Linking pedological and atmospheric environments for the conservation and management of earthen archaeological sites: development of a novel technique

Abstract

Exposed in-situ earthen archaeological structures are extremely prone to accelerated deterioration. Environmental cycles that cause swelling, salt efflorescence, and biological decay are but a few ways this breakdown is exacerbated, resulting in earthen archaeological remains rapidly losing coherence, shape, and ultimately cultural value. Several invasive methods have been attempted to cessate this process, to varying effectiveness. However, only recently has quantified site deterioration been correlated with environmental data. Results from these reports showed that the soil moisture of walls and profiles could potentially be used as an indicator of earthen archaeology deterioration rates. Determining any link between the soil moisture content surrounding an archaeological site and its exposed atmosphere could be beneficial when developing site management plans to mitigate deterioration. To determine if such a link exists, four soil moisture profile probes were installed at Vésztő-Mágor, a sheltered, prehistoric earthen archaeological site located in modern-day Hungary. The shelter induces severe microclimatic fluctuations whilst removing several external factors that impact deterioration, such as wind and sun exposure, providing a scenario that is advantageous for detecting any link. The novel horizontal installation of the probes in a vertical column captured moisture data within unexcavated archaeological horizons. This data was then compared to relative humidity data acquired around excavated archaeological profiles. Through the application of a Bayesian autoregressive AR(1) logistic model, the data suggests that a link between these two environments exists. Furthermore, moisture probe data confirms that the excavation of archaeological profiles at Vésztő-Mágor impacts unexcavated archaeological horizons at least 30 cm inward. This paper discusses the implementation of this method, the statistical analysis of the data, and its implications for managing earthen archaeological sites.