Site formation processes and settlement reorganisation during the late iron age–roman transition in the eastern Pyrenees: A case study of serrat del castellar (La Cerdanya, Spain)

Despite the growing body of archaeobiological data from Iron Age and Roman sites in the Iberian Peninsula, the interpretative potential of micro-contextual evidence remains insufficiently explored. This study investigates plant use, combustion technologies, and depositional processes at the Late Iron Age and Roman Republican settlement of Serrat del Castellar (Bellver de Cerdanya, eastern Pyrenees), a fortified hilltop site strategically positioned along a major trans -Pyrenean corridor and occupied between the fourth and second centuries BC. An integrated biogeoarchaeological approach combining micromorphology and phytolith analysis is employed to explore construction practices, spatial organisation, and plant management strategies across the Iberian–Roman transition. Microstratigraphic evidence provides high-resolution insights into site formation processes and the evolving biography of the site, while contextual associations of charred plant remains and microscopic residues shed light on food processing, fuel use, and waste management practices within domestic contexts. By examining these micro-scale signatures within their broader stratigraphic and architectural framework, the study contributes to ongoing discussions of continuity and transformation during the Late Iron Age–Roman transition, demonstrating the value of integrated micro-contextual approaches for reconstructing site biographies and everyday practices in high-mountain contexts.