ESR INVESTIGATIONS OF BURNT SOIL

Electron spin resonance (ESR) of transition metal ions (Mn2+, Fe3+), r adiation induced centres and pyrolytically formed radicals was studied to distinguish between burnt and unburnt soil. A testfire place and s amples from an archaeological site were analyzed. The concentration of radiation induced centres decreases and pyrolytically formed radicals appear in a thermal annealing experiment. The spectral pattern of iro n and manganese resonances changes during the heating process. These s ignals are useful to estimate temperature and atmosphere of the heatin g event. Chemithermoluminescence (CTL) of the soil was studied and cou ld reveal its thermal history, too.