Kilka uwag o badaniach tektogenezy kaledońskiej i waryscyjskiej w Polsce

Józef Oberc

Abstract


Fałdowania kaledońskie zaznaczyły się w kilku odległych od siebie jednostkach, natomiast ruchy waryscyjskie objęły cały obszar i serie od starszego paleozoiku począwszy. Między proterozoikiem i fanerozoikiem istnieje przerwa i niezgodność niedostrzegana przez tych autorów, którzy widzą fałdowanie utworów prekambru dopiero w paleozoiku. lntruzje waryscyjskie są posttektoniczne. Wtargnęły one głównie w utwory prekambru. Należy je wiązać z ustaniem kompresji danej fazy tektonicznej, a wiek radiometryczny - z osiągnięciem temperatury, w której mogą gromadzić się produkty rozpadu radioaktywnego.

SOME REMARKS ON RESEARCH OF THE CALEDONIAN AND VARISCAN TECTOGENESIS IN POLAND

The Caleodnian folding of the Lower Palaeozoic series occurs in only several units in south-western Poland. In other units. li continuous sedimentation lasted through the Silurian/Devonian border and the Variscan folding consisted of the Lower Palaeozoic and Variscan sequence. A structural evolution of the Variscides ended in the Sudetic and Asturian phase. Molasse developed from the Upper Carboni-ferous. This step of the young platform does not contain Zechstein.

Determination of the lower border of the Caledonian/Variscan tectogenesis makes difficulties in determination of the Proterozoic/Palaeozoic border in the field and boreholes, i.e. the border of time. After the author there is no the youngest links of both Proterozoic, since its youngest link -the Kamien beds -enters the country only as a fragment. and Palaeozoic. Some scientists do not notice this fact and see continuity of rock series and of time between Proterozoic and Fanerozoic, the Precambrian folding however was located not before Palaeozoic-Devonian in particular. Then a deepwater marine sedimentation undisturbed with diastrophic formations took place. The Cambrian/the basement relation in the Kaczawskie Mts is not know. The lower and middle transgressive Cambrian in middle Bohemia and Upper Silesia and occurrence the Ordovician (the Karkonosze Mts). Devonian (the Eastern Sudety Mts) and Lower Carboniferous formations the Sowie Mts, Karkonosze Mts} prove discontinuity between Proterozoic and Palaeozoic. The Precambrian formations were intruded by the Variscan granitoides of various radiometric dating:. These intrusions are posttectonics. They are often related to tectonic phases. The author suggests to relate the occupying space by granites with ceasing the thrust of a given phase. The radiometric age is the age of an instant of achieving the temperature by the investigated part of intrusion in which radioactive decay products accumulated.


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