Application of gamma spectrometry for the characterization and influence of the archeological works of an archaeological site

The purpose of this study was the use of gamma spectrometry to characterize the archaeological site of Molina de Aragon, located in the province of Guadalajara in Spain. To do so, a set of samples with different historical influences have been selected. The samples were analyzed by gamma spectrometry with HPGe detectors, and by X-ray fluorescence, to know their chemical composition. The statistical study of the activity concentration of radionuclides from the natural radioactive series, ⁴⁰K and ¹³⁷Cs, was carried out using box-and-whisker plots, cluster analysis and principal component analysis (PCA). Likewise, the in-situ effective dose rates and the ones determined from the activity concentrations obtained by gamma spectrometry were evaluated to verify sampling reproducibility. The results obtained made it possible to classify the areas of Jewish and Christian influence based on the relationships between ²³²Th and ²³⁸U series and the possible influence of the archaeological works carried out in the study area. The least altered areas could also be identified from the activity concentrations of ¹³⁷Cs and ²¹⁰Pb_ex. Activity concentrations and effective dose rates were equivalent to the natural radioactive background of the Iberian Peninsula. PCA showed a correlation between Fe₂O₃, Al₂O₃ y ZrO₂ and the natural radioactive series of thorium and uranium. (author)