Experimental study of the problem of frost weathering
DOI:
https://doi.org/10.26485/BP/1956/4/8Keywords:
geomorphological experiment, frost weathering, macrogelivation, microgelivation, slope formation, temperature amplitudeAbstract
Article in French.
ORIGINAL TITLE: Étude expérimentale du problème de la gélivation
The article presents the possibilities of applying experimental methods in geomorphological research, specifically in the study of periglacial processes occurring over short time scales. Laboratory experiments made it possible to reproduce frost weathering of various rock types and to artificially simulate solifluction processes. It was demonstrated that the intensity of frost weathering is largely dependent on environmental conditions. In dry environments, this process is almost ineffective, whereas in moist conditions – especially when samples are partially immersed in water – it proceeds much more rapidly. The amplitude of temperature fluctuations directly influences the rate of rock disintegration: under climates with large thermal variations (Siberian type), frost weathering is approximately three times more intense than in environments with smaller temperature changes (Icelandic type).
The variability of rock susceptibility to weathering depends on their texture, mechanical properties and geomorphological history. Even within a single lithological group, such as limestones, susceptibility may differ by a factor of several hundreds. The author distinguishes two main types of frost weathering: macrogelivation (associated with existing fractures and rock structure) and microgelivation (independent of rock texture). Experimental observations also confirm the significance of the granulometric composition of weathering products, which determines the internal friction coefficient of material transported downslope under periglacial conditions.
The results indicate that, over long timescales, these processes lead to the development of slopes with similar forms and mean inclinations, resulting from the grain-size characteristics of the material. The relationship between the properties of frost weathering products and slope morphometry opens new perspectives for the advancement of quantitative geomorphology.
References
1. Boye, M. - Glaciaire et periglaciaire de l 'Ata Sund nord-oriental, Groenland. Hermann, Paris 1950.
2. Corbel, J. - Sols stries et eboulis ordonnes. Rev. Geomorph, Dyn., 1954, nr 1.
3. Corbel, J. - Les sols polygonaux: observations, experiences, genese. Rev. Geomorph. Dyn., 1954, nr 2.
4. Daubree, A. - Etude synthetique de geologie experimentale. Paris 1879.
5. Leuzinger, V. R. - Os metodos da geomorfologia. C. R. Congr. Int. Geogr. Lisbonne 1949, t. 4, Lisbonne 1952.
6. Tricart, J. - Le modele periglaciaire. Cours de geomorphologie, 2e partie, fase. 1, CDU, Paris 1950.
7. Tricart, J. - La geomorphologie et la notion d'echelle. Rev. Giomorph. Dyn., 1952, nr 5.
8. Velikanov, M. A. - Problema formirovaniya retchnego rusla (la reproduction du lit des riviere3). Akal. Nauk SSSR, Gidrologia, t. 70, 1950.
