On certain regularities of crustal structure associated with the major geologic features of Southeastern Europe

The analysis of numerous seismic studies from various geological provinces has demonstrated that variations in crustal thickness depend primarily on the thickness of the “basaltic” layer. In some areas two M discontinuities can be found — the present one and an ancient one. The lower crust, formed in Proterozoic time is apparently still preserved. Roots exist under the former Proterozoic orogens, in spite of the complete denudation of the orogenic mountains. Younger (Paleozoic-Mesozoic) subsurface structures are not so clearly pronounced in the crustal structure. More active reconstruction of the crust seems to have taken place in the course of Alpine orogenesis.