„Wielkoskalowe" różnice poglądów i interpretacji
Abstract
„LARGE-SCALE" DIFFERENCES IN POINTS OF VIEW AND INTERPRETATIONS
Summary
The paper presents a critical review of a hypothesis according to which large-scale strike-slip movements took place along the Teisseyre-Tornquist tectonic zone in Poland in the Ordovician and Silurian. It is emphasized that sharp differences in facies, thickness and folding of coeval series from opposite sides of the „strike-slip fault" were not proven to be not due to tectonic shortening in the transversal section geosynclinal area-epicontinental area, on the basis of paleotectonic reconstructions. Pre-Dalslandian and pre-Baikalian rocks of the Rachów and Bukowina massifs are shown to be situated closer to the Gothian sockle of the Old Platform than Dalslandian and Baikalian rocks of Dobrogea, which contradicts the above hypothesis. Attention is drawn to the fact that lack of data on crystalline basement in central and north-western Poland cannot be treated as a support for the hypothesis. At the same time it is emphasized that magnetic image should not be interpreted tectonically, as crystalline rocks occurring west of the Teisseyre-Tornquist zone have passed the Curie point and they were repeatedly subjected to rotations and repeated changes of Earth magnetic poles. The Y-shape of the Caledonian orogen in Europe is also interpreted in a different way. This phenomenon is here treated as normal and explainable in all the orogenic belts in terms of influence of central massifs, microcontinents and old plates. Seven geological cross-sections given in the discussed paper cannot be treated as an argument confirming the hypothesis since they merely give graphic representation of the views of individual authors on the contact of fold zone and the Old Platform. The cross- sections represent artistic visions and helplessness in interpretation. There is also discussed coexistence of phenomena excluding one another, in Figs. 3 and 4, e.g. the existence of broken-up and translocated midoceanic ridge and Protoatlantic rift outside the shelf of the Prototethys and, at the same time, the youngest Caledonides which have to mark closure of the ocean. Therefore, the growth of the Protoatlantic in the Variscan epoch is negated (Appalachians!) as that had to be the time of final closure of southern sector of the Protoatlantic and not the time of its growth.
The view that close contact of differently developed coeval series speaks in favour of strike-slip movement is seriously denied; common fold-nappe approach leads to the same contacts. As examples, are given such contacts from Caledonian, Variscan and Alpine belts, especially direct contact of schistes lustres and the Brianconnais zone.
Summary
The paper presents a critical review of a hypothesis according to which large-scale strike-slip movements took place along the Teisseyre-Tornquist tectonic zone in Poland in the Ordovician and Silurian. It is emphasized that sharp differences in facies, thickness and folding of coeval series from opposite sides of the „strike-slip fault" were not proven to be not due to tectonic shortening in the transversal section geosynclinal area-epicontinental area, on the basis of paleotectonic reconstructions. Pre-Dalslandian and pre-Baikalian rocks of the Rachów and Bukowina massifs are shown to be situated closer to the Gothian sockle of the Old Platform than Dalslandian and Baikalian rocks of Dobrogea, which contradicts the above hypothesis. Attention is drawn to the fact that lack of data on crystalline basement in central and north-western Poland cannot be treated as a support for the hypothesis. At the same time it is emphasized that magnetic image should not be interpreted tectonically, as crystalline rocks occurring west of the Teisseyre-Tornquist zone have passed the Curie point and they were repeatedly subjected to rotations and repeated changes of Earth magnetic poles. The Y-shape of the Caledonian orogen in Europe is also interpreted in a different way. This phenomenon is here treated as normal and explainable in all the orogenic belts in terms of influence of central massifs, microcontinents and old plates. Seven geological cross-sections given in the discussed paper cannot be treated as an argument confirming the hypothesis since they merely give graphic representation of the views of individual authors on the contact of fold zone and the Old Platform. The cross- sections represent artistic visions and helplessness in interpretation. There is also discussed coexistence of phenomena excluding one another, in Figs. 3 and 4, e.g. the existence of broken-up and translocated midoceanic ridge and Protoatlantic rift outside the shelf of the Prototethys and, at the same time, the youngest Caledonides which have to mark closure of the ocean. Therefore, the growth of the Protoatlantic in the Variscan epoch is negated (Appalachians!) as that had to be the time of final closure of southern sector of the Protoatlantic and not the time of its growth.
The view that close contact of differently developed coeval series speaks in favour of strike-slip movement is seriously denied; common fold-nappe approach leads to the same contacts. As examples, are given such contacts from Caledonian, Variscan and Alpine belts, especially direct contact of schistes lustres and the Brianconnais zone.