Patterns of Mobility in Iranian Central Plateau at the Transition From the Bronze Age to the Iron Age: Research on Strontium Isotope Ratios in Human Remains From Estark-Joshaqan

Abstract

Objectives

There is a paradigm in Iranian archeology that a mass migration of nomads from the steppe north of the Caspian Sea to the Central Iranian Plateau occurred around the beginning of the Iron Age, leading to the domination of a mobile pastoral economy in the region. Such a hypothesis was tested through strontium isotope analysis of recently excavated human remains from the cemetery of Estark-Joshaqan, dated from the Late Bronze to Early Iron Age (c. 1800–800 BCE).

Materials and Methods

We measured the ⁸⁷Sr/⁸⁶Sr ratio in human dental enamel of 23 individuals from Estark and six individuals from nearby sites: Tepe Sialk (Parthian period) and Bidgol (Early Islamic period), all located near Kashan, Iran, and compared them to the local strontium isoscape based on 39 modern plant samples collected in the region.

Results

Available evidence does not support the hypothesis of permanent long-distance migration from a region with a different strontium isotope signature. Mobility was similarly low in the Late Bronze Age and the Early Iron Age, although the local resource exploitation pattern may have shifted slightly between these periods.

Discussion

There is no clear indication of nomadism, and most likely, people from Estark were agropastoralists, using a relatively limited area for grazing their livestock. Our results open a new perspective in the research of the ‘dark age’ in the Central Iranian Plateau preceding the formation of the Median state.