Fuel use in Notheastern Iberia through micromorphology and plant microfossil evidence from Iron Age comustion installations

In this presentation we focus on micromorphological and microfossil evidence from fuel remains from varied types of combustion structures (e.g. flat, semi-excavated and elevated hearths, hearths with and without a preparation layer, ovens) from Iron Age northeastern Iberia. The identification and interpretation of fuel remains through microcontextual thin section micromorphology leads to solid interpretations on key archaeological issues on energy use. Despite in our research area hearth combustion surfaces are found commonly "clean" and macroscopic remains are scarce or even absent, whereas other fire structures appear filled with dumped remains, micromorphological evidence may provide insights into whether or not these remains were burned in situ. In addition to detect depositional pathways, firing episodes and postdepositional processes, microcontextual approaches are critical to assess the integrity of fuel remains, including phytoliths and other calcitic microfossils such wood ash pseudomorphs and dung spherulites, as installation types (e.g. hearths, ovens or walled structures), location (indoor, outdoor), and burial conditions (fast, slow) may determine microfossil preservation. Further, independently of the type of combustion installations and location, the plant microfossil records suggest a varied range of fuel sources, such as wood and a mix of vegetal matter including the leaves and culms of grasses and palm leaves, likely native Mediterranean dwarf palm (Chamaerops humilis) which is common in coastal sites in the research area. Through this integrated micromorphological and microfossil approach depositional pathways and fuel use are identified and understood more accurately, showing the value of microcontextual studies to traditional macroscopic archaeological studies