The Causse de Canayère plateau

7 points of interest

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  History

  Canayère

  A former farm turned forester's house in 1880. In the early days of the Mont Aiguoal reforestation, forestry officers lived here year-round during their missions. Forestry workers working on the replanting were allowed to use the outbuildings. Later, only one official resided here. Since 1967, no official has permanently lived here. (B. Mathieu)

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  History

  A recent forest

  The stands that were planted during the large reforestation programmes of the late 19th century onwards consist of black pines, a rustic species that is well-adapted to dry limestone soils. Underground, the Causses plateaux are characterised by networks of tunnels and cavities that have been created by water movement over millions of years. Subterranean rivers are blocked by the impermeable layers of the valley floor and flow into the Trévezel instead.

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  Natural environment

  Typical grasslands on limestone soil

  This small area of grassland is one of the rare open spaces on the Causse de Canayère. It is of interest for the preservation of certain flower species, especially the pasqueflower and several varieties of orchid. To counteract the natural progression towards more closed environments, this site is maintained by regular mowing.

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  Geology

  Open-sky geology

  The granite and schist (slate) that constitute the bedrock of the Cévennes and Causses were created in the Paleozoic. The bedrock was then flattened by erosion and covered by the sea, leading to limestone deposits. On the reliefs, erosion has eliminated the sedimentary top layer while in zones of subsidence, such as the Causses, the limestone deposits remained in place. Since then, waterways have cut ever deeper into the limestone, and continue to do so today.

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  History

  The hamlet of Espruniers

  This hamlet, which consisted of a sizeable grouping of houses, was inhabited until about 1930. You have stopped on what was probably the threshing floor for grains.

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  Geology

  The schist/limestone contact zone

  Here, the layers of the schist outcrops are almost vertical in places. This contact between Causses and Cévennes, between the primary bedrock and the limestone layers, is due to a geological fault created by the various movements and constraints that have affected the Earth’s crust. In this zone, the schist bedrock has been pushed upwards by several hundred metres along the fault line compared to the limestone plateau, although the latter is less old.

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  Flora

  Calcifugous vegetation

  This section of the path in the schist zone showcases calcifugous (“limestone-avoiding”) vegetation, which only grows on acid soils (schist or granite): especially chestnut trees, ferns, heather and broom.