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The pre-Taghanic (Givetian, Middle Devonian) ecosystems of Miłoszów (Holy Cross Mts, Poland)

Halamski Adam T., Baliński Andrzej, Racki Grzegorz, Amler Michael R. W., Basse Martin, Denayer Julien, Dubicka Zofia, Filipiak Paweł, Kondas Marcelina, Krawczyński Wojciech, Mieszkowski Radosław, Narkiewicz Katarzyna, Olempska Ewa, Wrzołek Tomasz, Wyse-Jacson Patrick N., Zapalski Mikołaj K., Zatoń Michał, Kozłowski Wojciech

Annales Societatis Geologorum Poloniae

2022

Vol. 92, No. 4

323--379

The middle and upper parts of the Skały Fm, Early to Middle Givetian in age, were investigated in four sections at Miłoszów Wood in the Łysogóry Region (northern region of the Holy Cross Mountains, central Poland). The dating is based on conodonts (Polygnathus timorensis Zone to the later part of the Polygnathus varcus/Polygnathus rhenanus Zone; early Polygnathus ansatus Zone cannot be excluded) and spores (Ex1–2 subzones) and, coupled with cartographic analysis and geophysical investigation, allows correlation within the strongly faulted succession. Significant lateral facies variations within the carbonate ramp depositional system in comparison with the better studied Grzegorzowice–Skały section, about 3 km distant, are documented, thanks to conodont-based correlation of both successions. Foraminifers, fungi, sponges, rugose and tabulate corals, medusozoans, microconchids and cornulitids, polychaetes (scolecodonts), molluscs (bivalves, rostroconchs, and gastropods), arthropods (trilobites and ostracods), bryozoans, hederelloids, ascodictyids, brachiopods, echinoderms (mostly crinoids, rare echinoids, holuthurians, and ophiocistoids), conodonts, fish, plants (prasinophytes, chlorophycophytes, and land plant spores), and acritarchs are present. Brachiopods are the most diverse phylum present (68 species), other richly represented groups are bryozoans and echinoderms; in contrast, cephalopods and trilobites are low in diversity and abundance. The muddy, middle to outer ramp biota (200 marine taxa, including 170 species of marine animals, 22 photoautotrophs, 6 forams) represents a mixture of allochthonous shallower-water communities (upper BA3), including storm- and possibly tsunami-affected coral mounds, and autochthonous deep-water soft-bottom brachiopod (e.g., Bifida–Echinocoelia) communities (BA 4–5). The richness and diversity of the Miłoszów biota is relatively high, comparable with other approximately coeval pre-Taghanic ecosystems during the Devonian climatic deterioration (cooling). Preliminary data indicate that in the Holy Cross Mountains, no large-scale replacement of brachiopod (and probably many other benthic ones, like crinoids) communities took place between the Early–Middle Givetian and the Early Frasnian, in contrast to the demise of the Hamilton/Upper Tully fauna in the Appalachian Basin. Such a similarity of pre- and post-Taghanic faunas does not exclude the occurrence of environmental perturbations and transient community turnovers, caused by immigrations during the Taghanic Biocrisis, but evidences the successful recovery of the indigenous biota.

The K-Pg boundary section at Nasiłów, Poland : stratigraphic reassessment based on foraminifers, dinoflagellate cysts and palaeomagnetism

Remin Zbyszek, Cyglicki Michał, Barski Marcin, Dubicka Zofia, Roszkowska-Remin Joanna

Geological Quarterly

2021

Vol. 65, No. 3

art. no. 45

The Nasiłów section represents the uppermost part of the Middle Vistula River section, a classical Polish extra-Carpathian Cretaceous section, and gives access to the Cretaceous-Paleogene (K-Pg) boundary interval. Despite many papers that have been published so far, our newly collected data shed new light on the completeness of biostratigraphic and sedimentary records of the K-Pg at that site. The Nasiłów section encompasses the upper Maastrichtian regional XII and XIII foraminiferal assemblage zones and the lower Danian P0?-Pα standard planktonic foraminiferal zones. The K-Pg boundary is placed at the top of a phosphatic layer. The grey marly chalk unit, never before subjected to examination of biostratigraphically important taxa, displays blooms of guembelitrids pointing to the uppermost Maastrichtian (XIII foraminiferal assemblage Zone) as well as of planktonic and benthic foraminifers of a reduced test size. Such foraminiferal dwarfism is commonly observed near the end of the Cretaceous and interpreted as a response to the Deccan volcanism (possible 2nd phase) that caused climate changes and ocean acidification. The terminal Maastrichtian age of the marly chalk unit is additionally supported by an acme of the dinoflagellate cyst Palinodinium grallator, together with Tallasiphora pelagica and Disphaerogena carposphaeropsis. The “Greensand”, a distinct glauconite-quartz sand unit, contains exclusively terminal Maastrichtian planktonic foraminifers and dinoflagellate cyst assemblages. Individual specimens of Danian age are interpreted to be either an effect of contamination or were translocated down by burrowers into the Greensand. The lowermost portion of the Siwak (informal lithostratigraphic unit) demonstrates an early Danian age based on the co-occurrence of the common planktonic foraminifers Globoconusa daubjergensis, Guembelitria cretacea, Muricohedbergella monmouthensis, M. planispira, Planoheterohelix globulosa, Parvularuglobigerina extensa and P. alabamensis. The last occurrence of Palynodinium grallator and the first occurrences of Carptella cornuta and Senoniasphaera inornata, recorded directly above the phosphatic layer, support the same age assignment. The new palaeomagnetic data cannot prove remagnetization at the boundary interval, in contrast to previous research which gave support to a hiatus in the critical interval.

The evolution of the Carpathian Foredeep Basin during the latest Badenian and Sarmatian (Middle Miocene) : inferences from micropalaeontological data

Dumitriu Simina Dumitriţa, Dubicka Zofia, Loghin Sergiu, Melinte-Dobrinescu Mihaela Carmen, Paruch-Kulczycka Jolanta

Geological Quarterly

2020

Vol. 64, No. 4

1004--1022

Seven Middle Miocene (Upper Badenian to Lower Sarmatian) sedimentary sections of the Central Paratethys, two from the Polish Carpathian Foredeep Basin (PCFB) and five from the Eastern Carpathian Foreland Basin (ECFB) of Romania and the Republic of Moldova have been analysed micropalaeontologically to better constrain the Badenian-Sarmatian Extinction Event, characterized by significant taxonomic impoverishment of both foraminifers and ostracods. Our studies show significant palaeoenvironmental changes in the basin including depth, salinity, oxygenation, and organic matter flux. The occurrence of moderately diverse planktonic foraminifera (Globigerina, Globigerinita, Globorotalia, Trilobatus, Orbulina, Velapertina) in the Upper Badenian deposits of the PCFB as well as in the ECFB and their rarity in the lowermost Sarmatian indicate an almost fully marine environment during the latest Badenian, followed by a significant regression and possible appearance of much more restricted marine conditions across the boundary. The taxonomic composition of the Sarmatian foraminifera, ostracoda and calcareous nannofossils indicate that during this interval the salinity fluctuated strongly, with the water regime varying from brackish to normal marine. In addition, the identified micropalaeontological assemblages identified show palaeoenvironmental similarity across different basins of the Central Paratethys. This supports a hypothesis of possible connections during the latest Badenian between different areas of the Central Paratethys, as well as of the existence of a gateway between the Central Paratethys and the Mediterranean realm.