Early Sasanian landscape modification: New geoarchaeological evidence from the Ardashir Pond in southwest Iran (Palace of Ardashir, third century CE)

AbstractThe Sasanian period (224–651 CE) marked an era of large‐scale urban projects in southwest Asia, including Iran's semi‐arid highlands, with particular efforts to manipulate water bodies. This study presents a recent interdisciplinary investigation of a spring‐fed pond at the entrance of the Palace of Ardashir (Firuzabad plain, southwest Iran), part of a recently registered World Heritage site. Historical accounts suggest that the entire water system of the plain, including the pond, underwent a hydraulic re‐organization at the beginning of the Sasanian period, a fact that has never been investigated geoarchaeologically. A series of sediment cores were retrieved from the pond to probe its evolution and examine the extent of its landscape modification. The cores were sedimentologically described and radiocarbon‐dated with age–depth models established based on 57 AMS (accelerator mass spectrometry) 14C dates to understand the basin's depositional history. The results indicate that (i) Ardashir Pond has existed as part of a larger wetland complex since at least 4500 years ago, (ii) it was substantially enlarged at the beginning of the Sasanian era, and (iii) it was abandoned at the end of the Sasanian period. The Ardashir Pond is one of the first geoarchaeologically investigated case studies to demonstrate the Sasanian landscape in the framework of the “Iranshahr” sociopolitical concept.