S Loboziak

Miospores in middle-upper Frasnian to Famennian sediments partly dated by conodonts (Boulonnais, France)

Abstract The middle-upper part of the Formation de Beaulieu exposed in the new railroad trench at Caffiers-Ferques and the Formation de Ferques exposed in the Tartinskal quarries contain well-preserved miospore assemblages. They are here restudied in comparison with new conodont data ranging from the middle asymmeyricus to the Ancyrognathus triangularis Zone. The conodonts allow precise correlations with the type Frasnian area as well as with the Russian Platform and Timan-Pechora provinces. The miospore assemblages of the Formation dHydrequent are also considered and their age discussed in term of the Frasnian/Famennian boundary. In the systematic part, two new combinations are proposed: Ancyrospora lysii (Taugourdeau-Lantz, 1960) nov. comb., and Pustulatisporites rugulatus (Taugourdeau-Lantz, 1967) nov. comb.

Miospores in givetian to lower frasnian sediments dated by conodonts from the Boulonnais, France

Abstract The Calcaire de Blacourt and the lower part of the Schistes de Beaulieu exposed in the new railroad trench Caffiers-Ferques and in the Griset Quarry (Boulonnais, France) contain well-preserved miospore assemblages which have been previously described from continental beds in Scotland, Spitsbergen and the Canadian Arctic Islands. Their distribution is presented in relation to a conodont zonation, ranging from the Icriodus obliquimarginatus Zone to the lower Polygnathus asymmetricus Zone, and allows accurate correlations with the type sections of Givet and Frasnes in Belgium where several optimal horizons could be selected to fix the Givetian/Frasnian (Middle-Upper Devonian) boundary.