First Direct Dating for the Construction and Modification of the Baphuon Temple Mountain in Angkor, Cambodia

Abstract

Architecture represents key evidence of dynastic practice and change in the archaeological world. Chronologies for many important buildings and sequences, including the iconic temples of medieval Angkor in Cambodia, are based solely on indirect associations from inscriptions and architectural styles. The Baphuon temple, one of the last major buildings in Angkor without textual or scientifically-derived chronological evidence, is crucial both for the context and date of its construction and the period when its western façade was modified into a unique, gigantic Reclining Buddha. Its construction was part of a major dynastic change and florescence of the Hindu-Mahayana Buddhist state and the modification is the key evidence of Theravada Buddhist power after Angkor's decline in the 15th century. Using a newly-developed approach based on AMS radiocarbon dating to directly date four iron crampons integrated into the structure we present the first direct evidence for the history of the Baphuon. Comprehensive study of ferrous elements shows that both construction and modification were critically earlier than expected. The Baphuon can now be considered as the major temple associated with the imperial reformations and territorial consolidation of Suryavarman I (1010–1050 AD) for whom no previous building to legitimize his reign could be identified. The Theravada Buddhist modification is a hundred years prior to the conventional 16th century estimation and is not associated with renewed use of Angkor. Instead it relates to the enigmatic Ayutthayan occupation of Angkor in the 1430s and 40s during a major period of climatic instability. Accurately dating iron with relatively low carbon content is a decisive step to test long-standing assumptions about architectural histories and political processes for states that incorporated iron into buildings (e.g., Ancient Greece, medieval India). Furthermore, this new approach has the potential to revise chronologies related to iron consumption practices since the origins of ferrous metallurgy three millennia ago.

Absolute dating of lead carbonates in ancient cosmetics by radiocarbon

“…During the manufacture of the iron alloy, carbon from charcoal combustion is incorporated by diffusion into the metal and forms cementite (Fe 3 C) 4 . This approach has shed new light on the technical skill and intentions of cathedral builders in Europe 5 and on the chronology of the Angkor temples in Cambodia 6 .…”

‘Guard the Good Deposit’: Technology, Provenance and Dating of Bipyramidal Iron Semi‐Products of the Durrenentzen Deposit (Haut‐Rhin, France)

“…The steely zones (which contain the carbon to be measured) are detected during the metallographic study of the object (see above). The preparation, collection and combustion of the samples collected followed a newly developed approach based on accelerator mass spectrometry (AMS), detailed in Leroy et al (,b). Finally, the CO 2 samples were reduced to graphite and measured by AMS in the LMC14 laboratory.…”

“…Thanks to recent archaeometric methods to process analyses (Fluzin et al ; Galili et al ), provenance studies (Desaulty et al ; Leroy et al ; Disser et al , ) and dating of iron metals (Leroy et al ,b), we were able to envisage further clarification of as yet unanswered questions. These methods allow different levels of specialization among craftsmen to be determined; for example, by characterizing the know‐how applied to the manufacture of intermediary products.…”

Iron Bar Trade between the Mediterranean and Gaul in the Roman Period: 14C Dating of Products from Shipwrecks Discovered off the Coast of Saintes-Maries-de-la-Mer (Bouches-du-Rhône, France)

“…Another major limitation is related to the low carbon content of the ancient iron, heterogeneously distributed within the metallic matrix. Considering these different risks of misdating, Leroy et al (2015aLeroy et al ( , 2015b developed an adapted methodology for dating iron following a detailed study of the metallic matrix.…”