Sand and Gravel

There are significant deposits of sandstone, sand and gravel throughout the Touraine Loire Valley and adjoining areas. Some are clearly associated with the big rivers, especially the Loire itself, which forms islands and banks of sand and gravel. Others are the product of the weathering of geological features known locally as puys, limestone ridges which originally had sandstone caps, such as can be found around Chinon. Much of the Sologne is sandy soil. Many of the buildings around the Maison du Parc in the Brenne are made of local sandstone.

Sand extraction near Rilly sur Vienne. The photograph is taken from on top of the limestone ridge that would once have been capped by sandstone which has now broken up and migrated down the slope to form sand beds at the base.
Sand pits such as these, especially once they have been worked out and abandoned, can provide habitat for certain species of dragonfly eg Western Clubtail Gomphus pulchellus, which likes still water with not too much vegetation. In some places Bee-eaters Merops apiaster use the sides of sand and gravel pits to dig nest holes.

Grey Hair Grass Corynephorus canescens growing amongst Cladonia lichen on dry sandy soil adjacent to the Loire River in the VĂ©ron (the triangle of land at the confluence of the Vienne and the Loire). This type of grassland habitat is known as a 'grey dune' and despite the impoverished nature of the soil, the habitat is rich in biodiversity, particularly insects. Traditionally this type of grassland' was managed as common land and used for grazing. Nowadays it is mowed to maintain the balance of plants.

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