Publikationsdatum:
2004-03-01
Beschreibung:
Coarse sand accumulations are polygenic microforms that attain a width of several metres, a height up to 30-40 cm, a gradient of 8-12° and a slope length up to 1 m. These accumulations are frequent in the gruss-covered plateaus of the granite mountains of central and northern Portugal, but they have been described in other mountain areas (i.e. Cairngorms, Scotland). Though these microforms are frequent features, studies on them are rare. They have been attributed to complex genesis controlled primarily by aeolian processes, but also by wash and cryogenic dynamics. Results presented here add new insights into the origin of the sand accumulations and emphasize the importance of rainsplash-saltation induced by oblique rainfall as the main transportation mechanism. The study was conducted in the Serra da Estrela, a granite mountain in central Portugal (1993 m above sea level) and is supported by a detailed mapping of the orientation of the accumulations, monitoring of the surface material and analysis of meteorological data. The results are particularly significant since they indicate that the coarse sand accumulations are very active features that show a clear climatic and ecological signal. © 2004 John Wiley and Sons, Ltd.
Print ISSN:
0885-6087
Digitale ISSN:
1099-1085
Thema:
Architektur, Bauingenieurwesen, Vermessung
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Geographie
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