Zagadnienie południowo-wschodniego przedłużenia aulakogenu środkowopolskiego w geosynklinie karpackiej
Abstract
THE PROBLEM OF SOUTH-EASTERN EXTENSION OF THE MID- POLISH AULACOGEN IN THE AREA OF THE CARPATHIAN GEOSYNCLINE
Summary
Some papers ascribing aulacogen features to very thick Permian-Mesozoic structural complex in central part of the Polish Lowlands, recently appeared in Polish geological literature. W. Pożaryski and K. Żytko also see such faetures in central Carpathian Foredeep, adjoining part of the Northern Carpathians as well as some parts of the Eastern Carpathians. The results of studies on geological structure of these areas, carried out for over 30? 40? years by the present author, make it desirable to verify the above views. First of all it should be noted that Mesozoic sections of the Carpathian Foredeep display large stratigraphic gaps and strata occurring there tend to thin or even wedge out towards the Carpathians, which speaks against the aulacogen form of this area. Moreover, Upper Miocene rocks infilling the Foredeep represent Alpine cycle in its evolution. The Carpathians were included into the aulacogen by these authors by taking into account their present setting. That is why I carried out an attempt to reconstruct conditions prevailing in the past in this part of the geosyncline. In that attempt, I looked for answers for the following questions: 1) the position of north-eastern frame of the geosyncline, 2) extent of autochtoneous Miocene beneath the Carpathians, 3) extent of basin of the folded Miocene, and 4) original position and width of sedimentary basin of the Borysław-Pokucie and Skole (Tarcau) units in palinspastic reconstruction. The analysis was carried out with the use of geological maps and deep borehole data from Poland; USSR and Romania, compiled in the form of over a dozen cross-section. The course of the buried Kielce-Dobrogean mountain belt (the hypothesis of existence of which has been put forward by R. Zuber at the beginning of the century), mainly built of Precambrian phyllites and acting as external boundary of the geosyncline in the studed section, is reconstructed. The data on great thickness of some flysch series are revised, showing that real thickness of these series does not differ from typical for the Flysch. The results of the analysis are shown in Fig. 1.
In concluding, I have to say that I do not see reasons for assuming extension of the Mid-Polish aulacogen to SE, especially into the area of the Carpathian geosyncline, characterized by its specific development.
Summary
Some papers ascribing aulacogen features to very thick Permian-Mesozoic structural complex in central part of the Polish Lowlands, recently appeared in Polish geological literature. W. Pożaryski and K. Żytko also see such faetures in central Carpathian Foredeep, adjoining part of the Northern Carpathians as well as some parts of the Eastern Carpathians. The results of studies on geological structure of these areas, carried out for over 30? 40? years by the present author, make it desirable to verify the above views. First of all it should be noted that Mesozoic sections of the Carpathian Foredeep display large stratigraphic gaps and strata occurring there tend to thin or even wedge out towards the Carpathians, which speaks against the aulacogen form of this area. Moreover, Upper Miocene rocks infilling the Foredeep represent Alpine cycle in its evolution. The Carpathians were included into the aulacogen by these authors by taking into account their present setting. That is why I carried out an attempt to reconstruct conditions prevailing in the past in this part of the geosyncline. In that attempt, I looked for answers for the following questions: 1) the position of north-eastern frame of the geosyncline, 2) extent of autochtoneous Miocene beneath the Carpathians, 3) extent of basin of the folded Miocene, and 4) original position and width of sedimentary basin of the Borysław-Pokucie and Skole (Tarcau) units in palinspastic reconstruction. The analysis was carried out with the use of geological maps and deep borehole data from Poland; USSR and Romania, compiled in the form of over a dozen cross-section. The course of the buried Kielce-Dobrogean mountain belt (the hypothesis of existence of which has been put forward by R. Zuber at the beginning of the century), mainly built of Precambrian phyllites and acting as external boundary of the geosyncline in the studed section, is reconstructed. The data on great thickness of some flysch series are revised, showing that real thickness of these series does not differ from typical for the Flysch. The results of the analysis are shown in Fig. 1.
In concluding, I have to say that I do not see reasons for assuming extension of the Mid-Polish aulacogen to SE, especially into the area of the Carpathian geosyncline, characterized by its specific development.