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Atlantic Gulfs, Estuaries, and Cliffs

Published online by Cambridge University Press:  01 May 2009

C. A. Cotton
Affiliation:
(Victoria University College, Wellington)

Abstract

The morvan theory with slight modification fits the structure of the coasts of south-western Britain better than the fault theory of Atlantic coasts advanced by Suess.

The English Channel and St. George's Channel have been long in existence, and are more probably of tectonic than erosional origin.

Erosional deepening of the valleys which were drowned by the Flandrian transgression to become estuaries must have taken place almost entirely in glacial ages when the level of the ocean has been low. The tempo of coastal erosion, both subaerial and marine, has been rather slow, however, owing to the great width of the continental shelf. Thus shoreline details survive from an interglacial age.

In regions with a narrower continental shelf, deepening and also extensive enlargement of valleys across coastal lands have taken place in each glacial age of low ocean level, and interglacial aggradations have determined terrace levels at consistent heights in the inland valleys of large rivers, as exemplified in Portugal.

The cliffs of Cornwall and Wales show traces of two cycles or marine retrogradation separated by a withdrawal of the sea. Thus the “bevel”, or “coastal slope” above modem cliffs can be accounted for as an ancient sea-cliff graded subaerially during the period of low ocean level.

Type
Articles
Copyright
Copyright © Cambridge University Press 1951

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References

REFERENCES

Arber, E. A. N., 1911. The Coast Scenery of North Devon.Google Scholar
Arber, M. A., 1949. Cliff problems of Devon and Cornwall. Geog. Journ., 114, 191–7.Google Scholar
Arkell, W. J., 1943. In discussion of GREEN, 1943.Google Scholar
Baulig, H., 1928. Le Plateau Central de la France. Paris: Colin.Google Scholar
Baulig, H., 1935. The Changing Sea Level.CrossRefGoogle Scholar
Baulig, H., 1948. Problèmes des terrasses. VI Rapp. Comm. Terr. Pli. Pleist., Union Géog. Internat.Google Scholar
Calkin, J. B., and Green, J. F. N., 1949. Palaeoliths and terraces near Bournemouth. Proc. Prehist. Soc. for 1949, 2137.Google Scholar
Challinor, J., 1930. The hill-top surface of North Cardiganshire. Geography, xv, Dec., 8 pp.Google Scholar
Challinor, J., 1931. Some coastal features of North Cardiganshire. Geol. Mag., lxviii, 111121.CrossRefGoogle Scholar
Challinor, J., 1948. Convex erosion slopes, with special reference to North Cardiganshire. Geography, xxxiii, 2731.Google Scholar
Challinor, J., 1949. A principle in coastal geomorphology. Geography, xxxiv, 212215.Google Scholar
Clapp, C. H., 1913. Contraposed shorelines. Jour. Geol., xxi, 537540.CrossRefGoogle Scholar
Cotton, C. A., 1948. Volcano-eustatism, positive or negative? Geol. Mag., lxxxv, 201–2.Google Scholar
Davis, W. M., 1909. The systematic description of land forms. Geog. Jour., xxxiv, 300326.CrossRefGoogle Scholar
Davis, W. M., 1912 a. Die erklärende Beschreibung der Landformen. Leipzig: Teubner.Google Scholar
Davis, W. M., 1912 b. Relation of geography to geology. Bull. Geol. Soc. Amer., xxiii, 93124.Google Scholar
Davis, W. M., 1912 c. A geographical pilgrimage from Ireland to Italy. Ann. Ass. Amer. Geog., ii.Google Scholar
Dewey, H., 1916. On the origin of some river gorges in Cornwall and Devon. Quart. Jour. Geol. Soc., lxxii, 65–9.Google Scholar
Feio, M., 1947. Os terraços do Guadiana. Lisboa: Centro do Estudos Geográficos.Google Scholar
Green, J. F. N., 1936. The terraces of southernmost England. Quart. Journ. Geol. Soc., xcii, pp. lviii–Ixxxviii.Google Scholar
Green, J. F. N., 1941. The high platforms of east Devon. Proc. Geol. Assoc., lii, 3652.Google Scholar
Green, J. F. N., 1943. The age of the raised beaches of South Britain. Proc. Geol. Assoc., liv, 129140.Google Scholar
Green, J. F. N., 1946 a. The terraces of Bournemouth, Hants. Proc. Geol. Assoc., lvii, 82111.Google Scholar
Green, J. F. N., 1946 b. The history of the Bourne and its valley. Proc. Bournemouth Nat. Hist. Soc., xxxv, 1622.Google Scholar
Green, J. F. N., 1949. The history of the River Dart, Devon. Proc. Geol. Assoc., lx, 105124.CrossRefGoogle Scholar
Green, J. F. N., 1950. A tour of the terraces of the Avon and Stour. Proc. Bournemouth Nat. Hist. Soc., xxxix, 52–9.Google Scholar
Greenly, E., 1938. The age of the mountains of Snowdonia. Quart. Jour. Geol. Soc., xciv, 117124.Google Scholar
Guilcher, A., 1950. Nivation, cryoplanation et solifluction quaternaires dans les collines de Bretagne Occidentale et du Nord du Devonshire. Revue de Géomorphologie Dynamique, i, 5378.Google Scholar
Hanson-Lowe, J., 1938. Bearing of the morphologic data in the Channel Islands on the eustatic theory. Journ. Geomorph., i, 91103.Google Scholar
Hill, J. B., and Macalister, D. A., 1906. Geology of Falmouth and Truro. Mem. Geol. Surv.Google Scholar
Hollingworth, S. E., 1938. Recognition and correlation of high-level erosion surfaces in Britain. Quart. Jour. Geol. Soc., xciv, 5584.CrossRefGoogle Scholar
Jones, O. T., 1924. The Upper Towy drainage system. Quart. Jour. Geol. Soc., lxxx, 568609.Google Scholar
Jones, O. T., 1930. Some episodes in the geological history of the Bristol Channel region. Brit. Assoc. Adv. Sci., Bristol, 1930 (Pres. Addr. Sec. C).Google Scholar
Lautensach, H., 1945. Formaçao dos terraços interglaciários do Norte de Portugal da época glaciária. Publ. Soc. Geol. Port., 1.Google Scholar
Lefèvre, M. A., 1935. La Basse-Meuse. Soc. Belg. d'Et. Géog., Mém., 1.Google Scholar
Macar, P., 1936. Quelques remarques sur la géomorphologie des Cornouail-les et du sud de Devonshire. Ann. Soc. Géol. de Belg., lx, 152169.Google Scholar
Meynier, A., 1947. Influences tectoniques sur le relief de Bretagne. Ann de Géog., lxi, 170–7.Google Scholar
Migliorini, C., 1949. I cunei composti nell' orogenesi. Bull. Soc. Geol. Ital., lxxii, 29142.Google Scholar
Putnam, W. C., 1937. The marine cycle of erosion for a steeply sloping shoreline of emergence. Jour. Geol., xlv, 844850.Google Scholar
Putnam, W. C., 1942. Geomorphology of the Ventura region, California. Bull. Geol. Soc. Amer., liii, 691754.Google Scholar
Reid, C., and Flett, J. S., 1907. Geology of the Land's End district. Mem. Geol. Surv.Google Scholar
Ribeiro, O., 1949. Le Portugal Central (livret-guide excurs. C, Cong. Géog. Internat.), Lisbonne.Google Scholar
Sawicki, L., 1912. Einebnungsflächen in Wales und Devon. CR. Soc. Sci. Varsovie, v, 123 ff.Google Scholar
Shepard, F. P., 1948. Submarine Geology. New York: Harper.Google Scholar
Stearns, H. T., 1945. Late geologic history of the Pacific basin. Amer. Journ. Sci., 243, 614626.Google Scholar
Suess, E., 1906. The Face of the Earth. Oxford.Google Scholar
Wooldridge, S. W., and Linton, D. L., 1938. Influence of Pliocene transgression on the geomorphology of Southeast England. Journ. Geomorph., 1, 4054.Google Scholar
Zeuner, F. E., 1945. The Pleistocene Period. London: Ray Society.Google Scholar