Stable carbon and oxygen isotopic compositions of wood ash: an experimental study with archaeological implications

► Stable isotope compositions of carbon and oxygen studied in experimental wood ash. ► Method enables differentiating low and high temperatures of wood ash formation. ► Method enables differentiating wood ash formed from C3 and C4 vegetation types. ► A mixing line of isotopic compositions occurs in ash formed between 500 and 900 °C. ► Isotopic compositions elucidate diagenesis of wood ash in archaeological sites.