CEVENNES, a mountain range of southern France, forming the south and east fringe of the Plateau Central and part of the watershed between Atlantic and Mediterranean basins. It consists of a narrow ridge some 32o m. long, with numerous lofty plateaux and secondary ranges branching from it. The northern division, nowhere over 3,32o ft., is called the mountains of Charollais, Beau jolais and Lyonnais, from the Col de Longpendu (west of Chalon sur-Saone) in a southerly direction to the Col de Gier. The cen tral Cevennes, comprising the volcanic chain of Vivarais, incline south-west and extend as far as the Lozere group. The northern portion of this chain forms the Boutieres range. Farther south it includes the Gerbier des Joncs (5,089 ft.), the Mont de Mezenc (5,755 ft.), the culminating point of the entire range, and the Tanargue group. South of Mont Lozere, where the Pic Finiels reaches ft., lies the range strictly called the Cevennes. This region stretches south to include the Aigoual and Esperou groups. Under various local names (the Garrigues, the mountains of Espi nouse and Lacaune) and with numerous offshoots, the range ex tends south-west and then west to the Montagne Noire. In the south, the Cevennes separate the barren region of the Causses from sunny Languedoc, where olive, vine and mulberry flourish. Northwards the contrast between the two slopes is less striking.
The Cevennes proper are a folded belt of Palaeozoic rocks along the south-east border of the central plateau of France. Concealed in part by later deposits, these folds extend from Castelnaudary to near Valence, where they sink suddenly beneath the Tertiary and recent deposits of the Rhone valley. Rocks from Cambrian to Carboniferous are included in the folded belt, and the gneiss and schist which form so much of the chain consist, in part at least, of metamorphosed Cambrian beds. The structure is complicated by extensive overthrusting from the south-east. The principal folding is of Hercynian age. Permian and later beds lie uncon formably upon the denuded folds, and in the space between the Montagne Noire and the Cevennes proper the folded belt is buried beneath the horizontal Jurassic strata of the Causses. Folding was renewed along the south-east margin at the close of the Eocene period. The Secondary and Tertiary beds of Languedoc were crushed against the central plateau and were frequently over folded, but the ancient Palaeozoic chain acted as part of the un yielding massif, and the folding did not extend beyond its foot.
The Cevennes form the watershed between the basins of the Loire and the Garonne to the west and those of the Saone and Rhone to the east. In the south the Orb, the Herault and the Vidourle flow directly into the Gulf of Lyons; farther north, the Gard, the Ceze and the Ardeche flow to the Rhone. The Vivarais mountains and the northern Cevennes approach the right banks of the Rhone and Saone closely, and short torrents flow down to those rivers; on the west side the streams are tributaries of the Loire, which rises at the foot of Mont Mezenc. A short distance to the south on the same side are the sources of the Allier and Lot. The waters of the north-western slope of the southern Cevennes drain into the Tarn. In the Lozere group and the southern Ce vennes generally, is good summer pasturage for huge flocks. Silk worm-rearing and the cultivation of peaches, chestnuts and other fruits are also carried on. In the Vivarais cattle are reared, while on the slopes of the Beaujolais are flourishing vineyards.