habitat rupestre.pdf - Società Friulana di Archeologia

REDISCOVERY AND ENHANCEMENT OF THE INHABITED BUT FRAGILE CAVE-DWELLINGHERITAGE IN THE VAL DE LOIRE: TURQUANTM. C. MénardEcole Nationale Supérieure d’Architecture de Paris La Villette, France1. General characteristicsTroglodytism (hollowed out or underground architecture) has,since the beginning of humanity, developed in all parts of theworld where geological and topographical conditions havemade it possible. This highly specific occupation of space has,over the centuries, resulted in a highly varied, innovative andunique cultural heritage in various civilisations: places of worship,temples, mosques, churches, housing and workplaces.However, this heritage continues to remain largely unknown,including in the countries where they are to be found. It deservesto be rediscovered, studied, preserved and enhanced.The present research intends to show how it represents a heritageshared all around the Mediterranean Rim.While not being one of the main troglodytic countries, Francenevertheless has a large number of regions where this phenomenonhas developed since prehistory and there are currentlyaround 5,000 troglodytic dwellings in France. This study particularlyconcentrates on the Val de Loire region where thislifestyle remains active and is even undergoing a certain resurgence.More specifically, we shall study the town of Turquantin the Maine et Loire which, since 1995, has engaged ina policy of saving and rehabilitating its troglodytic heritage byencouraging an economic recovery through the involvementof arts and crafts. The hope is that this operation can becomea pilot model on an international level to safeguard this poorlyunderstood and fragile heritage.We begin by explaining the geological and topographical conditionspermitting the development of this habitat and the varioustypes of troglodytism to be found in this region.The lifestyles corresponding to troglodytism have often beenabandoned and even forgotten, but in certain parts of theworld, they remain living and have adapted to new economicconditions. They can even represent an asset in the economicrecovery of these regions.Fig. 1 France troglodytisme.Fig. 2 Cave tourism map in Anjou.1332. Geological and topographic specificities of the Val deLoire: the saumur hillsidesMost troglodyte sites in France are to be found in the sedimentaryrock formed in the seas and lakes of the secondary era,during the Upper Cretaceous and, more specifically, the Turonianstage for the Val de Loire. The river Loire and its tributariessubsequently cut through the rock to form valleys withbanks forming the hillsides whose amplitude correspondedto the thickness of the sedimentary layers. It is essentially inthese hills that the various troglodytic sites developed.The Turonian is a layering of differentiated strata over a depthof around a hundred metres: -The soft chalk with some flints at the base of the hill on the leftbank of the river Loire:- The white sandy chalk above is a less soft micaceous chalk, alight and resistant rock that was used as the construction materialthroughout the Val de Loire and contributed to its architecturalidentity. Following centuries of use, there is now onlyone operational quarry in Maine et Loire which essentiallyproduces stone for the restoration of historical monuments inSucy en Bourg.- Yellow sandy chalk, a less chalky rock forming the upperlayer.It is in these strata, especially in the sandy chalk, forming theSaumur range of hills that the extraction quarries developedbetween the 10th and 12th centuries:- On the hillside The extracted rock contributed to the con-volumeRicerca_OK_2012-11-15.indd 133 16/11/2012 15:02:15