A foreland basin succession has been identified in the Frasnian of the Central Pyrenees. This succession comprises a carbonate-dominated transgressive system which recorded the cratonward migration of the foreland basin subsidence, and siliciclastic depocenters which recorded the progression of the thrust-fold deformation. The foreland basin system has always been maintained in deep-marine environments, i.e., at an underfilled depositional state. It was associated with a thrust wedge which descended toward a deep-marine hinterland, i.e., with a type of orogenic wedge usually related to subduction zones. The Frasnian foreland basin system differs from the one known in the Carboniferous which evolved to overfilled depositional state and was associated with a thrust wedge rising toward a mountainous hinterland. Consequently, the Hercynian orogeny in the Pyrenees seems to result first, from a Frasnian thrusting controlled by a subduction zone located north of the Pyrenees, and second, from a Carboniferous thrusting controlled by the surrection of a frontal thrust belt in the Pyrenees. The association of underfilled foreland basin systems and hinterland-dipping thrust wedges, as exemplified in the Frasnian of the Pyrenees, can be interpreted as illustrative of the initial stages of thrust-wedge growth in deepmarine settings.

The Carboniferous culm of the Pays-de-Sault is divided into two diachronous and synshortening series. These series are dated Late Visean (Pic d'Ourtiset series in a northern overthrust unit) and Early Namurian E2 (La Fajolle series in a southern underthrust unit) from an association of foraminifers, algae, and microproblematica identified in clasts of conglomerates. According to structural positions and facies criteria, these two series are interpreted as two turbiditic depocenters which were generated by southward thrust propagation during Late Visean and Early Namurian. At the scale of the Pyrenean Hercynian range, this evolution is consistent with a thrust and depocenter sequence propagating on the wedge-top depozone of a foreland basin system from the northeast (Mouthoumet subpyrenean massif) to the southwest (end of the High Primary Range) during Late Visean to Westphalian C time interval.

McKinney, F.K, Delvolve, 7.‐J. & Sobieraj, J. 1995 11 30: Conularia sp. from the Pyrénées: further support for scyphozoan affinities of the Conularida. Several specimens of Conularia from the mid‐Carboniferous Culm Formation of the Pyrénées occur as clusters with a large central specimen and several smaller divergent individuals that may be buds from the larger central specimen. Other individual and clustered specimens exhibit complex polygonal cross‐sections that are inferred to have resulted from longitudinal fission of a precursor pyramid into two or more descendant individuals. Apparent budding and transverse fission (strobilation) of conulariids have been reported previously, but we have found no earlier record of longitudinal fission. The existence of this additional mode of asexual increase in conulariids further supports their affinities with the scyphozoan Cnidaria. Conularida, Scypho‐zoa, fission, Carboniferous, Pyrénées.

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