Evaluating Earth Construction Techniques on Ancient Architecture: An Exploratory Use of Empirical Field Tests in West Asia (Tell Zurghul/Nigin)

The research empirically evaluates ancient earth construction techniques through the analysis of archaeological adobe samples from Tell Zurghul/Nigin, south-eastern Iraq, dating from the mid-5th to mid-3rd millennium BCE. Simple, non-standardised empirical field tests were employed to obtain preliminary material characterisations, valuable for pilot assessments and gaining further significance when compared with quantitative analytical results. Their application evaluates the functionality of these tests while integrating archaeological insights with material science, underscoring the importance of multidisciplinary collaboration in earthen heritage conservation. Sixteen samples—fifteen archaeological and one modern—were analysed to assess raw material composition, grain size, clay behaviour, organic content, cohesion in wet and dry states, and surface adhesion. Results demonstrate notable homogeneity in material composition across the time span, primarily fine sands with minimal clay or silt. This suggests favourable drainage, minimal shrinkage, and reduced cracking but limited cohesion, implying a potential need for stabilisers such as plastic clays or fibres in construction. These findings inform conservative strategies for the preservation and restoration of earthen structures at the site.