Compound-specific carbon isotope analysis of short-chain fatty acids from Pine tissues: characterizing paleo-fire residues and plant exudates

Microstratigraphic, lipid biomarker and stable isotope study of a middle Palaeolithic combustion feature from Axlor, Spain

Archaeological research has increasingly focused on studying combustion features as valuable sources of information regarding past technological and cultural aspects. The use of microstratigraphic and biomolecular techniques enables the identification of combustion residues and substrate components, and infer about past fire-related activities and the environments. Our study conducted on a combustion feature (Level N, ∼100 Ka) at the Axlor cave, a Middle Paleolithic site in northern Iberia, exemplifies the interdisciplinary approach to combustion features. Micromorphological features revealed depositional activities associated with occupations such as hearth rake-out and trampling. Through molecular (n-alkanes, n-alcohols, and n-fatty acids) and isotopic analysis (δ13C16:0 and δ13C18:0), we infer the good preservation of organic matter, the contributions of non-ruminant fats, and the dead-wood gathering strategies by Neanderthal groups. By combining microstratigraphic and biomolecular approaches, our study significantly contributes to the advancement of our current understanding of Neanderthal pyrotechnology.