Abstract: Preserved ash in the archaeological record constitutes an important source of information on the manner in which fire was used by hominids. Recognizing fossil ash deposits is difficult, because ash is not stable in most environments, but undergoes a series of diagenetic alterations. Here we review the mineralogical transformations that ash deposits underwent in two caves in Israel. We note that a relatively stable component of ash, at least in these environments, is the siliceous aggregate fraction. Its presence in bedded layers within the stratigraphic sequence at other sites may constitute good evidence for the presence of fossil ash deposits.

Key words: Fire; Ash; Minerals; Infrared spectroscopy; Diagenesis