Archaeometric Characterization of Submerged Sasanian Stucco From Ghaleh Guri, Western Iran

The Ghaleh Guri archaeological site, a late Sasanian site with a building complex dated to 591–628 ce , lies along an ancient road linking the western Zagros to Mesopotamia. Its architectural remains, adorned with stucco, faced annual river floods yet remained stable for centuries. This study examines the stucco decorations and plaster to identify features that contribute to their stability. Samples underwent ICP‐OES, XRD, and SEM–EDS analyses, revealing that prolonged moist conditions over a millennium resulted in a dense microstructure of coarse gypsum networks, creating a stable structure. The findings highlight the crystal changes of the gypsum over a millennium and its remarkable strength before ultimately being submerged.