Abstract | The article discusses the question of the genesis of the so-called “sand” layer, which is a characteristic feature of the cultural layer of the early Golden Horde period in the central part of Bolgar. Based on a complex of physicochemical and microbiomorphic methods, it was shown that in all cases this layer stand out sharply from the rest in terms of the content of gross phosphorus, amorphous and biogenic silica. Therefore the genesis of this layer is not mineral, but mainly biogenic in nature. Hypotheses have been put forward about the origin of this layer - as accumulations of manure of herbivores or remnants of adobe buildings. |