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Middle Devonian Skały Formation in the Holy Cross Mountains (Poland) : formal description and subdivision based on new field data

Racki Grzegorz, Wójcik Krystian, Halamski Adam T., Narkiewicz Marek

Annales Societatis Geologorum Poloniae

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2022

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Vol. 92, No. 4

425--444

EN

The well-known fossiliferous and lithologically variable clay-carbonate series in the Łysogóry Region (northern part of the Holy Cross Mts, central Poland), enclosed between the Middle Devonian Amphipora dolomites and limestones (Kowala Formation) and siliciclastics (Świętomarz Beds), is defined formally as the Shaly-Calcareous Skały Formation. This Upper Eifelian to Middle Givetian, ca. 250–280 m thick unit, consists of marly and clay shales, interbedded many times with various limestone types (including encrinite and biohermal varieties), as well as with marls and siltstones. Its diagnostic feature is the presence of variable skeletal accumulations, formed by exceptionally numerous, well-preserved and diverse macrofauna (including brachiopods, corals, crinoids, bryozoans), described since the 19th century. The stratotype is located in the eastern slope of the Dobruchna stream near the Skały village and belongs to the Silurian to Upper Devonian Grzegorzowice-Skały section. Compared to the previously used term, Skały Beds sensu Pajchlowa (1957), the lower boundary is redefined, owing to a new exposure in the active Skała Quarry, and placed higher, at the base of the famous brachiopod shales (set XIV of Pajchlowa), instead of the formerly accepted lower boundary at the base of set XIII. Set XIV is formally distinguished as the Dobruchna Brachiopod Shale Member. The higher part of the Skały Fm (sets XV–XXVA) is not subdivided further, as the poorly exposed succession, including in particular the type area, precludes a more accurate recognition of lithological variability. The upper boundary of the Skały Fm is placed at the top of set XXV sensu Pajchlowa (1957), corresponding to the boundary between subsets XXVA and XXVB sensu Malec and Turnau (1997). A hypostratotype of the upper boundary is selected in the outcrop M0 at Miłoszów, 2.5 km westwards from the type section, allowing recognition of the diachroneity of lithological change defining the transition from the Skały Fm to Świętomarz Beds. A borehole situated in a key location would be an obvious next step in the further elucidation of the stratigraphic sequence of the Łysogóry Region.

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Middle Devonian biota and environments of the Łysogóry Region (Poland) : Introduction

Halamski Adam T.

Annales Societatis Geologorum Poloniae

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2022

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Vol. 92, No. 4

317--321

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Habitats in the Pre-Taghanic (Givetian, Middle Devonian) muddy carbonate ramp at Miłoszów (Holy Cross Mountains, Poland) : geochemical and microfacies evidence

Pisarzowska Agnieszka, Racki Grzegorz, Rakociński Michał

Annales Societatis Geologorum Poloniae

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2022

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Vol. 92, No. 4

381--409

EN

The well-known fossiliferous and lithologically variable Middle Devonian Shaly-Calcareous Skały Formation in the Łysogóry Region (northern part of the Holy Cross Mountains, central Poland) was studied for the first time in terms of elemental geochemistry, carbon isotope stratigraphy and limestone microfacies. Three Lower to Middle Givetian marly-limestone successions, exposed at Miłoszów, represent middle to outer facies belts of the vast carbonate ramp, characterized by very rich epifaunal and infaunal benthic life in muddy, oxic, eutrophic, and photic zone habitats. Brachiopods and occasionally corals (in mesophotic association), erect branching bryozoans, and tiny crinoids played a leading role among flourishing sessile suspension-feeders. High-energy storm events, possibly even a tsunami, during the brief Early Givetian time strengthened a prolific carbonate ooze delivery system from shallow ramp areas, including restricted back-ramp lagoons and a variety of organic buildups, populated by corals and stromatoporoids. The ecologically mixed skeletal grain association is characterized by the rich occurrence of a typical lagoonal biota, calcispheres and amphiporoids. The effective carbonate factory declined stepwise regionally during the Middle Givetian because of an intermittent progradation of the deltaic system of the Świętomarz Beds, linked with climate cooling and the activation of block movements. The regional carbonate crisis resulted in the demise of diverse benthic life, including the prolific calcified microbiota. The higher Skały Formation succession, deposited between the important Kačák and Taghanic bioevents, is noticeable for a background carbon-isotope pattern in carbonate and organic matter signatures, with the baseline with the baseline δ13 Ccarb values between 1‰ and 2‰. The microfacies and chemostratigraphic data confirm that at least the lower pumilio bioevent was not recorded in the Łysogóry Region.

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A new Middle Devonian (Givetian) psammosteid (Vertebrata : Heterostraci) from Poland

Dec Marek

Annales Societatis Geologorum Poloniae

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2020

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Vol. 90, No. 1

75--93

EN

A new genus and species of psammosteid heterostracan, Psarkosteus mediocris gen. et sp. nov., is described from the Middle Devonian (Givetian) of the Skały Formation, the Holy Cross Mountains, Poland. The dorsal plate of Psarkosteus is constricted in its anterior part and the postorbital plate is long and narrow. Both features, along with the morphology and variety of tubercles, distinguish it from other representatives of the group. Most distinctive are big, teardrop-shaped tubercles, each with a flat or slightly concave surface and with its tip directed posteriorly, and a crenulated base, located along the branchial plates. The lateral line system in Psarkosteus is similar to that of Drepanaspis gemuendenensis and confirms earlier reconstructions.

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On the erroneous identification of a turiniid thelodont in the Middle/Upper Devonian boundary beds of the Middle Urals

Märss T., Ivanov A.

Acta Geologica Polonica

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2018

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Vol. 68, no. 3

455

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Middle Devonian conodonts and structural implications for Świętomarz : Śniadka section (Holy Cross Mountains)

Woroncowa-Marcinowska T.

Annales Societatis Geologorum Poloniae

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2012

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Vol. 82, No. 4

349–-360

EN

The paper presents a new interpretation of the geological structure and stratigraphy of the Devonian in the Świętomarz–Śniadka section. The uppermost Śniadka Formation (equivalent to the Nieczulice Formation), was described previously from the northern part of the section between exposures of the sandstones and shales of the Świętomarz Formation. The present study revealed the presence in the mentioned area of Sitka Coral-Crinoid Limestone Member and the Sierżawy Member, referable to the Skały Formation. Black, thin-bedded limestones, occurring here, were assigned to the upper part of the Sierżawy Member. Conodont assemblages indicate that the Sitka Coral-Crinoid Limestone Member corresponds to the hemiansatus Zone, whereas most of the Sierżawy Member represents the timorensis – rhenanus/varcus zones. The presence of the North American species Icriodus janaea is documented for the first time in Poland. Clay shales and marls with Maenioceras terebratum are considered to be the uppermost part of the Sierżawy Member. These stratigraphic data are the basis for a new interpretation of the geological structure of the Bodzentyn Syncline.

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Biostratygrafia konodontowa dewonu środkowego obszaru radomsko-lubelskiego

Narkiewicz K.

Prace Państwowego Instytutu Geologicznego

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2011

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T.196

147--192

PL

Praca jest syntezą wcześniejszych, publikowanych wyników badań konodontowych dewonu środkowego obszaru radomsko-lubelskiego uzupełnionych o nowe dane z czterech wierceń. Ogółem przeanalizowano 10 profili wiertniczych i 169 próbek, w tym 92 pozytywne, z których uzyskano łącznie około 1600 okazów konodontów. W badanej kolekcji wyróżniono 10 rodzajów i 41 taksonów w randze gatunków i podgatunków, z których 10 znaleziono w Polsce po raz pierwszy. Szereg oznaczeń taksonomicznych i wiekowych zweryfikowano lub ustalono na podstawie nowych obserwacji. Analizowane konodonty należą głównie do biofacji płytkomorskich, zdominowanych przez rodzaje Polygnathus i Icriodus. Dlatego, w analizie biostratygraficznej nie zastosowano zonacji „standardowej” opartej na formach głębokowodnych i (lub) otwartomorskich, ale posłużono się podziałami alternatywnymi. Umożliwiło to wydzielenie 10 poziomów i podpoziomów konodontowych, aczkolwiek w szeregu przypadków możliwe było jedynie szerokie określenie wieku osadów. Zintegrowane dane makro- i mikrofaunistyczne oraz sporowe pozwoliły na identyfikację pięter eifel i żywet oraz podpięter żywetu. Dokładniejsze ustalenie granic chronostratygraficznych było możliwe w przypadku granicy emsu z eiflem, żywetu z franem oraz granic podpięter żywetu: dolnego/środkowego i środkowego/górnego. We wszystkich badanych profilach uzyskane dane pozwoliły na sprecyzowanie chronostratygrafii, która dotychczas była oparta głównie na makrofaunie o szerokich zasięgach wiekowych.

EN

The paper is a synthesis of previously published results of conodont studies of the Middle Devonian in the Radom–Lublin area, supplemented with new data from four boreholes. Altogether, the study was based on 10 borehole sections and 169 samples, including 92 positive from which ca. 1600 specimens have been obtained. The collected material was assigned to 10 genera and 41 taxa of species and subspecies rank, including 10 found for the first time in Poland. Several previous taxonomic and age determinations were verified or established again based on new observations. The analysed forms belong mainly to shallow-marine biofacies dominated by genera Polygnathusa and Icriodus. Therefore, it was hardly possible to apply the “standard” zonation based on deeper-water/open marine taxa and alternative zonations were used instead. This allowed to distinguish 10 zones and subzones, although in several cases only broad age determinations were possible. Integration of the present conodont results with other micro- and macrofaunal as well as palynostratigraphic data allowed to identify the Eifelian and Givetian stages, the latter subdivided into substages. A more precise dating of lithostratigraphic boundaries was possible in the case of the Emsian/Eifelian and Givetian/Frasnian boundaries as well as the Lower/Middle and Middle/Upper Givetian boundaries. In all the investigated sections the obtained results allowed to constrain chronostratigraphy which was previously based mainly on macrofauna with wide stratigraphic ranges.

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Do partly outdated palaeontological data produce just a noise? An assessment of the Middle Devonian-Mississippian biodiversity dynamics in central Asia on the basis of Soviet-time compilations

Ruban Dmitry A.

Geologos

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2011

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Vol. 17, No. 1

29--47

EN

Interregional tracing of trends and events in the biotic evolution is an important task of modern palaeobiology. In Soviet times (1917-1991), numerous palaeontological data have collected for the territory of Russia and neighbouring U.S.S.R. countries. Later, these data were compiled and published in a series of reference volumes. Although this information cannot be updated in a conventional way, it remains valuable for quantitative analyses, particularly because of its comprehensive and unique character. Assessment of the previously collected data on the stratigraphic distribution of Middle Devonian-Mississippian marine invertebrates in three regions of central Asia (central Kazakhstan, Uzbekistan and Tajikistan) reveals some general patterns of biodiversity dynamics. The total number of genera generally declined during the Givetian-Famennian, whereas a remarkable diversity peak occurred in the Visean. This is consistent with the global pattern and, thus, permits to hypothesize a regional signature of the global trends. Changes in the extinction rate differ, however, between central Asia and the Earth in its entirety, which may be explained particularly by biases in either the regional or the global records. Evidence of the Givetian and Frasnian/Famennian mass extinctions is found in the three regions under study. Results of this tentative study indicate important directions for further research and suggest that central Asia is a highly important domain for studies of mid-Palaeozoic biodiversity dynamics.

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New Late Silurian to Middle Devonian acanthodians of the Timan-Pechora region

Valiukevicius J.

Acta Geologica Polonica

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2003

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Vol. 53, nr 3

209-245

EN

New Pridoli to Eifelian acanthodian scales from various structural units of the Timan-Pechora region are described. Among 15 new species and 1 new genus, there are: 10 new species of nostolepids, common members of most of the biostratigraphic associations, the monospecific genus Monospina gen. nov., a single new species of Cheiracanthoides (all Climatiida), Diplacanthus pechorensis sp. nov. (Diplacanthida), and two new species of Gomphonchus (Ischnacanthida). Besides morphologic descriptions the taxa are also characterised histologically. Acanthodian taxa with scale crowns and bases composed of cellular bone, or very similar tissue, proposed as a primitive feature in their evolution, are reported for the first time.