Les Blocs d'estran a Saint-Fabien-Sur-Mer, Estuaire Maritime du Saint-Laurent, Quebec

Authors

  • Jean-Claude Dionne Direction des Terres, Environnement Canada c.p. 10100, Sainte-Foy, Que., G1V 4H5

DOI:

https://doi.org/10.4138/1348

Abstract

RÉSUMÉ L'estran de L’anse à Mercier, à Saint-Fabien-sur-Mer, c&x#F4;te sud de L’estuaire maritime du Saint-Laurent, est en grande partie couvert de blocs. lis ont jusqu'à 5 m de diamètre, reposent sur de L’argile marine post-glaciaire et avpartiennent à deux grandée categories lithologiques: roches ignées et métamorphiques, d'âge Précambrien, provenant du Bouclier Laurentidien â plus de 25 km au nord, et roches sédimentaires, d'âge Paléozoique, provenant des crêtes appalachiennes et des plates-formes littorales avoisinantes. Des aomptages faits sur 9900 blocs d'estran ont donné une proportion de 57% d'éléments laurentidiens et 43% d'éléments appalachiens. L'absence de till ou de dépôt norainique dans la région et la position stratigraphique des blocs à la surface de sédiments fins marins, d'âge post-glaciaire, permettent de conolure que les glaces flottantes sont le prinicpal agent de transport et de mise en place des blocs. Various boulder accumulations occur at Mercier Cove, Saint-Fabien-sur-Mer, on the south shore of the Lower St. Lawrence Estuary. Boulders, up to 5 m in diameter, are found on marine postglacial deposits of thick clay. The boulders are composed of two main lithologies: Precambrian igneous and metamorphie rocks from the Laurentidian Shield over 25 km to the north, and Paleozoic sedimentary rocks from the surrounding Appalachian ridges and shore platforms. Of the 9900 boulders counted throughout the tidal zone, 57% are Laurentidian rocks and 43% Appalachian. As there is no evidence of glacial drift in the area, and as the boulders overlay fine marine sediments of postglacial age, drift ice can be considered as the principal agent of transportation and deposition.

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Published

1979-01-01

How to Cite

Dionne, J.-C. (1979). Les Blocs d’estran a Saint-Fabien-Sur-Mer, Estuaire Maritime du Saint-Laurent, Quebec. Atlantic Geoscience, 15(1). https://doi.org/10.4138/1348

Issue

Vol. 15 No. 1 (1979)

Section

Reports

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