France Morphology

By | February 12, 2022

France is a state of central-western Europe ; almost entirely embraces the French geographical region, between the Pyrenees to the S, the most rugged and elevated part of the Alpine chain to the SE, the Rhine valley to the NE and the sea on the other sides: the Atlantic Ocean to the West, the Canal of the Manche to the North and the Mediterranean to S.

The highest peaks of France are mountains of tertiary origin, on which the Quaternary glaciation strongly acted: the Alps form a diaphragm towards the Po Valley, with the highest European peaks (between French Chamonix-Mont-Blanc and Italian Courmayeur, the Mont Blanc massif, 4807 m); the Pyrenees constitute an equal diaphragm towards the Iberian Peninsula but lower (Montes Malditos, 3404 m). The French side of the Pyrenees is very steep; minus that of the Western Alps. Slightly more recent than the Alpine relief, but still high, are the Franco-Swiss Jura ranges to the North of it. The reliefs of the central and northern France are of more remote geologically origin: they were delineated following the orogenetic movements of the late Paleozoic (Hercynian corrugation) and have undergone further settling or sinking movements, so today they show themselves with more gentle and they are generally of modest altitude, divided and far from each other. Among them we can distinguish the Vosges (Ballon de Guebwiller, 1423 m) to the East and further to the North the Ardennes ; to O the Armorican Massif, which forms the peninsula of Brittany and the, and extends to the South of the furrow of the Loire, as far as the Vendée ; Finally, greater than the others, the Massif Central (Puy-de-Sancy, 1886 m), from which descend to the Loire N and O the Garonne. This massif is the most important because at the end of the Tertiary, influenced by the Alpine emergence, it was raised and rejuvenated (its highest edge, the Cévennes, is in fact to the East, and has a very steep slope towards the Rhone valley, while it slopes slowly towards the W), and was then affected by grandiose volcanic phenomena, due to which Auvergne stands out for its typical landscape of puys, extinct volcanoes with the original conical shape.

According to zipcodesexplorer.com, the French region lacks vast and uniform plains, but there are numerous flat stretches that fill the depressions or pits between the Hercinian massifs (Rhenish plain of Alsace ; Rhône plain downstream of Lyon). Frequent and wider are the areas of gentle and slight undulation, formed by sedimentary layers of secondary and tertiary age deposited in inland seas or lake depressions of the Hercynian relief (basins of Paris and Aquitaine).

The fundamental features of today’s French relief were already established, therefore, at the end of the Tertiary, and the Quaternary brought only superficial or marginal variations. The progress of erosion, alternating with periods of deposition along the main rivers, gave rise to the formation of terraces, especially in the Loire and Seine basins. Fertile silts, sometimes real Löss, covered the infra-mountain plains and the Parisian lowland. On the Alps and the Pyrenees, the hardening of the climate determined the expansion of glaciers, which sculpted the mountain relief (Savoy,, Pyrenees). The Massif Central also had its glaciers, which extended over the volcanic groups of the Cantal and the Monts Dore; other smaller ones covered the Jura (on whose margins the moraine deposits are very visible) and the Vosges (cutting off the free flow to the Moselle several times). Less extensive was the glaciation in the pre-alpine limestone reliefs (southwestern Provence).

Other changes suffered the coastline. The formation of the Calais pass does not seem to be prior to the first glacial periods, and thus the separation between the Norman Islands and the Cotentin. The southern coasts show very different features to the East and W of the Rhone delta: to the East, where the Alps plunge into the Mediterranean with steep slopes, the coast is rocky and rugged by peninsulas and bays, with numerous islands; to the West it is uniform with large lagoons behind coastal strips covered with dunes.

France Morphology