At the beginning of the Early Iron Age, a geometric style, similar in a set of motifs and stylistic features, has spread in Eastern Europe. Its rapid development was nonlinear. The motifs of the Chornolis geometric ornaments has a lot of features characteristic of the Late Bronze Age. Traditional patterns are becoming more diverse primarily due to the expansion of the set of techniques. Multi-row compositions expand the ornamental band and significantly increase the decorated part of the vessel surface. However, a number of features of the Chornolis ornaments determine their more typical appearance for the Early Iron Age. This is the frequent use of “closed” patterns or the complication of the geometric figures themselves. However, the most innovative is the emergence of asymmetric compositions, the special appearance of which is determined by the use of complex types of symmetry. Having lost some regularity, the patterns become more varied and individual. Owing to such transformations in Zhabotyn time, a new system of geometric ornamentation appeared. It permeates into the steppe zone, this process marks the spread of “chess” motifs, which are on the dishes from the steppe burials and from the Crimea. It was during the Zhabotyn period that the horizon of geometric ceramics became most widespread in Eastern Europe. In the Northern Black Sea region its existence ends earlier than in the forest-steppe region. The development of forest-steppe culture during the final Bronze Age and the beginning of the Early Iron Age can be considered within the first model of Hallstatization, where the formation of the complex is the result of the interaction of local and foreign components. Intensity of Hallstattization increases starting from the Chornolis horizon, the innovations permeated deeper into the local environment, transforming it radically. An example of this can be the changes in the sphere of the sacred, certain manifestations of which occur already in the Chornolis time. Thus, Bilohrudivka miniature vessels are almost completely replaced by pixids. Such a replacement may involve the spread of new beliefs and rituals. The peak moment of Hallstattization is the appearance of such a phenomenon as Zhabotyn. It is characterized by the change in the nature of the process itself, in particular, the migration of cult practices. For the Zhabotyn period, such manifestations are the spread of wide ladles with complex radial ornaments, rare types of vessels and altars of the Zhabotyn type. Thus, the “ornamental explosion” is the peak of the process of Hallstattization and in particular the development of geometric ornamentation in forest-steppe culture. Powerful infiltration of the Carpathian and Danube traditions provoked the emergence of a common geometric style. The formation of this style can be considered as the expansion of sacred space, as well as the emergence of a common context of ideological and religious practices.