The aeromagnetic map of the French Cadomian belt

In order to obtain an image of the subsurface of the Armorican Massif, two detailed aeromagnetic surveys were combined to obtain an aeromagnetic map a t 350 m altitude with an interpolated grid of 250 m x 250 m. The map shows good correlation between the magnetic anomalies and known geological struct ures and also distinguishes between long- and short-wavelength anomalies. T he long-wavelength anomalies are associated with the overall subsurface arc uate structure of the Cadomian belt. The short-wavelength anomalies are com monly associated with the Lanvollon acid volcanic rocks and syntectonic dio rites, with one set of short-wavelength anomalies in the east of the Saint- Male region being associated with dykes that are exposed onshore and contin ue offshore. (C) 2001 Elsevier Science B.V. All rights reserved.