The study of biogenic silica in animal dung deposits from the Moscow Kremlin, Russia

several ancient settlements from central russia contain animal dung deposits as a part of their cultural layers. this research was focused on animal dung of different ages sampled in the archeological dig in taynitsky garden, moscow kremlin, russia. the method of research was microbiomorphic analysis. the distribution of silica microbiomorphs and the composition of phytolith complexes were analyzed as the most informative. it is possible to see that indicators of open waters (diatoms and spicules) were identified only in one sample (the earliest one dated to the beginning of the 15th century). phytolith complexes also changed: the samples from layers dated to the late 15th and the early 16th centuries include a lot of cereal straw phytoliths. this fact definitely indicates changes in the animals' diet. phytoliths from mosses and reeds show that those plants were used as animal bedding. an abundance of fragments and unformed silica particles suggests that grasses and herbs were mowed in summer, when the phytolith formation process had not yet completed. it is possible to say that at the end of the 15th century animals consumed water from wells, suggesting that the construction of the kremlin wall was finished and the area became isolated from the bank of the moscow river. also, the animals' diet changed - straw became dominant instead of hay, possibly linked to a political and economical situation in the country. conclusions are in reasonable agreement with archeological and historical data.