Chronological sequence of the Early Bronze Age graves in the Pamukli Bair Barrow at Malomirovo and the Pit-Grave Culture expansion in the Middle Tundzha Valley

The archaeological excavations of a joint Polish-Bulgarian team in 2021 at the the Pamukli Bair Barrow, near the village of Malomirovo in the Middle Tundzha River Valley, Upper Thrace, revealed ten Early Bronze Age graves, three Middle Bronze Age graves, and a Late Antique grave. Three constructive and five chronological phases were distinguished in the Bronze Age life of the barrow. The sequence of the Bronze Age features was additionally sustained by 19 radiocarbon dates, for which a Bayesian model was created. The first constructive and chronological phase dated back to 3104–2922 cal. BC (with an even earlier possible dating for one of the features, 3321–3016 cal. BC) and is related to three inhumation burials in a semi-supine position, with the head to the east, as well as scattered bones of a male individual. Three small barrow fills were piled above the three graves. The second constructive and chronological phase dated back to 2911–2892 cal. BC and is related to two graves that present all the characteristics of the Early Pit-Grave Culture. Feature 17 yielded three stone anthropomorphic stelae as well. The second barrow fill was constructed above these two graves. The third constructive and chronological phase dated back to 2881–2808 cal. BC and is related to two more features that could mark the end of the Early Pit-Grave period. Above them, the last barrow fill was piled and thus, the barrow reached its modern dimensions. Two Late Pit-Grave Culture graves were dug in the central part of that fill. They mark the fourth chronological Bronze Age phase dating back to 2681–2506 cal. BC. The fifth phase dated back to 1736–1623 cal. BC and is related to three contracted burials dug in the southern sector of the barrow. The Malomirovo sequence is the largest set of radiocarbon dates from a Bronze Age barrow in Upper Thrace. The combination of stratigraphic evidence and radiocarbon dates makes it a good starting point for further chronological and morphological studies of the Early and Middle Bronze Age mortuary practices in the region.