Dynamic Geomorphology of the Drumlin Coast of Southeast Cape Breton Island

Authors

  • Ying Wang Nanking University, The People's Republic of China
  • D. J. W. Piper Atlantic Geoscience Centre, Geological Survey of Canada Bedford Institute of Oceanography, Dartmouth, W.S. B2Y 4A2

DOI:

https://doi.org/10.4138/1385

Abstract

The southeastern coast of Cape Breton Island from Gabarus Bay to Framboise Cove has been investigated as a typical example of a drumlin coast. Landforms have been mapped from ground observations and air photographs. Time series of coastal profiles of both beaches and eroding drumlin cliffs have been measured. Nearshore sediment distribution has been mapped. An analysis has been made of wind and wave frequency and direction data. Four coastal segments are distinguished: (1) the south coast of Gabarus Bay has rock-cored drum-11ns separated by small barrier beaches; (2) the coast around Winging Point has a relatively stable depositional tombolo coast; (3) Fourchu Bay and Framboise Cove are developed in an area of thick till drumlins, and consist of barrier bars backed by lagoons and drumlins; and (4) the Fourchu Head and Red Cape are rocky coastlines from which all till has been removed by marine erosion, The geomorphologlcal evolution is a consequence of the initial drumlin landscape, the availability of a wide range of sediment sizes, and the type and intensity of marine erosion processes including the effects of transgression. Two types of coast are developed: a) in irregular hilly areas, where the till is thin and occurs in rock-cored drumlins; and b) in valley areas, where thick till drumlins are found. In each of these types, three stages of coastal development are distinguished. These represent the effect of differing rate of maturation, dependent on the configuration of drumlins and varying type and intensity of marine erosion. RÉSUMÉ Depuis la baie de Gabarua jusqu'à l'anse Framboise, la côte sud-est de l'ile du Cap-Breton a été étudiée en tant qu'exemple type d'une côte à drumlins. Les formes de relief ont été cartographies à partlr d'observations sur le terrain et de photographies aériennes. On a mesure à différents intervalles de temps, des séries de proflis côtiers comprenant des plages ainsi que des falaises de drumlins soumises à l’érosion. La distribution des sédiments littoraux a été cartographiée. On distingue quatre environnements côtiers. Le littoral sud de la baie de Gabarus est caractérise par des drumlins à noyau rocheux separes par des plages barrières de faibles dimensions. La côte à tombolos qui entoure la pointe Winging est un environnement de déposition relativement plus stable. Dans les régions de la baie Fourchu et de l'anse Framboise, des drumlins constitues d'un till epais sont 2 l'origine d'une côte barrière appuyée par des langunes et des drumlins. Les côtes rocheuses du cap Fourchu et de Red Cape ont été denudfies de leur till par l’action érosive de la mer. L'évolution géomorphologique de la côte ressort du paysage à drumlins original, de la disponibilité d'une vaste gamme de sédiments, ainsi que du type et de l'intensité des processus d’érosion marine, y compris les effets de la transgression. On reconnect deux types de côtes: l'une caractérisée par un paysage semé de collines oul'on retrouve un till mince associé à des drumlins à noyau rocheux; l’autre, que l'on retrouve dans les vallées, se distingue par d'épais drumlins constitues de till. Chacun de ces types de côtes se développé en trois étapes correspondent à des régimes de maturation différents qui dépendent de la configuration des drumlins ainsi que de l’intenuité et du caractére particuller de l’érosion marine. [Traduit par le journal]

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Published

1982-01-01

How to Cite

Wang, Y., & Piper, D. J. W. (1982). Dynamic Geomorphology of the Drumlin Coast of Southeast Cape Breton Island. Atlantic Geoscience, 18(1). https://doi.org/10.4138/1385

Issue

Vol. 18 No. 1 (1982)

Section

Articles

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