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The Formation and Shape of Drumlins and their Distribution and Orientation in Drumlin Fields

  • Ian J. Smalley (a1) and David J. Unwin (a1)

Abstract

If glacial till contains more than a certain minimum boulder content, it is dilatant and requires a much larger stress to initiate shear deformation than to sustain it. If the stress level at the glacier–terrain interface drops below a certain critical level, or the till reaches its critical boulder-content density, then the till beneath the glacier packs into stable obstructions. These are shaped into streamlined forms by the glacier and are found distributed at random in drumlin fields. Due to drumlin coalescence there is a normal distribution of drumlin axes about the direction of ice movement.

Résumé

La formation et morphologic de drumlins et leur répartition et orientation en champs de drumlins. Si un argile à blocaux contient plus d’une certaine quantité minimum de blocaux, il est dilatable et exige une plus grande tension pour débuter une déformation par cissaillement que pour le soutenir. Si le niveau de tension entre le glacier et le terrain descend au-dessous d’un certain niveau critique, ou si l’argile à blocaux atteint sa densité critique de blocaux, alors l’argile à blocaux au-dessous du glacier s’agglomère et forme des obstacles stables de formes carénées et distribués au hasard en champs de drumlins. A cause de leur coalescences, les axes des drumlins s’alignent avec la direction du mouvement glaciaire en une répartition normale.

Zusammenfassng

Über Entstehung und Gestalt von Drumlins.sowie deren Verteilung und Orientierung in Drunlinfeldern. Wenn glazialer Geschiebemergel mehr als ein bestimmtes Minimum von Geröll enthält, ist er dilatant und benötigt eine weit höhere Spannung zur Einleitung von Scherformationen als zu deren Fortführung. Sinkt das Spannungsniveau zwischen Gletscher und Untergrund unter einen bestimmten kritischen Wert oder erreicht der Geschiebemergel seinen kritischen Geröllgehalt, so häuft sich das Geschiebe unter dem Gletscher zu stabilen Hindernissen auf. Diese werden vom Gletscher stromlinienförmig gestaltet und erscheinen in zufälliger Verteilung als Drumlinfelder. Infolge der Verschmelzung von Drumlins haben clie Drumlinachsen eine Normalverteilung um die Richtung der Eisbewegung.

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Copyright

References

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Alden, W. C. 1905. The drumlins of south-eastern Wisconsin. U.S. Geological Survey. Bulletin No. 273, p. 946.
Alden, W. C. 1911. Radiation of glacial flow as a factor in drumlin formation. Bulletin of the Geological Society of America. Vol, 22, p. 73334. [Abstract. Discussion by H. Fairchild, p. 734.]
Andrade, E. N. da C. Fox, J. W. 1949. The mechanism of dilatancy. Proceedings of the Physical Society, Sect. B, Vol. 62, Pt. 8, p. 483500.
Aronow, S. 1959. Drumlins and related streamline features in the Warwick-Tokio area. North Dakota. American Journal of Science, Vol. 257, No. 3, p. 191203.
Boswell, P. G. H. [1961.] Muddy sediments. Cambridge, W. Heifer and Sons, Ltd.
Charlesworth, J. K. 1957. The Quaternary era, with special reference to its glaciation. London, Edward Arnold. 2 vols.
Chorley, R. J. 1959. The shape of drumlins. Journal of Glaciology, Vol. 3, No. 25, p. 33944.
Clark, P. J. Evans, F. C. 1954. Distance to nearest neighbour as a measure of spatial relationships in populations. Ecology, Vol. 35. No. 4, p. 44553.
Ebers, E. 1926. Die bisherigen Ergebnisse der Drumlinforschung. Eine Monographie der Drumlins. Neues Jahrbuch für Mineralogie, Geologie und Paläonlologie. Beilagebande, 53, Abt. B, p. 153270.
Fairchild, H. 1911. Discussion. [See Alden, 1911, p. 734.]
Flint, R. F. [1957.] Glacial and Pleistocene geology. New York, John Wiley and Sons, Inc.
Gravenor, C. P. 1953. The origin of drumlins. American Journal of Science. Vol. 251, No. 9, p. 67081.
Hagget, P. [1965.] Localional analysis in human geography. London, Edward Arnold.
Heidenreich, C. 1964. Some observations on the shape of drumlins. Canadian Geographer, Vol. 8, No. 2, p. 10107
Kendall, M. G. Smith, B. B. 1951. Tables of random sampling numbers. Cambridge, University Press. (Tracts for Computers, No. 24.)
MacNeill, R. H. 1965. Variation in content of some drumlins and tills in south-western Nova Scotia. Maritime Sediments, Vol. 1, No. 3. p. 1619.
Mead, W. J. 1925. The geologic rôle of dilatancy. Journal of Geology, Vol. 33, No. 7, p. 68598.
Nye, J. F. 1965. The flow of a glacier in a channel of rectangular. elliptic or parabolic cross-section. Journal of Glaciology, Vol. 5, No. 41, p. 66190.
Reed, B. and others. 1962. Some aspects of drumlin geometry, by B. Reed. C. J. Galvin, Jr., and J. P. Miller. American Journal of Science. Vol. 260, No. 3, p. 20010.
Reynolds, G. 1885. On the dilatancy of media composed of rigid particles in contact. Philosophical Magazine, Fifth Ser., Vol. 20, No. 127, p. 46981.
Smalley, I. J. 1962. Packing of equal O-spheres. Nature, Vol. 194, No. 4.835, p. 1271.
Smalley, I. J. 1964. Representation of packing in a elastic sediment. American Journal of Science, Vol. 262, No. 2. p. 24248.
Smalley, I. J. 1966[a]. Contraction crack networks in basalt flows. Geological Magazine, Vol. 103, No. 2, p. 11014.
Smalley, I. J. 1966[b]. Drumlin formation: a rheological model. Science. Vol. 151, No. 3716, p. 137980.
Taylor, F. B. 1931. Distribution of drumlins and its bearing on their origin. Bulletin of the Geological Society of America, Vol. 42, No. 1. p. 201. [Abstract.]
Thornbury, W. D. [1954.] Principles of geomorphology. New York. John Wiley and Sons, Inc.
Thwaites, F. T. 1957. Outline of glacial geology. Revised edition. Ann Arbor. Edwards Brothers Inc.
Vernon, P. 1966. Drumlins and Pleistocene ice flow over the Ards Pcninsula/Strangford Lough area, County Down. Ireland. Journal of Glaciology, Vol. 6, No. 45. p. 40109.

The Formation and Shape of Drumlins and their Distribution and Orientation in Drumlin Fields

  • Ian J. Smalley (a1) and David J. Unwin (a1)

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