Detection of archaeological soils through portable VIS-NIR spectrometer

Reflectance spectroscopy is widely used to rapidly and quantitatively determine soil properties. This study introduces a method to identify archaeological soils, which are soils influenced by ancient anthropogenic activities, from the surrounding landscape using a portable VIS-NIR reflectance spectrometer. To identify spectral features of archaeological soils, the method statistically calculates the difference between an archaeological soil spectrum and a non-archaeological soil spectrum. Such difference is quantified by an R-value. Any soil spectra with R-values larger than 1 are more likely to be anthropogenically-affected soils.

Previously, the method was successfully applied to several archaeological sites in Italy and Hungary showing clear differences between the archaeological and non-archaeological soils. In this study, we will investigate the R-values for soils from prehistoric settlement sites in Sintanjin, Korea, and compare these to the results from Italy and Hungary. Both in-situ and topsoil spectral measurements were gathered using a portable ASD spectrometer. In this site, soils from kitchen areas showed R-values between 2.5 and 4.2, while soils from graves ranged from 1 to 1.4. The results indicate that the R-values vary a lot depending on the type of archaeological remains and a more detailed investigation of the method to various archaeological remains is essential to improve the method. One of our interesting results is that the method can be applied to soil spectra gathered with low-resolution spectrometers which leads to the possibility of applying continuous 2D spectral imaging applications.