Resumen de Depositional and post-depositional processes in rock shelters of Northern Italy during the Late Pleistocene. Their paleoclimatic and paleoenvironmental significance
- English
The fill of seven rock shelters and caves (Riparo di Fumane, Grotta della Ghiacciaia, Riparo Mezzena, Riparo Tagliente. Grotta della Paina, Grotta di S. Bernardino and Grotta del Broion) located in the Veneto Region (Northern Italy) have been studied by means of geo-pedological techniques. The stratigraphie sequences have been dated and correlated by means of radiocarbon dating and archeo- logical evidence included into the fills. Pollen analyses and mammal fauna provide an independent source of information to test the reliability of the geo-pedological techniques for the paleoenvironmental reconstruction. The sedimentation and weathering of the deposit have been controlled by environmental factors and reflect several steps of climatic changes during glacial stages of the Late Pleistocene. Three pedo-sedimentary cycles have been distinguished : the first one is composed of colluvia intercalated by weakly developed soil horizons and has been originated in a wet and moderatly cold climate. The second one is composed of colluvial soil-sediments, thermoclastic breccia, loess, and soil horizons which represent successive climatic phases of a same cycle ranging respectively from a wet cold, wet very cold, dry cold climate to a temperate climate. The third one, while rarely well preserved, includes the same lithostratigraphic units of the previous one and it represents a succesive glacial cycle. On the basis of the stratigraphie relationships of the lithic assemblages and of some radiocarbon datings, the first cycle is dated back to the beginning of the Wiirm glacial period and tentatively correlated to the stage S a-d of the isotopic record, the second cycle is correlated to the isotopic stages 3-4 and should represent the first pleniglacial period of the Late Pleistocene; the third cycle, correlated to stage 2, represents the second pleniglacial period.
- français
Les remplissages de sept abris-sous-roche et grottes (Riparo di Fumane, Grotta della Ghiacciaia, Riparo Mezzena, Riparo Tagliente, Grotta della Paina, Grotta di S. Bernardino e Grotta del Broion), qui se trouvent en Vénétie (Italie du Nord) ont été étudiés à l'aide de techniques géo-pédologiques. Les successions stratigraphiques ont été datées et corrélées grâce a des datations au radiocarbone et au contexte archéologique. De plus, l'étude des pollens et des micromammifères fournit une source indépendante d'informations pour vérifier la signification paléoenvironmentale des données géo-pédologiques. La sédimentation et l'altération pédologique des remplissages sont surtout déterminées par les changements climatiques qui se sont déroulés pendant les phases glaciaires du Pléistocene supérieur. Trois cycles pédo-sédimentaires ont été reconnus : le premier se compose de sédiments colluviaux interstratifiés aux horizons pédologiques faiblement développés. Cet ensemble s'est déposé dans un contexte climatique frais et humide. Le second se compose de sédiments de sols colluvionnés, brèches thermoclastiques, loess et horizons pédologiques, chacun représentant une phase climatique d'un même cycle glaciaire, respectivement froid-humide, très froid et moderatement humide, froid-aride et tempéré-humide. Le troisième répète la même succession lithostratigraphique du second et représente le cycle glaciaire suivant.
