Combustion and cooking areas at El Edén archaeological site, Upano Valley, Ecuador—650 BP

Identifying areas of domestic activity in pre-Hispanic Amazonian contexts poses methodological challenges due to sedimentary dynamics and limited organic preservation. This study examines the Upano River valley during the Huapula phase (1305–1405 AD), focusing on combustion- and cooking-related contexts at the El Edén archaeological site through archaeological excavation, supported by XRF geochemical analysis and phytolith studies. Six sediment samples from floors and hearths were analysed. Geochemical results show a matrix dominated by SiO₂, Al₂O₃ and Fe₂O₃, with variations in CaO, K₂O, P₂O₅, TiO₂ and ZnO reflecting feature-specific functional differences. Cluster analysis identified two compositional groups linked to hearths and domestic floors. Phytoliths provide evidence of cultivated plants, including maize, cassava and palm species used for food production and construction. The integration of geochemical and microbotanical evidence supports interpretation of combustion-related activities and floor use, highlighting the exploratory potential of these methods for understanding domestic practices in pre-Hispanic Amazonian contexts.