Formation processes through archaeobotanical remains: The case of the Bronze Age levels in El Mirador cave, Sierra de Atapuerca, Spain

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