AVEYRON, a department of the south part of the Massif Central, in south France, stretching from the Cevennes across the wild Causse noir, the Causse Ste. Affrique and the plateau of Larzac to include portions of the valleys of Tarn, Aveyron and Lot on the west side of the massif. It is bounded on the north by Cantal, east by Lozere, south-east by Gard and Herault, south west by Tarn, and west by Tarn-et-Garonne and Lot. Area 3,386 sq. miles. Pop. (1931) 323,782, a heavy decline since igo6.
Aveyron is specially rich in dolmens, evidencing a culture in this locality now increasingly attributed to the early ages of metal. Statue-menhirs are a feature of the culture, as are small metal beads. Vidal de la Blache thinks this culture flourished before the covering of woods, etc., was destroyed, as, since then, the high land of this department has become desert with bare limestone surfaces, sometimes in a chaos of blocks simulating a ruin, as at Montpellier-le-vieux on the Causse noir. The rivers make deep and beautiful gorges and valleys in the highland plateau much of which is well above the 2,000f t. level. The department verges on the volcanic country of Auvergne, and the volcanic mountains of Aubrac on the north-east boundary reach a height of 4,760 feet.
Aveyron has a rigorous climate -in the highlands but condi tions are mild in the sheltered valleys of the lower lands. The average annual rainfall oscillates about 800mm., but is far higher on the mountains of Aubrac. The mean temperature for winter (reduced to sea level) is about 41° but the actuality varies a great deal. The usual crops are grown on the poor soil, potatoes, some wheat, rye and oats, and so on, but vineyards occur in shelter as at Entraygues, S. Georges, Bouillac and Najac, and chestnuts in the south, between Aveyron and Tarn. Walnuts, plums, apples for cider and mulberries for silkworms are also grown to some extent. The main occupation is, however, that of keeping live stock cattle of the Aubrac breed, and sheep on the Larzac plateau, the latter supplying milk for the famous Roque fort cheeses ripened in caves near the town.
The west of the department is largely formed of archaean rocks, but a long basin of carboniferous and later rocks spreads westward with the carboniferous rocks exposed towards its west ern end and along the flanks. At the west end coal is worked near Aubin (pop. 1931, 4,378) and Decazeville; at the former surface coal has been in use since the 9th century, the latter is a new industrial town (pop. 1931, 12,426) with iron foundries and is named after the Duc Decazes who founded them in 183o. Coal is also dug near Rodez, and iron is mined in the department, also lead and zinc. Millau is another industrial centre (pop. 1931, 14,722) making gloves as a speciality. Wool weaving and a num ber of minor industries are maintained and there is a good deal of quarrying.
Rodez, the capital, Millau and Villefranche-de-Rouergue give their names to the three arrondissements into which the depart ment is now divided. The department is a bishopric, with bishop's seat at Rodez, under the archbishop of Albi ; it belongs to the i6th military region and to the academic or educational district of Toulouse, its court of appeal is Montpellier. It is served by the Orleans and the Midi railways.
The department corresponds nearly to the ancient Rouergue, the countship of which was united to that of Toulouse in the century. Some "bastides" were founded in the 13th century and Villefranche and Sauveterre are good examples. Of monastic foundations, Conques in the north is one of the most famous in France, with a magnificent Romanesque abbey church containing a rich reliquary. Espalion, Najac and Sylvanes also have interest ing mediaeval castles and churches.