| Diverse hypotheses put forward by historians as to the origins of the Isle of R6 haveinvariably caused ardent controversies. However, it is now certain that this territory waslinked to the neighbouring continent, of which it formed an integral part, well before theappearance of man in the area. To the north and south, two promontories extending on eitherside limited the valleys of the Niort S~vre and the Charente. Their alluvial deposits extendedmuch further than the present estuaries. It was during the quarternary era that the mainformation of the island began. The last ice age was ending and the ice which covered thewhole territory was melting, consequently causing a slow rise in the level of the Atlantic. Theprogressive increase of water caused the immersion of the lowest areas and only the highestparts resulting from geological movement in the secondary era were preserved. Thus at first,the sea covered large portions of the land, creating four islets of jurassic limestone : Loix,Les Portes, Ars and Saint-Martin. These subsisted, separated from each other by the waters.Simultaneously to the east, the ocean flooded the section between the point of Sablanceauxand that of Saint-Marc at La Pallice, thus isolating the last band of visible land from the restof the continent. A long period followed, during which the area between each island wasfilled in by marine deposits. A slight withdrawal of the waters enabled the marshes to form,linking the former separated parts. For many years after the appearance of man, these marshareas were at the mercy of the sea. The outline of the island was however sketched outhenceforth and man was soon to perfect what nature had patiently begun. |
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