The Paris Basin is one of the major geological regions of France having developed since the Triassic on a basement formed by the Variscan orogeny.
Extent
The region usually regarded as the Paris Basin is rather smaller than the area formed by the geological structure. The former occupies the centre of the northern half of the country, excluding Eastern France. The latter extends from the hills just south of
Calais to
Poitiers and from
Caen to the brink of the middle Rhine Valley, east of
Saarbrücken.
Geography
The countryside is one of plains and plateaux of limited altitude. In the south-east and east the plain of
Champagne and the
Seuil de Bourgogne differential erosion of the strata has left low scarps with the dip slopes towards the centre. The varying nature of the clays, limestones and chalk gives rise to the characteristics of the regions such as
Champagne Humide (Damp Champagne),
Champagne Pouilleuse (lousy or shall we say, poor Champagne), the
Pays de Caux and the
Pays de Bray.
Structure
It is a
geological basin of
sedimentary rocks. It overlies geological
strata disturbed by the Variscan orogeny and forms a broad shallow bowl in which successive marine deposits from throughout periods from the
Triassic to the
Pliocene were laid down: their extent generally diminishing with time.
To the west, the strata folded by the Variscan, rise from below it in the hills of Brittany and in and east the Ardennes, Hunsrück and Vosges. To the south, it borders on the Massif Central and the Morvan. To the north, its strata link into those of the bed of the English Channel and south-eastern England. Other boundaries lie on ridges in less old rocks and scarps such as the Côte d'Or (on an Alpine fault line) and the Hills of Artois which overlie the margin of London-Brabant Island.
See also
References
- Anon. Carte Géologique de la France à l'Échelle du Millionième ISBN 2-7159-2158-6
- Dercourt, J. Géologie et Géodynamique de la France 3rd. edn. (2002) ISBN 2-10-006459-2
Bassin parisien