Dynamique holocène de la végétation et occupation des Pyrénées andorranes depuis le Néolithique ancien, d'après l'analyse pollinique de la tourbière de Bosc dels Estanyons (2180 m, Vall del Madriu, Andorre)

The Cova dels Xaragalls is a small open karst system, located in the municipality of Vimbodí-Poblet (Tarragona, Catalonia, NE Spain). It is an important Holocene archaeological site that was inspected in the 1970s but from which little has been published. New excavations starting in 2008 have exposed a deep Late Pleistocene stratigraphical sequence. In this paper, we present for the first time palaeoenvironmental and palaeoclimatic reconstructions of this Late Pleistocene succession on the basis of both the small-vertebrate assemblages and the charcoals. Results from the small-vertebrate associations along the sequence indicate that the landscape had open-woodland habitats in the vicinity of the Cova del Xaragalls, with wet points in the surrounding area. Woodland habitats were dominant throughout the sequence, as evidenced by the abundance of the species Apodemus sylvaticus, but were better developed during warm periods (layers C5 and C8), whereas during cold periods (layers C4 and C3) the environment was slightly more humid in response to higher mean annual precipitation and the opening of the landscape. The charcoal analysis indicates that the woodland surrounding the cave was composed mainly of Pinus (more than 90% was identified as Pinus), but that during the cold period (C3-C4) it incorporated some Quercus ilex/coccifera and Angiosperm indet., probably linked with greater precipitation. Comparisons are made with other long palaeoenvironmental sequences from the northeastern Iberian Peninsula and with global marine isotopic curves, providing a scenario for the palaeoclimatic and palaeoenvironmental changes that occurred during the Late Pleistocene in the woodland areas surrounding the Cova dels Xaragalls. MANUSCRIT ACCEPTAT3

El Mirador site has a sequence formed by burnt dung resulting from pastoral activities during the Bronze Age and the Neolithic period. Because there is a high sediment variation in the profile, facies descriptions were used to guide the archaeologists in their work. Paleobotanical and mineralogical analyses were used to describe and understand the formation of the facies from the MIR 4 level. Furthermore, the paleobotanical results serve to reconstruct the landscape in Atapuerca during the Bronze Age. Most seeds recovered are from Triticum aestivum/durum, but other cereals and also Leguminoseae and fruits have been identified. Charcoal analysis has yielded mainly deciduous and evergreen Quercus. Pollen analysis has revealed a low arboreal cover, with Pinus, Quercus and riverside trees. Most of the pollen record corresponds to herbs, such as Poaceae and Asteraceae. All these results indicate a mosaic of different biota with forest, pastureland and cultivated fields near the site. Most of the phytoliths come from the leaves and stems of festucoid grasses. However, there are some differences in the phytolith type and number, the amount of faecal spherulites, the mineralogical composition and the percentage of multicellular structures that indicate that not all the facies in the site have been formed in the same way. Thus, the work carried out has demonstrated that some facies are related more to agricultural activities than to pastoralism activities, and that other facies have been affected by incipient diagenetic processes.

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