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Mappings and Geochronological Investigations in Some Moraine Areas of South-Central Sweden |
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Geografiska Annaler: Series A, Physical Geography,
Volume 47,
Issue 2,
1965,
Page 73-82
StrömbergBo,
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PDF (4543KB)
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ISSN:0435-3676
DOI:10.1080/04353676.1965.11879715
出版商:Taylor&Francis
年代:1965
数据来源: Taylor
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2. |
Plastically Sculptured Detail Forms on Rock Surfaces in Northern Nordland, Norway |
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Geografiska Annaler: Series A, Physical Geography,
Volume 47,
Issue 2,
1965,
Page 83-140
DahlRagnar,
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PDF (58619KB)
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摘要:
AbstractAs regards the greater part of Scandinavia, our knowledge of the distribution of plastically sculptured detail forms on rock surfaces (p-forms), both regionally and topographically, is incomplete. In northern Nordland the author found a great many localities rich inp-forms, such asSichelwannen, cavettos (Germ. Hohlkehle), channels, bowls, pot-holes, etc. They occur between 0 and 600 m a.s.l. with the highest frequency between 250 and 550 m a.s.l. An account is given of thep-forms found in various rocks and various terrains in seven examined areas (A—G). Thep-forms are not restricted to certain rocks. The morphology seems to have influenced the location of thep-forms. Most of them were found on plateau surfaces, where the direction of ice movement was distinctly deflected. In most cases the ice movement in the original direction was prevented by mountains or hills situated at a distance of 2,5–3 km from the localities rich inp-forms. Generally there seems to be a connection between the deviations in the direction of ice movement and the creation ofp-forms.A systematic treatment of the typicalp-forms is given. The validity of earlier theories of the genesis of these forms is discussed in connection with the facts discovered in the field, a discussion which leads to some fresh conclusions and proposed interpretations.Most of the typicalp-forms are thought to have been eroded by sub-glacial melt-water streams flowing with high velocity in rather concentrated routes or tunnels. With the support of Glen's theory (1954) on the outflows of glacier lakes by enlargement of deep water-filled holes in glaciers, the author puts forward an interpretation of the fact that thep-forms are orientated in the direction of ice movement.Thep-forms with polished surfaces which resemble cavitation forms are discussed as regards their dependence on cavitation and corrasion. Laboratory experiments are necessary to solve this problem.
ISSN:0435-3676
DOI:10.1080/04353676.1965.11879716
出版商:Taylor&Francis
年代:1965
数据来源: Taylor
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