Stratygrafia i tektonika utworów paleozoicznych Gór Świętokrzyskich w nawiązaniu do poglądów Jana Czarnockiego

Abstract

Przedstawiono fundamentalne znaczenie dokonań badawczych Jana Czarnockiego w regionie świętokrzyskim. Na tle Jego dorobku omówiono osiągnięcia kontynuatorów dzieła tego badacza w zakresie stratygrafii, paleontologii, paleogeografii i tektoniki. Szczególną uwagę zwrócono na budowę geologiczną jednostki łysogórskiej, i na rozwój tektoniczny głównej dyslokacji świętokrzyskiej (nasunięcie świętokrzyskie).

STRATIGRAPHY AND TECTONICS OF PALEOZOIC DEPOSITS FROM THE GÓRY ŚWIĘTOKRZYSKIE WITH REFERENCE TO JAN CZARNOCKI'S IDEAS

J. Czarnocki (1919, 1927) established principles of chrono-, litho- and biostratigraphy of the Cambrian from the western Góry Świętokrzyskie. He identified Middle Cambrian and trilobite assemblages of the Upper Cambrian zones 3–5 in the northern region, and evidenced some Lower and Middle Cambrian zones in the southern region. Subsequent researchers (as e.g. S. Orłowski, 1957, 1964; J. Samsonowicz, 1960, W. Bednarczyk 1970; H. Żakowa, L. Jagielska, 1970) described new faunal assemblages of the Subholmia, Holmia, Protolenus and Paradoxides oelandicus zones from the Kielce region. Moreover, there were described fossils typical of the 6th zone of :the Upper Cambrian (E. Tomczykowa, 1968) and remains of primitive Metazoa (Corallicyathida), and lithostratigraphic subdivision was proposed for the northern region.

J. Czarnocki (1928a, 1939) was genuinely interested in the Ordovician of the Góry Świętokrzyskie. His works were continued after World War II, with special attention being given to paleontological studies on Graptolithina, Inarticulata, Trilobita, Conodontophorida and microflora.

J. Czarnocki (1919) greatly contributed to the establishment of the subdivision of the Silurian. He noted lithological and stratigraphical bipartity of that system and gathered a rich collection of benthic and planktonic faunas. Further studies carried out primarily by E. Tomczykowa and H. Tomczyk confirmed J. Czarnocki's ideas.

J. Czarnocki (1919, 1936) was also interested in the Devonian. He revised the earlier views, introduced new lithostratigraphic names, precised boundaries of regional zones, and found differences in the development of the Lower Devonian in southern and northern parts of the Góry Świętokrzyskie. The specimens which he continuously collected gave rise to collection of Devonian fauna which is unique on the world scale (e.g. Famennian cephalopods). His studies, particularly paleozoological studies on the Devonian were continued by numerous researchers.

Among other things, J. Czarnocki discovered the Carboniferous rocks (1916). Further studies on these deposits made it possible to refine previous· stratigraphic interpretations of the Carboniferous (H. Żakowa, 1970, 1971, in press). In the case of the Permian, J. Czarnocki studied the Zechstein. Together with J. Samsonowicz (1913, 1915) he introduced tripartite subdivision of the Zechstein, and subsequently he published a summary of the Zechstein problem (1923). Boreholes made after World War II made it ,possible to divide the Zechstein into 4 cyclothems (see e.g. K. Pawłowska, 1964) as well as to find the Rotliegendes, deposits (A. Kostecka, 1966).

When discussing the tectonics of the Góry Świętokrzyskie it should be stated that J. Czarnocki and J. Samsonowicz put forward the hypothesis of miogeosynclinal nature of the Vendian and Paleozoic in that area. Since 1927 had been J. Czarnocki emphasizing flysch nature of the Cambrian deposits which is still valid  interpretation. Lithological, facial, and tectonic analyses of the Vendian and older

Paleozoic, and the analyses of relationships between the Devonian and its sub-stratum implicate (J. Czarnocki, 1919, 1936, 1951) that the miogeosynclinal megacycle ended during the Young Caledonian movements at the turn of the Silurian and Devonian, at least in southern part of the Holy Cross Mts. These movements were accompanied by diabase and lamprophyre intrusions. That megacycle consist of three cycle's forming three structural stages: Upper Precambrian (Małopolska), Vendian-Cambrian (Sandomierz) and Ordovician-Silurian (Young Caledonian) stages.

Young Caledonian fo1ds are trending WNW–ESE (azimuths 110–125°, the Świętokrzyski direction), being more strongly marked in the south – i.e. in the Kielce region – than in the north, Łysogóry region.

According to J. Czarnocki, the Old Paleozoic miogeosynclinal megacycle was developing throughout the Devonian and Carboniferous and was closed by the Variscan movements. According to J. Znosko and Z. Kowalczewski (1971), the Łysogóry region represents a part of the giant depressional zone formed in the Early Paleozoic and subsequently modified into a intermontane depression after the Young Caledonian movements. This region is tectonically bipartite and gaps and discordances are especially common in the Cambrian, Ordovician and Upper Silurian-Lower Devonian sections.

It can be assumed that the Variscan tectonics of the Góry Świętokrzyskie is of a block type. If this is the case, its evolution would be determined by tectonicactivity of Older Paleozoic substratum blocks separated: by Caledonian dislocations. regenerated and modified in the Late Paleozoic and Mesocenozoic.