Region / Appellation
The Loire Valley
Geological Overview of the Loire Valley
One-hundred million years ago, during the Upper Cretaceous Period, much of the Loire Valley was under the ancient seas of the Paris Basin. It was in this prehistoric era, known as the Turonian, that the chalk layers of Anjou (in the middle Loire) were deposited. Tuffeau, as the rock is properly called, is chalky limestone composed chiefly of compressed fragments of Bryozoa — marine organisms which lived in mass-like floating colonies. When exposed to air, the deposits are cemented by iron and magnesium oxides, adding valuable elements to the soil. When mixed with sand and flinty clay from later eras, the tuffeau creates the best vineyards soil. Cabernet Franc grows happily on the Cretaceous chalks of Saumur.
Tuffeau and Troglodyte Dwellings
The Loire Valley is renowned for its grand châteaux overlooking France’s longest river. Many of these châteaux were constructed from tuffeau, the soft yet strong creamy-white limestone quarried for centuries in the Loire region. While royalty and nobility lived in opulent splendor (curtailed by the French Revolution), the limestone quarries provided homes for the general populace. Carved out of cliff faces or tunneled underground, over time the labyrinth of troglodyte caves was converted into dwellings by artists, artisans, monks, farmers and soldiers. During the Norman invasions of the ninth and 10th centuries, the troglodyte caves provided the region with a prodigious underground defense system and escape routes.
The greatest concentration of troglodytes in the Loire Valley is in the region of Saumur. There, whole villages are composed of these unique troglodyte dwellings. Their consistently cool temperature and humidity created a perfect environment for wine cellars, used by the local vignerons, and for mushroom beds for the champignons de Paris. At the end of the 19th century, when construction of the Metro in Paris destroyed the mushroom caves under the city, les champignonistes moved into these abandoned caves. In contrast to the Loire’s majestic, often grandiose, chateaux, an economy of scale, practicality, authenticity, ecological consciousness and direct contact with nature characterize the troglodyte dwellings.Download (PDF)