Research on the sociocultural complexity of the Eurasian steppe in the Bronze Age has been challenged by recent advances in the prehistorical calendar chronology derived from high-precision AMS carbon-14 measurements. The medley of archaeological cultures in the Southern Urals on the border between Russia and Kazakhstan is distinguished in space with the prominent typology of ancient ceramic and burial traditions. The new chronological framework of the Bronze Age archaeology has struggled with bewildering evidence of chronologically-overlapped and contemporaneous cultures that were previously viewed as a sequential series of ancient migrations. DNA studies and the new ¹⁴C chronology changes the previous narrative about technology, interaction and migrations of ancient Indo-Iranian population.
We resampled the crumbling ruins of Bolshoi Sintashta Kurgan (BSK) at the Sintashta principal outpost of the Middle Bronze Age in the northern Eurasian Steppe and developed 18 new AMS dates from wood and burned soil. Sintashta is a prominent metallurgical, military, and early urban center dated to the interval 2100–1800 BCE. BSK is described as a large fire-worship structure built in the shape of a terraced compound resembling Mesopotamian ziggurats.
A Bayesian approach to calibration and re-analysis of the new and historical ¹⁴C data from BSK showed that the ziggurat-like double-leveled structure was built between 1500 BCE and 1300 BCE over the dilapidated Sintashta temple retaining the tholos burial. Having two structures separated in time and different size sanctuaries was very unexpected. Both temples utilized fire altars. The original Sintashta worship structure was much smaller and erected 400–500 years earlier. The second larger structure belonged to the Andronovo cultural community not the Sintashta. The new dates of BSK indicate the unity of the Sintashta and Andronovo (probably Fedorovo and Alakul) cultures that subsisted in the northern Eurasian Steppe 4000 and 3500 years ago.