Insights into Gamma-Ray Spectrometry of Building Stones in the North Temple of the Great Ball Court, Archaeological Zone of Chichen Itza, Mexico

Non-destructive tests are especially useful for the assessment of building stones and their deterioration in built cultural heritage. Gamma-ray spectrometry is a non-destructive test that has not been applied extensively in these types of constructions. Therefore, the purpose of this study is to show the results of gamma-ray spectrometry for limestone characterization and deterioration assessment. This study was conducted in the North Temple of the Archaeological Zone of Chichen Itza and several outcrops in the area. Gamma-ray spectrometry data were corrected for attenuation caused by the moisture content in rocks to calculate the real radioelements concentrations using linear regression, with interpretation based on their mobility resulting from chemical weathering processes. The results obtained with gamma-ray spectrometry were corroborated by laboratory analyses, demonstrating that stones from the North Temple are more weathered than rocks from the outcrops, and that some limestones have clasts derived from terrigenous sources, causing them to show slightly higher radiation, which can be distinguished easily with gamma-ray spectrometry, even when lithology cannot be recognized in plain sight. Gamma-ray spectrometry proved to be useful for limestone characterization, and data obtained can be correlated with parameters from other analyses.