After a short historical review of conceptions about the "Pannonian Median Massif" or "Tisia", the distribution of Middle-Upper Carboniferous and Lower Triassic-Liassic facies is briefly examined on the two sides of the Zagreb-Zemplin line dividing into two main segments the basement of the Carpathian basin. It shows on the one hand, that the Igal-Bükk zone ("Igal-Bükk eugeosyncline" of Wein, 1969), thought to establish a connection between the NW-Dinarides and the Dinaric-type Bükkium, is only a tectonic zone and could never have been a paleogeographical unit. On the other hand, the northern, marginal part of "Tisia" ("Mecsek-Bihor crystalline belt" and its sedimentary cover;Dank &Bodzay, 1971) exhibits a development and facies characteristic of the northern (northeastern) marginal complex of the Tethys. Also, facies-transitions from the foreland toward the open sea are always of N → S direction. All autochthonous explanations must face the striking differences along the Zagreb-Zemplin line, which seem to exclude the possibility that the northern part of "Tisia" was a central, partly emerged crystalline ridge (no facies-transitions toward N!); it was rather part of the northern (northeastern) marginal complex of Tethys. Therefore allochthonous models suggesting largerscale horizontal movements give a much more plausible explanation. The style of Late Hercynian development and the distribution of Lower Triassic-Liassic facies zones suggest, that "Tisia" was part of the northern (northeastern) shelf of the Tethys until the end of the Liassic (in accordance with the opinion of Bleahu), then split off and was wedged in by horizontal movements between the NW-Dinarides and the Dinaric-type Bükkium by the end of the Jurassic - beginning of the Cretaceous.
ASJC Scopus subject areas
- Earth and Planetary Sciences(all)