Multi-Method Geophysical Surveys of the Gallo-Roman Site of Brion (Gironde, France): A Small Town in a Wetland

The ancient site of Brion is a small town located on a paleo-island in the marsh of Reysson (Gironde, France). An electromagnetic survey was conducted on an area of more than 50 ha to identify the borderline between island and marsh. The map of electrical conductivity of the ancient island and nearby wetlands revealed the existence of a likely paleo-channel at the north of the town. To the west, it runs along a broad and sloping limestone platform at an altitude close to that of the marsh.