A new method of chronological and geometrical analysis is used for understanding the sedimentary and tectonic evolution of perisutural basins (foredeep and foreland basins). It may be applied to synorogenic basins whose infilling was controlled by sea-level fluctuations and where, as a result, the tectonic structures are well preserved. This method is based on the mapping of depositional sequence boundaries and maximum flooding surfaces defined by sequence stratigraphy. These planar markers are considered as synchronous and their numerical ages are determined by classical chronostratigraphic methods, by dating and by comparison with the eustatic global cycle chart.The evolution of the studied perisutural basins is controlled by the propagation in space and time of a syn-depositional thrust-and-fold system including a faultpropagation anticline and two synclines (a foreland and a hinterland syncline) over and in front of a blind basal sole thrust. The propagation of this thrust-andfold system toward the foreland is connected to unconformable depositional sequence sets, which indicate for each system a time span for thrusting of several eustatic cycles.The evolution of a single thrust-and-fold system corresponds to a shortening accommodated by upward imbrication of second-order thrusts inside the anticline. Each of these thrusts is related, at least, to one depositional sequence lying unconformably on the external side of the fold and deformed by the successive development of the branch lines toward the hinterland. This tectono-sedimentary correlation indicates a time span sometimes as short as one eustatic cycle for each second-order thrust.Thrusting and sea-level changes are not exactly synchronous, as the depositional sequence sets (which are tectonic in origin) do not systematically correlate with eustatic supercycles. The apparent time correlation between the two groups of independent phenomena is an artefact of the method which calibrates the tectonic evolution by comparison with eustatic fluctuations.Applied to the South Central Pyrenees, the method has specified the structure of the Late Cretaceous foredeep basin and has revealed the successive stages of forward thrust-and-fold system migration (4 to 5 Ma for each one from 89 Ma) and of hindward second-order thrust migration (1 to 4 Ma for each one).In the North Central Pyrenees as in the South Central Pyrenees, Late Cretaceous foredeeps are characterized by syntectonic turbidite deposits (from 89 Ma at ECU Libraries on July 7, 2015 http://sp.lyellcollection.org/ Downloaded from

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Late Jurassic platform carbonates of Languedoc (southern France) are deeply incised by Late Miocene canyons, allowing the observation of karst systems filled with sediments containing evidences of marine origin. Field and structural relationships as well as new biostratigraphic data (planktonic foraminifera and calcareous nannofossils) provide a Latest Cretaceous-Earliest Paleocene age for the major karstification and a Paleocene (Danian-Selandian) age for the sedimentary filling. The Ն 350 m vertical extent of this karst system and its subsequent marine filling gives a minimum amplitude for the base-level variation responsible for the karstification and then the marine flooding events. The observations suggest that at least, two marine successive events occurred in the Late Danian then in Selandian time. The large amplitude of base level is not in agreement with eustatic sea-level change, and the rate of base-level change is too fast for tectonic uplift and subsidence within the tabular, poorly deformed studied area. We propose a model of a silled endoreic basin, which was dessiccated and karstified over hundreds of meters, when it was disconnected from the World Ocean, and later suddently transgressed by the Paleocene sea and the karst flooded, when the bounding sill was submerged. Such a model is similar, although with significant differences, with the later Messinian-Zanclean event that affected the Mediterranean realm. Remplissages marins karstiques : évidence de variations extrêmes du niveau de base et conséquences géodynamiques (Paléocène du Languedoc, sud de la France)Mots-clés. -Paléokarsts, Niveau de base, Paléocène, Bassin endoréique.Résumé. -La plate-forme carbonatée d'âge jurassique supérieur du Languedoc (sud de la France) est profondément incisée au Miocène par des canyons, permettant ainsi d'observer un système karstique développé sur toute l'épaisseur du massif, contenant des sédiments internes d'origine marine. Les relations structurales de terrain ainsi que de nouvelle données biostratigraphiques, comme les foraminifères planctoniques et notamment des déterminations sur nannofossiles calcaires, révèlent un âge crétacé terminal à paléocène précoce pour la phase majeure de karstification et un âge paléo-cène (Danien-Sélandien) pour un remplissage des cavités. Le développement vertical de ce système karstique sur plus de 350 m et les remplissages sédimentaires marins qui ont suivi, contraignent une valeur minimum de l'amplitude de variation du niveau de base, responsable de la karstification, puis de l'ennoiement marin. Nos observations indiquent l'existence d'au moins deux phases successives d'ennoiement marin, au Danien supérieur puis au Sélandien. La grande amplitude de variation du niveau de base est excessive pour des variations eustatiques. De plus, la vitesse de variation semble trop élevée pour des surrections et des subsidences dans cette zone peu déformée et tabulaire. Nous proposons un modèle de bassin endoréique à seuil, soumis à assèchement et karstification sur plusieurs centaines de...