Iron and Architecture in Angkor: Metal as a Carbon-Based‑ Temporal Record for Chronological Insights

Stéphanie Leroy1*, Emmanuelle Delque‑Kolic2, Enrique Vega1, Mitch Hendrickson3, TIN Tina4, CHHAY Visoth5, and Christophe Pottier6

More than a mere metal, iron has long been a strategic resource, shaping human practices and interactions with the environment. During the Angkorian period (9th–14th centuries), Cambodia was no exception: iron was employed in diverse contexts, but its role in architecture was particularly prominent. Temples, built and transformed over time, structured the organisation of Angkor, and iron objects—from tools shaping stone to clamps securing blocks—recur in monumental constructions. Some have been recovered through restoration campaigns and are now held in various collections, including the National Museum of Cambodia and those of the research teams involved. The studied corpus mainly consists of iron clamps, whose repeated use in architectural contexts allows comparative analyses. These objects serve as a medium to explore the practices, usages, and social values of Angkorian society. Archaeometallurgy examines iron from ore to finished objects and from the natural environment to contexts of use, documenting material, social, economic, and cultural dimensions. The energy invested in production is recorded through carbon: solar energy captured by trees fuels smelting, and the wood’s ¹⁴C signature provides a chronological marker measurable by AMS, embedding both time and energy in the metal. Iron thus supports the investigation of temporal and social dynamics, situating objects within architectural sequences. By combining location, type, use, production history, and construction phases, iron helps document chronological moments in temple construction. These observations and analyses offer a perspective on how clamp characteristics may relate to the building and how this relationship could have evolved over time, pointing to avenues for further study. This paper presents the current state of research, with examples from key phases of Angkorian architecture, based on several years of field investigations and laboratory work within the IRANGKOR project.