ИСТИНА

One of the information resources on the nature and anthropogenic impacts on the city territories in the past are coals of different origin, confining in the soil, – a pyrogenic archive. Types, dimensions and rates of carbonated pieces discovered enable to establish natural fires’ regularity and character. Concerning the human modified soils, they reveal anthropogenic impact on soil and landscape during the city life. One more aspect established is the set of local wood species. Carbonaceous inclusions gained during the archaeological excavations in the historical center of the medieval city of Yaroslavl, located in the center of the East European Plain, were studied as well (city layers of 1220-1238, early 13th century, mid 12th century and arable horizons of 8-10th centuries, Early Iron Age). As background markers we used samples from underlay natural soil horizons. That made possible to reveal the coal volume input into natural soils during due to economic activities. Soil samples of the Early Iron Age coming from arable horizons confine less coal than those from house infill. Anyway, differences between the samples just mentioned are little comparing to the consecutive arable horizons. The burnt bone presence in the early 13th century pyrogenic fraction is typical for cultural layers as well. The set of wood species established nearly corresponding with the middle taiga zone Yaroslavl to be located in. The oak coal pieces from those cultural layers appear to be remains of imported wood. The Early Iron Age arable horizons confine less coal impurities as compared to those Medieval. Probably, that is due both to the less usage of wood coal in fertilizing and pieces’ poor preservation because of natural destruction. The culture layers traditionally confine more pyrogenic material as compared to the arable horizons, the part of larger pieces being higher (probably, the result of plowing).