| dc.description.abstract | There are wide, semispherical, hills in the south-west England. The highest, Dartmoor (621 m. asl.) is built of
granites which, as a huge batholit, was formed during the Hercynian orogene. Numerous rocky forms, which can be
observed on wide plateaus, slopes and lower ridges are commonly known. They make different forms: towers, crags,
pillars, stacks etc. Such forms are of different origin and they can be observed in different dimatic zones. Such
forms in England were described by D.L. Linton (1955), J. Palmer, R. Neilson (1962). The theory of weathering
origin of granitic rocks in Dartmoor was presented by D.L. Linton (1955) and it may be called as a dassical one.
He connected development of rocks, called "tors", with deep weathering during the Tertiary and, the during the
Quaternary, the thick weathered cover was carried away. The cross - sections (fig, 3, 4) show that there are
solifluctional covers on slopes and rocks are in different stages of development. Some of them are typical,
periglacial rocky fields and there are well preserved fragments of cryoplanation surfaces, with frost diffs, on
slopes. These forms are not only Tertiary horsts uncovered from the weathered material during periglacial
processes but they were also modelled by frost processes.
To Lintons theory abont 2 phase origin (weathering and disclosure) the third phase, of modelling in periglacial
processes, should be added. Disclosure could take place in different ways: by dissecting and planation in
moderately humid climate (interglacials and Holocene), by cryoplanation and solifluction in periglacial climate.
Washing aut and mechanical suffosion play contemporarily an important role. | en_EN |
