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13
pages
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Français
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Documents
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1975
Description
The Flandrian deposits filling in the depression corresponding to the present marshes and polderlands around Dol-de-Bretagne are constituted by marine sediments, sands and silts, with intercalations of peat layers. Radio-carbone dates and pollen analytical dates show that these different peaty layers were formed at the end of the Boreal period, towards 8 200 B.P., at the end of the Atlantic and the beginning of the Subboreal, betwen 5 850 and 5 400 B.P. , during the Subboreal betwen 3 900 and 3 450 B.P. and during the Subatlantic, from 3 000 years B.P. onwards. It seems necessary to suggest slowing down in the transgression (or even regressions) to explain the growing of the peat. A curve of the variations of the sea-level cannot be drawn because of the differential compaction of the sediments under the marshes.
12 pages
Source : Persée ; Ministère de la jeunesse, de l’éducation nationale et de la recherche, Direction de l’enseignement supérieur, Sous-direction des bibliothèques et de la documentation.
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Publié par
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Publié le
01 janvier 1975
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Langue
Français
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Poids de l'ouvrage
2 Mo