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Nowe dane o litologii i biostratygrafii akritarchowej skał kambryjskich na Łysicy, najwyższym szczycie Gór Świętokrzyskich

Szczepanik Z., Malec J.

Przegląd Geologiczny

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2017

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Vol. 65, nr 9

564--575

EN

The southern slope of Łysica Mountain, which is the highest elevation of the Holy Cross Mountains, is comprised of three lithological complexes divided by parallel fault zones. The uppermost part of the succession consists of quartzitic sandstone of the Wiśniówka Formation. The formation is underlain by a complex of sandstone with mudstone interbeds, with black claystone underneath, which is exposed in the upper part of the Glęboczka ravine succession. The strata of the first and the third complexes dip northward, whereas those of the second complex dip southward. In the fault-bound zone between the second and the third complexes, there are concentrations of weathering iron ore. The black claystone, which is lithologically similar to this of the Pepper Mountains Formation, contains a taxonomically rich assemblage of organic-walled microfossils (acritarchs) diagnostic of the Upper Cambrian (Lower Furongian) successions. The new record of microfossils allows determining the age of the succession composing the Łysogóry Mountains for the first time in the history of regional geological investigation.

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Cambrian phytoplankton of the Brunovistulicum : taxonomy and biostratigraphy

Jachowicz-Zdanowska M.

Polish Geological Institute Special Papers

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2013

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Vol. 28

1--150

EN

The paper presents the results of detailed palynological studies carried out on the Cambrian deposits of the Brunovistulicum, a characteristic regional unit distinguished in sub-Devonian geology in southern Poland and NE Czech Republic. The material studied consists of drillcore samples collected from 22 boreholes that have penetrated Cambrian in southern and north-eastern parts of the Upper Silesian Block (USB) and 3 boreholes located in the Moravia region (Czech Republic). Within those boreholes, complexes of lithologically differentiated clastic rocks have been encountered below Jurassic, and Lower or Middle Devonian deposits. The age of these sediments, apart from the Goczałkowice IG 1 profile, was determined only on the basis of palynological studies. Majority of the investigated rock samples yielded very rich usually well preserved microfloristic material that allowed to make taxonomic revisions of analysed acritarch associations. Five new genera, nineteen new species and eleven species new combinations are proposed. The new and revised taxa include mainly those that appear in the Cambrian Series 2 and forms characteristic for the Cambrian Series 3. These are the following important new genera as: Ichnosphaera, Lechistania, Eklundia, Parmasphaeridium and Turrisphaeridium. The taxonomic revision and systematic analysis of acritarch associations described from the Cambrian of Brunovistulicum allowed to establish the succession of microfloral assemblages. As a result of the present studies nine distinct regional assemblage acritarch zones have been recognised – BAMA I to BAMA IX, correlated with the Cambrian series: Terreneuvian, Series 2, and Series 3. The BAMA I – Pulvinosphaeridium antiquum–Pseudotasmanites and the BAMA II Asteridium tornatum–Comasphaeridium velvetum zones are distinguished in the oldest Cambrian deposits of the Brunovistulicum and are correlated with the Platysolenites Zone. Acritarch assemblages characteristic for the older one were documented in the Borzeta Formation in the eastern margin of the Upper Silesian Block. The acritarch association of the BAMA II constrains the biostratigraphic position of the Mogilany Member of Goczałkowice Formation in the USB area. The BAMA III–VI acritarch assemblage zones: Ichnosphaera flexuosa–Comasphaeridium molliculum, Skiagia–Eklundia campanula, Skiagia–Eklundia varia and Volkovia dentifera–Liepaina plana are recognised in the Goczałkowice Formation of both the Upper Silesian and Brno blocks and comprise deposits of Schmidtiellus, Holmia and Protolenus trilobite zones in the studied area. The BAMA VII to BAMA IX zones are correlated with Series 3 of the Cambrian System and were established in the Sosnowiec Formation known only from the Sosnowiec IG 1 borehole in the Upper Silesian Block area. The BAMA VII Ammonidium bellulum–Ammonidium notatum Zone is here correlated with trilobite Acadoparadoxides oelandicus Zone, while BAMA VIII Turrisphaeridium semireticulatum and BAMA IX Adara alea–Multiplicisphaeridium llynense zones are regarded as equivalents of the Paradoxides paradoxissimus Zone. The present study indicates that the oldest Cambrian (Terreneuvian) sediments containing BAMAI Zone assemblages were deposited only in the eastern part of the Upper Silesian Block. Younger sediments, from the Terreneuvian and Series 2 with BAMA II–VI Zones assemblages were developing over much larger areas of the Upper Silesian and Brno blocks. Sediments of the Series 3 with BAMA VII–IX assemblages are known only from the northern part of the USB. The Furongian sediments, not yet found in the study area, potentially may occur in the northern part of the Block, where the Ordovician strata were found. Nevertheless, a reliable reconstruction of the Early Palaeozoic deposition within the Brunovistulicum still remains an open question, which can be solved only by new borehole data.

PL

W pracy przedstawiono wyniki szczegółowych badań palinologicznych wykonanych dla utworów kambryjskich rozpoznanych na obszarze Brunovistulicum, regionalnej jednostki tektonicznej położonej na południu Polski i w północno-wschodnich Czechach. Materiał do badań stanowiły próbki skał z 22 otworów wiertniczych zlokalizowanych w obszarze bloku górnośląskiego oraz z 3 wierceń wykonanych na Morawach (blok Brna). W wierceniach tych pod utworami jury, dewonu dolnego lub środkowego nawiercono zróżnicowane litologicznie kompleksy skał klastycznych, które poza jednym profilem - Goczałkowce IG 1 - pozbawione są przewodnich mikroskamieniałości, a ich kambryjski wiek został ustalony na podstawie badań palinologicznych. Uzyskany w trakcie badań bogaty i w większości dobrze zachowany materiał mikroflorystyczny umożliwił przeprowadzenie rewizji wielu taksonów akritarch, w tym wykreowania 5 nowych rodzajów oraz wyróżnienia 19 nowych gatunków i 11 nowych kombinacji gatunkowych. Nowe i rewidowane taksony to głównie gatunki występujące w utworach oddziału 2 i formy charakterystyczne dla oddziału 3 systemu kambryjskiego. Do najważniejszych należą następujące nowe przewodnie rodzaje: Ichnosphaera, Lechistania, Eklundia, Parmasphaeridium i Turrisphaeridium. Przeprowadzone analizy taksonomiczne zespołów akritarch udokumentowanych w utworach kambru Brunovistulicum pozwoliły na wyznaczenie w tym obszarze 9 regionalnych poziomów mikroflorystycznych - BAMA I do BAMA IX, które datują trzy kolejne oddziały kambru: terenew, oddział 2i3. Poziomy BAMA I Pulvinosphaeridium antiquum-Pseudotasmanites i BAMA II Asteridium tornatum-Comasphaeridium velvetum rozpoznano w najstarszych utworach kambru Brunovistulicum, gdzie zostały skorelowane z poziomem Platysolenites. Zespoły akritarch charakterystyczne dla poziomu BAMA I stwierdzono w utworach formacji z Borzęty udokumentowanych we wschodniej brzeżnej części bloku górnośląskiego. Kolejna asocjacja BAMA II datuje wiek kompleksu skalnego wyróżnionego w obszarze bloku górnośląskiego jako ogniwo piaskowców skolitusowych z Mogilan formacji z Goczałkowic. Zespoły akritarch charakterystyczne dla poziomów BAMA III-VI: Ichnosphaeraflexuosa-Comasphaeridium molliculum, Skiagia-Eklundia campanula, Skiagia-Eklundia varia i Volkovia dentifera-Liepaina plana, które korelowane są z poziomami Schmidtiellus, Holmia i Protolenus udokumentowano w osadach formacji z Goczałkowic, rozpoznanych w obszarach bloku górnośląskiego i bloku Brna. Utwory odddziału 3 kambru w analizowanym obszarze dokumentują trzy poziomy akritarchowe BAMA VII-IX, stwierdzone w osadach formacji z Sosnowca, udostępnionych otworem wiertniczym Sosnowiec IG 1 na bloku górnośląskim. Poziom BAMA VII Ammonidium bellulum-Ammonidium notatum należy wiązać z poziomem Acadoparadoxides oelandicus, natomiast dwa pozostałe poziomy BAMA VIII Turrisphaeridium semireticulatum i BAMA IX Adara alea-Multiplicisphaeridium llynense z poziomem Paradoxidesparadoxissimus. Z przeprowadzonych badań wynika, że najstarsze osady kambryjskie - terenewu - zawierające zespoły BAMA I tworzyły się tylko w części wschodniej bloku górnośląskiego. Osady młodsze, terenewu i oddziału 2 z zespołami BAMA II-VI rozwijały się na znacznie większym obszarze bloku górnośląskiego i bloku Brna. Osady oddziału 3 z zespołami BAMA VII-IX tworzyły się w północnej części bloku górnośląskiego. Obecność osadów furongu w analizowanym obszarze jest wielce prawdopodobna, mogą one występować w północnej części bloku, tym bardziej, że zostały tam już udokumentowane utwory ordowiku. Wiarygodne i prawidłowe odtworzenie rozwoju sedymentacji osadów dolnopaleozoicznych na obszarze Brunovistulicum pozostaje zagadnieniem otwartym, które można rozwiązać jedynie za pomocą nowych otworów wiertniczych pozwalających na poznanie pełniejszych profili tych utworów.

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Organic microfossil assemblages from the late Ediacaran rocks of the Małopolska Block, southeastern Poland

Jachowicz-Zdanowska M.

Geological Quarterly

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2011

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Vol. 55, No. 2

85-94

EN

The results of palynological investigations of the oldest siliciclastic strata recognized in the Małopolska Block, situated in southeastern Poland, within the Trans-European Suture Zone (TESZ), are summarized in this paper. Siliciclastic flysch-type rocks without macrofossils have been encountered in over 1000 boreholes within the Małopolska Block, below Paleozoic, Mesozoic, and Cenozoic deposits of various ages (from Ordovician up Miocene). The lithostratigraphy of the pre-Ordovician basement in the Małopolska Block is not fully known. Thin tuffs or tuffites layers have been found in many sections of these rocks. In some of the boreholes (e.g., Książ Wielki IG 1), a late Ediacaran age has been determined for a tuffite interlayer of the rocks underlying Ordovician strata, by U-Pb dating of zircons recovered from that tuffite, that indicated 549 š3 Ma. This article describes the palynology of samples from twelve selected profiles which contained recognizable organic microfossils, in various states of preservation. The associations recovered are dominated by small spherical forms, without any ornamentation, belonging to the Leiosphaeridia, and by fossil cyanobacteria represented by straight or coiled thread-like fragmentary specimens. Similar organic microfossil associations, with poorly differentiated species and genera, are known from many late Ediacaran occurrences.

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Cambrian organic microfossils at the border area of the East- and West-European platforms (SE Poland and western Ukraine)

Jachowicz-Zdanowska M.

Annales Societatis Geologorum Poloniae

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2011

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Vol. 81, No 3

241-267

EN

This paper contains palynological and stratigraphical characteristics of the selected Cambrian sections encountered in the basement of the north-eastern part of the Carpathian Foredeep and the Outer Carpathian margin in south-eastern Poland and western Ukraine, as well as verification of the stratigraphical position of rocks recognised so far in several sections in western Ukraine. The acritarch assemblages of the Cambrian System Series 2 are dominated by species of the characteristic early Cambrian genus Skiagia. The Cambrian Series 3 beds are documented by the assemblages with numerous specimens of the Adara alea, Cristallinium cambriense, Heliosphaeridium notatum, Eliasum llaniscum, Multiplicisphaeridium martae, and Comasphaeridium longispinosum. Furongian sediments are evidenced by strongly taxonomically diversified assemblages with large quantities of acritarchs, containing genera Timofeevia, Vulcanisphaera, Ninadiacrodium, Pirea, Leiofusa, Lusatia, or Polygonium, as well as taxa characterized by diacrodial symmetry. These assemblages are dominated by such genera, as: Dasydiacrodium or Acanthodiacrodium, and also by specimens with large polar opening of the central body, belonging to acritarchs of the “galeate” group. Within the studied Cambrian sediments, nine acritarch assemblages of differing composition were distinguished. These assemblages were correlated with faunistic zones. Ages younger than Palaeozoic, identified in some of the analysed Ukrainian sections, were determined basing on very well preserved assemblages of spores and pollen.

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New data on the stratigraphy of the Ordovician at Pobroszyn, Holy Cross Mts., Central Poland

Bednarczyk W., Stempień-Sałek M.

Acta Geologica Polonica

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2011

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Vol. 61, no. 1

47-58

EN

New biostratigraphic and lithostratigraphic data are presented for the tectonically reduced Ordovician succession at Pobroszyn in the Łysogóry region of the Holy Cross Mountains, central Poland. Only some of the chronostratigraphic units known from the Łysogóry region can be recognized in this section. However, based on lingulate brachiopods, conodonts, acritarchs and chitinozoa, the units present may be referred to the Late Tremadoc, Late Arenig, Early Lanvirn, Late Lanvirn, Early Caradoc and to the Middle Caradoc and Ashgill. New lithostratigraphic units are established in the lower part of the Ordovician of the Pobroszyn section: the Opatówka Mudstone/Sandstone Formation (?Late Tremadoc) and the Pobroszyn Sandstone Formation (Late Arenig). Three species of lingulate brachiopods are described, of which two are new: Myotreta anitae and Eoconulus lilianae. The conodonts and acritarchs are illustrated and briefly discussed.

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Litologia i zespół akritarchowy formacji z Zalesia w Górach Świętokrzyskich na tle zmian poziomu morza i paleogeografii późnego ordowiku

Trela W., Szczepanik Z.

Przegląd Geologiczny

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2009

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Vol. 57, nr 2

147-157

EN

The uppermost Ordovician in the Holy Cross Mountains is represented by sandy mudstones, sandstones and marls of the Zalesie Formation deposited during the Hirnantian regression. Two arcitarch assemblages were recognized in the studied Upper Ordovician succession of the southern Holy Cross Mountains. The first one is dominated by species of Baltisphaeridium, Polygonium, Exculibranchium, Orthosphaeridium, Ordovicidium, Peteinosphaeridium, Multiplicisphaeridium, which occur in the upper Caradoc deposits. Upward in the section, these taxa are replaced mainly by diversified species of Veryhachium occurring together with Domasia, Deunfia, Leiofusa, Polygonium, Cheleutochroa, Multiplicisphaeridium and Polygonium. In the Zalesie Formation (upper Ashgill) they are accompanied by the redeposited Furongian/Lower Ordovician specimens and the Middle Ordovician species of the peri-Gondwanian affinity (e.g. Frankea), which were likely transported from Avalonia during collision of this terrane with Baltica.

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Ordowickie akritarchy bloku górnośląskiego

Jachowicz M.

Przegląd Geologiczny

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2005

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Vol. 53, nr 9

756-762

EN

Lower Palaeozoic sediments of the Upper Silesia Block have not been equally well investigated. Lower Cambrian sediments found in the southern and eastern marginal parts are so far best recognized. Sediments younger than Lower Cambrian (Middle Cambrian and Ordovician) are documented only in some boreholes. This paper presents new data about the distribution of Ordovician acritarch assemblages in this area. Ordovician microfossils were documented in three boreholes: 45–WB, 43–WB and 24–WB. In case of the latter, they represent the first stratigraphic record. The oldest assemblages of Llanvirn age were recorded in the borehole 43–WB. The Llanvirn and Caradoc sediments may also occur in the borehole 24–WB. Acritarchs known mainly from Middle Ordovician–Caradoc occur in the profile 45–WB. The microfossil assemblages recorded in Ordovician sediments of the Upper Silesia Block show mixed character, with genera and species typical for both Baltic and Mediterranean provinces.

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Ordovician–Silurian boundary in the Bardo Syncline, Holy Cross Mountains, Poland—new data on fossil assemblages and sedimentary succession

Masiak M., Podhalańska T., Stempień-Sałek M.

Geological Quarterly

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2003

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Vol. 47, No 4

311-–330

EN

A gradual transition from sandy through silty to clayey strata occurs near the Ordovician–Silurian (O/S) boundary in the southern part of Holy Cross Mountains, in the Bardo Syncline. Three graptolite biozones are distinguished for the O/S boundary interval deposits: ?persculptus, ascensus-acuminatus and vesiculosus. The first, rare graptolites appear below “graptolitic shales” in the ?persculptus Biozone. The diversity of the assemblage increases in the next two biozones. An analysis of acritarch frequency shows a decrease of acritarch frequency at the O/S boundary and then a gradual increase in the lower part of the ascensus-acuminatus biozone with a maximum in the vesiculosus Biozone. The taxonomic diversity of the acritarch assemblage shows a similar trend although the maximum of acritarch frequency observed in the vesiculosus Biozone do not coincide the maximum of acritarch taxonomic diversity.

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The Ordovician rocks of Pobroszyn in the Łysogóry region of the Holy Cross Mountains, Poland

Trela W., Salwa S., Szczepanik Z.

Geological Quarterly

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2001

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Vol. 45, No 2

143-154

EN

In the village of Pobroszyn near Opatów, a faulted section of Ordovician deposits represented by upper Tremadoc clayey-silty lithofacies, upper Arenig carbonate-phosphorite lithofacies and Upper Ordovician claystones with limestone interbeds, were identified. The upper Tremadoc is dated on basis of acritarch. This is the first time that upper Tremadoc deposits have been documented in the Łysogóry region. The late Arenig transgressive deposits were probably preceded by emergence in the latest Tremadoc and early Arenig. The Ordovician rocks from Pobroszyn are intensely tectonised. Two groups of faults, oblique and longitudinal, are distinguished. The first one strikes from 120-140°, and dip to NE at 40-45°, and the second one that strikes 15-25° and dips 65-80° to E.

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Acritarchs from Cambrian deposits of the southern part of the Łysogóry unit in the Holy Cross Mountains, Poland

Szczepanik Z.

Geological Quarterly

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2001

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Vol. 45, No 2

117-130

EN

The palynology of the Cambrian claystones and mudstones of the Góry Pieprzowe Shale Formation in the southern part of the Łysogóry region (Holy Cross Mts., Poland) are described. These deposits had been referred to the Middle Cambrian of the Paradoxides paradoxissimus and Paradoxides forchhammeri Superzones. Here, rocks from 10 shallow drillings and several exposures in the Opatów region have been examined. Scarce and poorly preserved acritarch assemblages contain several forms that are indicative for the Upper Cambrian, while the genera Acanthodiacrodium, Cymatiogalea, Stelliferidium, Trunculumarium, Nellia, Impluviculus, Calyxiella, and Veryhachium excludes the possibility of a Middle Cambrian age. Rather, these forms suggest the Upper Cambrian, most probably its middle and upper part. The occurrence of the rocks of this age to both north and south of the Łysogóry quartzite outcrops indicates tectonic repetition of the geological structure in the Main Range of the Holy Cross Mountains.The dark colours of palynoflora from the Pieprzowe Mountains in Sandomierz are identical with the colours of the Cambrian microflora from the Łysogóry region, and differ from the bright colours characterising organic matter in the Kielce region of the Holy Cross Mountains. This suggests a tectonic relation of the Pieprzowe Mountains with the Łysogóry region rather than with the Kielce region, as hitherto thought.

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Chitinozoans and acritarchs from the Ordovician of the Skibno 1 borehole, Pomerania, Poland : implications for stratigraphy and palaeography

Wrona R., Bednarczyk W., Stempień-Sałek M.

Acta Geologica Polonica

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2001

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Vol. 51, nr 4

317-331

EN

Biostratographical results of this palynological study agree with those of previous research on graptolites from the Ordovician of the Skibno 1 borehole in the Koszalin - Chojnice Structural Zone, Polish portion of the Pomerania Terrane. They indicate that the investigated core interval can be attributed to the uppermost Llanvirn (Landeilo) - lower Caradoc, and correspond to the teretiusculus and gracilis through the multidens graptolite biozones. Recovered chitinozoan species, including Belonechitina robusta, Conochitina chydaea, C. dolosa, Lagenochitina aff. capax, Spinachitina bulmani, and the index species Laufeldochitina stentor are restricted to the upper Llanvirn - lower Caradoc, the latter species delimits the stentor chitinozoan biozone (upper Uhaku and Kukruse stages). The following identified acritarchs are regarded as biosratigraphically significant: Goniosphaeridium splendens, Ordovicidum elegantulum, O. heteromorphicum, O. nanofurcatum, O. nudum, and are characteristic for the Caradoc. The presence of conodont Scabbardella altipes and ichnofossil Alcyonidiopsis pharmaceus, both characteristic of high palaeolatitudes, as well as lithological similarities between the investigated strata and their equivalents from Rugen indicate that Pomerania could have been situated at relatively high latitudes during the upper Llanvirn to lower Caradoc. These observations together with palynological results support a hypothesis that Pomerania was a terrane derived from Avalonia and accreted to the margin of the East European Craton.

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Utwory prekambryjskie w rejonie Bochnia-Tarnów-Dębica

Moryc W, Jachowicz M.

Przegląd Geologiczny

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2000

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Vol. 48, nr 7

601-606

PL

Badania geologiczne i mikroflorystyczne dotyczą utworów prekambryjskich, występujących w rejonie Tarnowa (południowa Polska). W utworach iłowcowych i mulowcowych (metaargillity, metaaleurolity) występujących w otworach wiertniczych Zalasowa I i Stawiska 1, stwierdzono zespoły mikrojlory (Acritarcha), wskazujące na prekambryjski wiek tych osadów. Przeprowadzone badania strukturalne prekambryjskiej powierzchni erozyjnej wskazują na znaczne jej zdyslokowanie i zróżnicowanie pod względem głębokości jej występowania. W południowej strefie opracowanego obszaru, pomiędzy odwiertami Brzozowa 1 i Zakliczyn I a otworem Siekierczyna IG 1, zarysowuje się strefa dyslokacyjna. Interpretowana jest ona jako SE przedłużenie strefy dyslokacyjnej Lubliniec-Kraków-Rajbrot, rozdzielającej dwa główne elementy tektoniczne przedgórza Karpat, megablok górnośląski i megablok małopolski. Zrzut podłoża skonsolidowanego bloku Rajbrot-Siekierczyna, zaliczanego już do megabloku górnośląskiego, oceniany jest na około 2-3 km względem podłoża rejonu Zakłiczyn - Brzozowa, należącego już do megabloku małopolskiego

EN

The geological and microfloristic investigations concern Precambrian rocks which occur in Tarnów area (southern Poland). Microflora associations (Acritarcha) recognised in the clayey and silt deposit (metaargillites and metaaleurolites) in Zalasowa 1 and Stawiska I boreholes indicate the Precambrian age. The results of the structural studies of the Precambrian erosion surface show its significant displacement and differentiation in terms of the depth of its occurrence. In the southern part of the area studied, between Brzozowa I, Zakliczyn I and Siekierczyna 1G 1 boreholes, a displacement zone appears. It is interpreted as a SE prolongation of the Lubliniec-Kraków-Rajbrot displacement zone which separates two main tectonic elements of Upper Silesis block and Małopolska block. The thrust of the consolidated basement of the Rajbrot-Siekierczyna block (which is included to Upper Silesian block) is probably about 2-3 km in relation to the basement of Zakliczyn-Brzozowa area (which belongs to Małopolska block).

13

The Ordovician acritarchs of the Pomeranian Caledonides and their foreland - similarities and differences

Szczepanik Z.

Geological Quarterly

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2000

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Vol. 44, Nr 3

275-295

EN

Ordovician acritarch assemblages of the West Pomeranian Caledonides and their platformal foreland in the Peribaltic Syneclise immediately adjoining the T-T Zone were investigated. Material come from the Ordovician section of the Kościerzyna IG 1, Lębork IG 1 and Gdańsk IG 1 boreholes drilled in the marginal part of the East European Craton, though acritarchs were found only in two samples from the Gdańsk IG 1 borehole. In general, microflora was abundant and the investigations supported current ideas on the stratigraphical level of these rocks. The acritarch assemblages from the Gdańsk IG 1 borehole, found at a depth of 3214.8 m, contain species of Baltisphaeridium, characteristic of the Llanvirn and described by Górka from the eastern part of the Peribaltic Syneclise and the Podlasie Depression. The abundant microflora from West Pomerania contains index taxa of the uppermost Llanvirn (Llandeilo) and Caradoc. Numerous palynomorph associations from the Ordovician rocks of the Koszalin-Chojnice Zone can be divided into three local microfloral zones, using quantitative data, and these may be useful for local stratigraphical correlations. Acritarch assemblages on either side of the T-T Zone show many similarities and suggest that, in the late Llanvirn and Caradoc, there was little palaeogeographic separation between the sedimentary basins of Baltica and West Pomerania; at least, their palaeolatitudinal positions were similar. The thermal maturity of Ordovician organic matter (low and moderate) is also similar in both these areas. The highest heat flow values seem to be characteristic of the western part of the Peribaltic Syneclise, adjoining the T-T Zone. The degree of their thermal alterations in the West Pomeranian Caledonides is surprisingly low when the strong tectonic deformation and considerable depth of the Ordovician rocks are taken into account. The high morphological diversity of the acritarch assemblages, the presence of Baltisphaeridium and Ordovicidium, and especially of abundant Veryhachium, suggest that microflora from the Koszalin-Chojnice Zone represents an open-marine depositional palaeoenvironment, distant from the coast.

14

The Cambrian of the western part of the Pomeranian Caledonides foreland, Peribaltic Syneclise : microfloral evidence

Szczepanik Z.

Geological Quarterly

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2000

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Vol. 44, Nr 3

261-273

EN

This paper describes the microfloral succession in Cambrian deposits in the Kościerzyna IG 1 and Gdańsk IG 1 boreholes drilled in the western part of the Peribaltic Syneclise, immediately adjoining the T-T Zone in the Pomeranian Caledonides foreland. Both these boreholes have yielded abundant acritarch assemblages that allow the partial zonation of the Lower and Middle Cambrian deposits. The Cambrian deposits of the Kościerzyna IG 1 borehole comprise the following microfloral zones: Asteridium tornatum-Comasphaeridium velvetum, Skiagia ornata-Fimbriaglomerella membranacea and Heliosphaeridium dissimilare-Skiagia ciliosa. The Volkovia dentifera-Liepaina plana Zone may also be present. The Acadoparadoxides pinus Zone (upper part of the A. oelandicus Superzone), well documented by trilobites, might correlate with the Cristallinium cambriense-Eliasum Superzone. This conflicts with the findings of Jankauskas and Lendzion (1992), who restricted the range of the commonly occurring C. cambriense (Slavikova) only to the Paradoxides paradoxissimus Superzone and younger deposits. The Lower Cambrian Skiagia-Fimbriaglomerella and (or) Heliosphaeridium-Skiagia Zones have been documented in the Gdańsk IG 1 borehole. As in the Kościerzyna IG 1 borehole, abundant Middle Cambrian acritarchs of the C. cambriense-Eliasum Superzone define the presence of rocks not older than equivalents of the A. pinus Zone. Palynomorphs from the Kościerzyna IG 1 borehole correspond to stage 6 of the AMOCO thermal alteration scale, i.e. to palaeotemperatures considerably exceeding 100°C. The maximum palaeotemperature of the Cambrian rocks at Gdańsk has not exceeded 100°C.

15

Stratigraphic position of acritarchs from the lowermost Ordovician of the Holy Cross (Góry Świętokrzyskie) Mts in the light conodonts studies

Bednarczyk W.

Bulletin of the Polish Academy of Sciences. Earth Sciences

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1998

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Vol. 46, nr 1

1-8

EN

Conodont described by the present author form chalcedonites of the Zbilutka Member, the lower unit of the Międzygórz Formation in the Holy Cross (Góry Świętokrzyskie) Mts, Poland, indicate an Upper Tremadocian age of this member. The conodont assemblage represents the Drepanoistodus deltifer pristinus Subzone which is characteristic for the Late Tremadocian Varangu stage in Estonia. The conodont dating here proposed allows to determine the Lated Tremadocian age of acritarch assemlages previously described by various authors from the same strata.