain zones provides an important tool for regional-scale mineral exploration in the Skellefte district, whereas the analysis of ore body shape and orientation can aid near-mine exploration activities.  相似文献   

12.
Zooarchaeology can contribute to issues that lie beyond the traditional boundaries of archaeology and paleobiology. The techniques and methods of zooarchaeology are essential to an historical ecology that has emerged as a powerful perspective for understanding indigenous peoples and landscapes of the neotropics, both in the present and the past. In order to realize fully its potential contributions to historical ecology, zooarchaeology must reject the arbitrary dichotomization of culture and nature and a viewpoint that considers indigenous peoples as passive reactors to environments rather than as active creators of human landscapes. Zooarchaeology must avoid the seduction of neo-Malthusian assumptions that underlie many cherished models, and should do more than simply list extinctions at the hands of prehistoric humans. Instead, zooarchaeologists should focus on the study of past human landscapes, explore dynamic disturbances and the human maintenance of habitat mosaics, record the infrastructure of intensive agriculture, and understand the indigenous logic of past biodiversity management. When archaeologists study the landscapes of previous human populations, they are engaged in the practice of historical ecology.  相似文献   

13.
Regional administrations present themselves in many different ways on the internet. A content analysis of regional websites in the Netherlands and Northwest Germany revealed this diversity. Geographical factors can partly explain these differences. Mapping the five principal aspects of the geographical representations of regional administrations revealed some spatial clusters. These regional representations are also linked to the geographical characteristics of regions. Competitive mid-sized regions focus more on economic items. Different types of peripheries vary much more in how they present themselves on the internet. The way regions present themselves is linked to the polarising influence of regional competition, but there is still considerable freedom for regions to present a distinct region image.  相似文献   

14.
U-bearing solid phases from Forsmark, Sweden, a proposed host for radioactive waste repositories, have been identified and characterized. Elevated dissolved U was found in some groundwater samples during the site investigations, prompting a need to study the local U geochemistry. Previous hydrochemical and whole-rock geochemical studies indicated that U was derived from local pegmatites, and mobilized and re-deposited during several geological events. In this study, down-hole gamma logs guided sampling of local pegmatites, cataclasites, and fracture fillings. Back-scattered electron-imaging, petrographic microscopy, and electron microprobe analyses were used to find and analyze U phases in thin sections. The results show that the principal U sources at Forsmark include pegmatitic uraninite (PbO up to ∼22 wt%) and metamict uranothorite. These primary minerals show variable degrees of alteration such as enrichment in Ca and Al and/or replacement by secondary Ca–U(VI)-silicates, haiweeite and uranophane. The haiweeite contains up to ∼5 wt% Al2O3, a chemical signature reflecting early (Proterozoic) events of hydrothermal fluid migration. Coffinitized, secondary uraninite is found in association with FeAl-silicates or Palaeozoic sulfide/sulfate minerals, indicating remobilization-precipitation and/or a secondary, sedimentary source of U. It is inferred that U was oxidized during geologically early periods. Later, U(IV) phases formed in fractures open to fluid circulation during the Palaeozoic. This study establishes the phases available as local U sources and/or sinks, and which will be considered in future isotopic and hydrochemical studies aimed to constrain the mechanisms and timing of water–U phase interaction.  相似文献   

15.
C.M. Law 《Geoforum》1983,14(2):169-184
The aim of the paper is to provide an outline of the influence of defence expenditure on British regional development during the last one hundred years. This topic has not received much attention since defence expenditure on the armed forces is usually considered non-basic, whilst expenditure on equipment is concealed amongst many industries. There are also important spin-off effects from this expenditure. The paper shows that defence expenditure favours southern and eastern regions of Britain and thus reinforces spatial trends from other sectors of the British economy. In addition to these regional effects there are significant impacts on local economies.  相似文献   

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Regional lithogeochemical surveys can be used to determine the geochemical characteristics of particular tectonic regions as well as mapping geochemistry in relation to geology and ore deposits at a larger scale. Regional lithogeochemistry is of particular value for assigning signatures to associations of igneous rocks which are related geochemically and geologically.The application of regional lithogeochemistry to mineral exploration is reviewed here with particular reference to the Mesozoic magmatic province of Mongolia. Geochemical data for granitoids are shown to have particular application to: (1) the classification and grouping of rocks of similar petrochemical and mineral compositions; (2) the compilation of tectonic and metallogenic maps; (3) the identification of metallogenic provinces and ore zones; and (4) predictive modelling to identify ore-bearing associations. Moreover, such data can be used to estimate the probable types and sizes of ore bodies associated with particular geochemical rock types. Regional lithogeochemistry thus forms an essential basis for prospecting for mineral deposits.  相似文献   

18.
室内设计中的可持续发展思维 ——室内生态设计   总被引:1,自引:0,他引:1  
人类社会发展到今天,摆在面前的事实是近两百年来工业社会给人类带来的巨大财富,人类的生活方式发生了全方位的变化。但工业化也极大地改变了人类赖以生存的自然环境,森林、生物物种、清洁的淡水和空气,以及可耕种的土地,这些人类赖以生存的基本物质保障在急剧地减少,气候变暖、能源枯竭、垃圾遍地......。如果按过去工业发展模式一味地发展下去,这个地球将不再是人类的乐园。现实问题迫使人类重新认真思考:今后应采取一种什么样的生活方式?是以破坏环境为代价来发展经济?还是注重科技进步,通过提高经济效益来寻求新的发展契机?我们正在经历…  相似文献   

19.
The author's chronology and pattern of the Late Weichselian deglaciation of southern Scandinavia, with emphasis on southwest Sweden, is based on multiple parameters. Björn E. Berglund (Lund) has proposed a drastic revision of this model. It is shown that Berglund's model leads to impossible consequences and is even contradicted by his own data. It is therefore found not tenable.  相似文献   

20.
The use of stable Pb isotopes for tracing Pb contamination within the environment has strongly increased our understanding of the fate of airborne Pb contaminants within the boreal forest. This paper presents new stable Pb isotope (206Pb/207Pb ratio) measurements of solid soil samples, stream water (from a mire outlet and a stream draining a forest dominated catchment) and components of Picea abies (roots, needles and stemwood), and synthesizes some of the authors’ recent findings regarding the biogeochemistry of Pb within the boreal forest. The data clearly indicate that the biogeochemical cycling of Pb in the present-day boreal forest ecosystem is dominated by pollution Pb from atmospheric deposition. The 206Pb/207Pb ratios of the mor layer (O-horizon), forest plants and stream water (mainly between 1.14 and 1.20) are similar to atmospheric Pb pollution (1.14–1.19), while the local geogenic Pb of the mineral soil (C-horizon) has high ratios (>1.30). Roots and basal stemwood of the analyzed forest trees have higher 206Pb/207Pb ratios (1.15–1.30) than needles and apical stemwood (1.14–1.18), which indicate that the latter components are more dominated by pollution derived Pb. The low 206Pb/207Pb ratios of the mor layer suggest that the upward transport of Pb as a result of plant uptake is small (<0.04 mg m−2 a−1) in comparison to atmospheric inputs (∼0.5 mg m−2 a−1) and annual losses with percolating soil-water (∼2 mg m−2 a−1); consequently, the Pb levels in the mor layer are now decreasing while the pool of Pb in the mineral soil is increasing. Streams draining mires appear more strongly affected by pollution Pb than streams from forested catchments, as indicated by Pb concentrations about three times higher and lower 206Pb/207Pb ratios (1.16 ± 0.01 in comparison to 1.18 ± 0.02). To what extent stream water Pb levels will respond to the build-up of Pb in deeper mineral soil layers remains uncertain.  相似文献   

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