Capturing technological crossovers between clay crafts: An archaeometric perspective on the emergence of workshop production in Late Iron Age northern Spain

In the Iberian Iron Age, the transition to workshop-based pottery production involved the use of innovative tools (the potter’s wheel and kiln) and dedicated workspace. This facilitated an intensification of production, with repercussions for consumption practices and the economy. Cross-craft comparison can contribute to understanding the transmission processes underpinning this transition, as well as its impact on local craft traditions. This paper discusses an archaeometric methodology to compare the technological procedures underpinning different clay crafts to reveal crossovers and divergences that are meaningful for understanding cross craft interaction and the spread of technological innovations. We use thin-section ceramic petrography, X-Ray Fluorescence, Inductively Coupled Plasma–Mass Spectrometry, and X-Ray Diffraction to analyse the mineralogical and geochemical compositions and levels of standardisation in hand-made pottery, wheel-made ceramics, and ceramic building materials from the Late Iron Age oppidum of Monte Bernorio (Aguilar de Campoo, Palencia) and the kiln site of El Cerrito (Cella, Teruel). The results demonstrate that wheel-made pottery was produced according to a highly uniform clay preparation and clay selection procedure, which spanned the northern Iberian Plateau and largely existed in isolation from local pottery traditions. At Monte Bernorio, wheel-made pottery was made on-site from non-local clays, suggesting that suitable clays were brought to the site, perhaps by itinerant potters working on a seasonal basis. Technological traditions were thus largely polarised, demonstrating that knowledge, skills, and markets relating to workshop-produced pottery were enacted by a segment of society operating as part of a closed technological system.