Phytolith studies of ash heaps of Bronze Age settlements of the southern Trans-Urals

Scientific research methods have a wide range of applications in archaeology, and in combination with the results of excavations, they provide crucial data for resolution of controversial issues. One of the debatable issues of studying the Eurasia Bronze Age is the origin of the so-called ash heaps near settlements. The presented study is devoted to the analysis of the microbiomorphic and phytolytic composition of ash layers of three settlements in the Southern Trans-Urals (transition zone from steppe to forest-steppe, Chelyabinsk Region): Stepnoye, Streletskoye-1, and Chernorechye-2. The derived analytical data suggest both similar and distinguishing features in the origin of ash heaps. The Stepnoye settlement belongs to the type of fortified settlements of the Sintashta archaeological culture; Streletskoye-1 and Chernorechye-2 are unfortified settlements that functioned mainly in the Alakul period of the Late Bronze Age. The ashy layers of all three sites were formed due to the deposition ofplant biomass. The ash heap at the Stepnoye settlement is characterized by the most representative phytolith complexes. The heap largely accumulates industrial waste, and the deposited plant biomass might have been hay. Archaeological material reveals traces related to metallurgy and bone-cutting craft. The ash heaps of Streletskoye-1 and Chernorechye-2 contained mainly household plant debris (mats, food residues, housing structures), although production waste has also been recorded. The excavations have shown that some artifacts are related to bone-cutting, butchering of animal carcasses, and the selection of material (bone, skin). Manure and hay were possibly deposited at the early stages of usage of Streletskoye-1 and Chernorechye-2 ash heaps. Phytoliths of cultivated cereals have been found in the Streletskoye-1 ash heap, which suggests import or the initial stage of agricultural development.