Domestic activities at Las eras del Alcázar (Úbeda-Jaén, Southern Iberia) through phytolith and calcitic microfossil evidence

The archaeological site of Las Eras del Alcázar is situated in Úbeda (Jaén) and its chronological sequence spans from the second quarter of the 4th millennium BC to the first quarter of the 2nd millennium BC. This study aims to present the findings obtained from integrated microfossil analyses, including phytoliths, calcitic plant and faecal microremains, from a Bronze Age dwelling displaying three well-defined stony floor sequences and a hearth from sector 16. The phytolith assemblages were in general well-preserved. Elongated dendritic phytoliths and epidermal appendages, often considered fragile morphologies, were frequently observed in the samples. The phytolith assemblages were dominated by grass silica short cells produced from the Pooideae subfamily, which includes cereals such as wheat (Triticum sp.) and barley (Hordeum sp.), species found at the site in macrobotanical records. Of particular note is the presence of echinate spheroid phytoliths, characteristic of palms (Arecaceae), likely from Chamaerops humilis, which is native to Mediterranean regions. This is significant as these fragile plant remains are largely absent from macrobotanical assemblages. In addition to phytoliths, calcitic wood ash pseudomorphs, morphologically resembling those produced by the Quercus genus were also recorded, which could relate to the use of these plants for fuel, among other purposes. Overall, these findings provide a more comprehensive understanding of plant use and domestic activities within Argaric households from a diachronic perspective.