Asymmetrical slope development in the Chiltern Hills
DOI:
https://doi.org/10.26485/BP/1972/21/5Keywords:
chalk dry valleys, fluvial processes, asymmetry development, Southern EnglandAbstract
The asymmetrical nature of Chalk dry valleys in Southern England is discussed with reference to some of the Chiltern valleys. The periglacial origin of the asymmetry is not disputed. Instead, a model of asymmetrical slope and valley development is proposed in which the importance of fluvial processes in periglacial environments is stressed. Sorne implications with respect to the origin of chalk dry valleys are outlined. It is argued that while the major valleys may very well be explained in terms of a ground water hypothesis in accordance with a progressively falling watertable throughout the Pleistocene, the pedods of periglacial conditions promoted: (a) the asymmetrical modification of the slopes of already existing valleys and (b) the initiation of the periglacial valleys and gullies - les vallons en berceau - upon the frozen subsoils existing at that time.
References
Alexandre, J., 1958 - Le modelé quaternaire de l'Ardennes Centrale. Ann. Géol. Soc. de Belgique, vol. 81; p. 213-332.
Avery, B., et al., 1959 - The origin and development of brown earths on clay-with- flints and coombe deposits. Jour. Soil Sci. vol. 10; p. 177-195.
Avery, B. W., 1964 - The soils and land use of the district around Aylesbury and Hemel Hempstead. Memoir, The Soil Survey of Great Britain, H.M.S.O.
Brown, E. H., 1964 - Field Meeting in the Chilterns, near Tring. Proceedings Geologists Association, vol. 75; p. 341-5.
Büdel, J., 1953 - Die periglazialmorphologischen Wirkungen des Eiszeitklima auf ganzen Erde. Erdkunde, Bd. 7; p. 249-266.
Bull, A. J., 1940 - Cold conditions and landforms in the South Downs. Proceedings Geologists Association, vol. 51; p. 63-71.
Cavaillé, A., 1953 - Les vallées dissymétriques dans les pays de la moyenne Garonne. Bull. Soc. Géogr., Comité Trav. et Scient., 1953; p. 51-68.
Clark, M. J., Lewin, J., & Small, R. J., 1967 - The Sarsen stones of the Marlborough Downs and their geomorphological significance. Southampton Research series in Geography, 4; p. 3-40. University of Southampton.
Culling, E. W. H., 1956 - The Upper Reaches of the Chiltern Valleys. Proceedings Geologists Association, vol. 67; p. 346-68.
Czudek, T., 1964 - Periglacial slope development in the area of the Bohemian Massif in Northern Moravia. Biuletyn Peryglacjalny, No. 14; p. 169-195.
Dylik, J., 1956 - Esquisse des problèmes périglaciaires en Pologne. Biuletyn Peryglacjalny, No. 4; p. 57-71.
Dylikowa, A., & Klatkowa, H., 1956 - Exemple du modelé périglaciaire du Plateau de L6dz. Biuletyn Peryglacjalny, No. 4; p. 239-53.
Fagg, C. C., 1954 - The coombes and embayments of the Chalk Escarpment. Trans. Croy. Nat. Hist. Soc. vol. 9; p. 117-31.
French, H. M., 1967 - The asymmetrical nature of Chalk dry valleys in Southern England. Unpublished Ph. D. Dissertation, University of Southampton.
Geukens, F., 1947 - De asymmetric der drage dalen van Haspengower. Natuurwet. Tidschr., 1, p. 13-18.
Gloriod, A., & Tricart, J., 1952 - Etude statistique des vallés asymmétriques de la feuille St. Pol au 1 : 500000. Rev. Géom. Dyn. 3, p. 88-98.
Grimbérieux, J., 1955 - Origine et asymmétrie des vallées sèches de Hesbaye. Ann. Géol. Soc. de Belgique, vol. 78; p. 267-286.
Helbig, K., 1965 - Asymmetrische Eiszeittäler in Suddeutschland und Östereich. Würzburger Geog. Arbeiten, H. 14; 103 p.
Klatkowa, H., 1965 - Niecki i doliny denudacyjne w okolicach Łodzi (résumé: Vallons en berceau et vallées sèches aux environs de Łódź); Acta. Geogr. Lodziensia, 19; p. 1-141.
Ollier, C. D., & Thomasson, A. J., 1957 - Asymmetrical valleys of the Chiltern Hills. Geog. Jour., vol. 123; p. 71-80.
Peltier, L. C., 1950 - The geographic cycle in periglacial regions as it is related to climatic geomorphology. Ann. Assac. Amer. Geog., vol. 40 (3); p. 214-236.
Penck, A., 1924 - The Morphological Analysis of Landforms (translated by H. Czeck and K. C. Boswell, 1953). London.
Robitaille, B., 1960 - Présentation d'une carte géomorphologique de la région de Mould Bay, Ile Prince Patrick, T.N.0. Canadian Geographer, 15, p. 39-43.
St-Onge, D. A., 1964 - Géomorphologie de l'Ile Ellef Ringes, T. du Nord-Ouest. Etude Géographique, 38; Ottawa.
Taillefer, F., 1944 - La disymmétrie des vallées gasconnes. Rev. Géog. des Pyr. et du Sud-Ouest, vol. 15, p. 153-181.
Thomasson, A. J., 1961 - Some aspects of the drift deposits and geomorphology of S. E. Hertfordshire. Proceedings Geologists Association, vol. 72; p. 287-302.
Tricart, J., 1947 - Sur quelques indices géomorphométriques C. R. Acad. Sci. Paris 225, p. 747-9.
Williams, R. G. B., 1968 - Periglacial erosion in Southern and Eastern England. Biuletyn, Peryglacjalny, No. 17; pp. 311-35.
Wood, A., 1942 - The development of Hillside Slopes. Proceedings Geologists Association, vol. 53, p. 128-39.
