HIGH‐RESOLUTION (PIXE) ANALYSES OF CARBONATE DEPOSITS IN A ROMAN AQUEDUCT (FRÉJUS,SE FRANCE): IMPLICATIONS FOR THE STUDY OF PALAEOHYDROLOGICAL VARIABILITY AND WATER RESOURCES MANAGEMENT IN SOUTHERN GAUL DURING THE ROMAN PERIOD* |
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| Authors: | C. BOBÉE S. HUON J.‐L. GUENDON J. SALOMON C. GÉBARA J.‐M. MICHEL M. REGERT |
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| Affiliation: | 1. Université Pierre et Marie Curie (UPMC)—UMR 7619 Sisyphe, Case 105, 4, place Jussieu, 75252 Paris cedex 05, France;2. Université Pierre et Marie Curie (UPMC)—UMR 7618 Bioemco, Case 120, 4, place Jussieu, 75252 Paris cedex 05, France;3. Maison Méditerranéenne des Sciences de l'Homme (MMSH)—UMR 6638, BP 647, 5, rue du chateau de l'Horloge, 13094 Aix‐en‐Provence cedex 2, France;4. Centre de Recherche et de Restauration des Musées de France (C2RMF)—UMR 171, Palais du Louvre, Porte des Lions, 14, Quai Fran?ois Mitterrand, 75001 Paris cedex 01, France;5. Service Départemental d'Archéologie, Conseil Général du Var, Le Clos de la Tour, 17, rue Gustave Bret, 83300 Fréjus, France;6. Institut National de Recherches Archéologiques Préventives (INRAP), 561, rue Etienne Lenoir, km delta, 30900 N?mes, France |
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| Abstract: | Urban water was supplied to the Roman city of Forum Julii (Fréjus, southeastern France) for at least 200 years by a 39.4 km long aqueduct, operating in ad 50. Two perennial springs were successively collected, the Foux and the Siagnole, located at the outlet of Triassic and Jurassic karstic reservoirs, respectively. In this study, we performed high‐resolution PIXE (Particle‐Induced X‐ray Emission) measurements of Ca, Si, Fe and Sr concentrations on selected cross‐sections of laminated carbonate sampled along the sidewalls, before and after the connection of the two collection channels. Seasonal variations of water composition, suspended sediment load and discharge are recorded by alternating clear and dark layers, and can be traced by their Sr and Fe contents. On the basis of an annual bimodal high‐discharge regime for the two karstic reservoirs, the concentration measurements allow the derivation of a chronological record (117.5 years) of water supply and maintenance activities for a part of the operational period of the aqueduct. The water level in the channel was mainly controlled by the extent of carbonate deposition and by dredging, repair and maintenance operations rather than by the past hydrological regime of the two springs. |
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| Keywords: | AQUEDUCT FORUM JULII CARBONATE DEPOSITS PIXE ANALYSES WATER RESOURCE MANAGEMENT ROMAN PERIOD |
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