The chalkstone as medieval construction stone in Normandy, France
- D. Ballesteros 1
- A. Painchault 2
- B. Puente-Berdasco 3
- C. Nehme 1
- E. Pons-Branchu 4
- B. Roussel 1
- F. Delisle 2
- D. Todisco 1
- J.I. García-Alonso 3
- M. Vanaro 2
- D. Mouralis 1
- 1 Université of Rouen-Normandie / CNRS
- 2 Université de Rouen-Normandie
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3
Universidad de Oviedo
info
- 4 Université́ de Paris-Saclay
ISSN: 1576-5172
Year of publication: 2021
Issue Title: X Congreso Geológico de España
Issue: 18
Pages: 870
Type: Article
More publications in: Geotemas (Madrid)
Abstract
The chalk is a coccolithic biomocritic limestone Upper Cretaceous in age used for building in western central Europe since the Antiquity. The project ATP (archaeomaterials, territory and patrimony) aims to characterize geologically the chalkstone, their uses and quarries involved in 22 medieval buildings (cathedrals, abbeys, churches, palaces and castles) constructed during the 9-14th centuries. The geological characterization includes the microscopic, geochemical (ICP-MS, ICP-EOS) and isotopic (87Sr/ 86 Sr via MC-ICP-MS) analysis of stones from buildings and quarries. This data was also complemented by 3D modelling of quarries (DistoX, Terrestrial Laser Scan), by stratigraphy analyses of the chalky bedrock, and geochro- nology (AMS14 C, U/Th) on speleothems precipitated on exploitation benches. Results show that the Normand chalkstone were used for the funding and walling of medieval buildings, as construction material of openings (windows and others) and indoor works (stairs, figures...). Five varieties of chalkstone were used, highlighting the dolomitized chalkstone in the Seine valley, the glauconitic-silicified variety quarried in the Eastern Normandy Coast, and the calcarenitic employed in the SW of the Eastern Normandy. Chalkstones were supplied by underground quarries with up to 1.4 Mm3 volume, located at 3-50 km away from the buildings. Radiocarbon and U/Th datings suggest that one of these quarries was active during the High Medieval Ages.