All shades of green
The crystalline Périgord is one of the margins of the Massif Central. Its marked relief with points between 300 and 400 metres in altitude is associated with slightly more rainfall than the rest of the department. Its flora is characterised by numerous acidic species, with mountain affinities, which in many ways remind us of those predominant in the neighbouring Limousin. Indeed, this Green Périgord is made up of high plateaus, as in Limousin, as many foothills of the nearby Massif Central. It extends from the north to the north-east of the department and is based on primary formations. The general aspect of this region is made of plateaus with slowly undulating ridges, but also narrow, even steep valleys. Let us quote in particular the gorges of Auvézère, river sometimes calm, sometimes capricious, it offers very contrasted faces. You can discover it quietly during a fishing trip and the next day, unleashed. It depends on the seasons and the place where you are. The Auvézère river has its source in the Massif Central, enters the Dordogne and flows into the Isle. It is precisely in the Green Perigord that it is most closely discovered: in Payzac, Savignac-Lédrier, St-Mesmin or Génis. It has shaped unique mountain landscapes in the Dordogne. However, it remains rather unknown, wild, powerful and capable of devastating floods. It has also allowed the industrial development of its basin, with many dams and forges. Finally, this green Périgord is marked by the presence of woods and meadows that give it a bocage appearance. It is the land of choice for the extensive breeding of Limousin cattle.
Dominantly limestone soils
Central Périgord is a vast area of Cretaceous limestone, with large areas of siderolithic veneers (acidic sandy zones). Natural erosion by watercourses has formed a landscape of modest hills (150 to 230 meters) interspersed with valleys. This is the realm of pedunculate oaks and chestnut trees. The land is fairly diversified, allowing for mixed farming in which strawberries have played an important role for several years now. The Ribéracois terroir is very similar, though punctuated by small causses (Mareuil and Paussac). It's a low-lying plateau, ideal for cereals, but also for cattle breeding, thanks to the meadows in its small valleys. Fattened poultry production has recently developed in this area. The Sarladais, on the other hand, consists of a vast Cretaceous limestone plateau 250 to 350 m high. The very powerful erosion of the Dordogne and Vézère rivers has created a landscape of great topographical variability: cliffs, meanders (cingles), hills, valleys and combes create a great microclimatic diversity, and consequently a wide variety of species. Some areas are almost Mediterranean in character. The valleys are cooler and shadier. This mosaic of environmental conditions has had an impact on the way people have used the land: corn in the valleys, walnut and chestnut trees on the plateaus, and truffle oaks. The causses are areas of compact Jurassic limestone, a continuation of the Quercy limestone. These are alternating plateaus of arid hills and rare watercourses. The Périgord causses are usually divided into four sub-areas: causses de Cubjac-Thenon, coteaux du Terrassonnais, Terrasson-Nadaillac and Daglan. Finally, the Bergeracois, along the lower Dordogne valley, is distinct from the other limestone terroirs of the department. It is composed of a substratum formed of Tertiary detrital deposits, predominantly limestone. It is a vast plateau with limestone outcrops and mollassic formations of the Terrefort du Dropt, bordered to the north by the Dordogne valley. It's a land of choice for vineyards, with large areas in the southern part devoted to cereals.
The largest towns in the department are located in this Périgord limestone bedrock. It has favored human settlement, urban development, buildings and infrastructure, thanks to the use of stone as the main building material. This limestone Périgord, with its relatively accessible relief and wide valleys, benefits from a large number of transport routes, unlike the north of the department, which is still quite isolated. The limestone bedrock has also enabled the development of a lime industry (Saint-Astier).
The exceptions of the Double and the Landais
Located in the west of the département, on either side of the Isle valley, these two areas are characterized by a moderate relief, covered by an acidic sandy-clay substrate. This is the spontaneous sector of the Tauzin oak, to which man has added numerous plantations of maritime pine. As a result, the flora here takes on Atlantic accents, reminiscent of the Landes de Gascogne, for example. Above all, La Double boasts an extensive hydrographic network, which has led to the development of a flora specific to wetlands. La Double is an exceptional terroir, resting on the sands and clays of Périgord. It's a vast wooded plateau, with an impermeable subsoil dotted with ponds. Fish farming, forestry and livestock breeding are the dominant forms of production. For a long time, it was a landlocked peasant region, where the Doublaud people suffered from malaria and great hardship. Wolves were present in its deep forest in their natural state until 1914. It's also a land of legends and superstitions. The Landais is the extension of the Double to the south of the Isle valley, with its vine-covered hillsides heralding the vineyards of the southern Bergerac region. In conclusion, you will note that Périgord is not a territory with clearly defined borders. Rather, its division is the result of political and administrative will, so much so that the landscapes of neighboring départements are highly porous.
