Bulletin de l'Association française pour l'étude du quaternaire - Année 1989 - Volume 26 - Numéro 2 - Pages 65-71L'étude des forages, des gravières et la datation par le radiocarbone de 17 bois enfouis dans les sédiments de la plaine du Pô, au sud de Turin, ont permis de définir plusieurs unités sédimentologiques. Sur cette base un modèle d'évolution de la plaine padane au cours de l'Holocène est proposé. By detailed investigations on fluvial sediment exposures, analysis of core samples, I4C dating in the Po river floodplain upstream Tonno (NW Italy) Upper Pleistocene and Holocene fluvial sequences have been recognized and described. The Pleistocene-Holocene boundary is always sharply evidenced by an erosional surface incised on a peat-beanng clayey silt from Middle-Upper Pleniglacial; this marker honzon is widespread under terraces bordenng Po nver. In the reach in study, Holocene sediments, made by gravel in the lowest two thirds of the senes, then by loamy sands, arc condensed in a thickness of 6-8 m. Subfossil logs, widespread at different dephts, revealed a 14C age generally ranging from c 6 000 yrs. B.P. to Modem. The resulting sedimentation rates appear comprised between 0 5 and 5 mm year1. Several changes occurred in fluvial pattern since Upper Pleistocene up today. 7 pages Source : Persée ; Ministère de la jeunesse, de l’éducation nationale et de la recherche, Direction de l’enseignement supérieur, Sous-direction des bibliothèques et de la documentation.