The problem of transgressive and regressive phenomena in the accumulation of sediments entered a new phase. This was due to the study of coal-bearing formations with regard to the cyclic nature of their structure. In lithologic works on the Kuznetsk, Karaganda and other basins, and especially on the Donetsk basin, the importance of sedimentary cycles consisting of regressive and transgressive parts became clear. It was further established that regression does not repeat in reverse order the rocks and facies of the transgressive part of the cycle. It is characterized by a number of facies with special features, if even they develop at the same depths and the same distances from the shore as the transgressive facies. The respective rock features also bear the features of differences that are more and more revealed.