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A new Danian echinoid assemblage from the Greensand in the Kazimierz Dolny area, central Poland: taxonomy, taphonomy and sedimentological implications

Machalski M., Jagt J. W. M.

Acta Geologica Polonica

2018

Vol. 68, no. 4

571--596

We describe a new echinoid assemblage, composed of specimens of Bolbaster sp., Cyclaster danicus (Schlüter, 1897), Diplodetus vistulensis (Kongiel, 1950) and Linthia? sp. in a distinctive phosphatic preservation, from the so-called Greensand, a marly glauconitic sandstone horizon at the base of the Danian succession in the Kazimierz Dolny area (central Poland). This assemblage presumably is of early Danian age, with Cyclaster danicus occurring in the lower Danian of Denmark and southern Sweden. The specimens are preserved as internal moulds, composed of phosphatised glauconitic sandstone, occasionally with some test material adhering. The genesis of these moulds involved the following steps: (1) infilling of tests of dead echinoids with glauconitic sand; (2) penetration of the infills by coelobiotic deposit-feeding organisms that produced burrows along the inner test surface; (3) early-diagenetic cementation of infills by calcium phosphate; and (4) exhumation and intraformational reworking of specimens, leading to abrasion, fragmentation and loss of test material in some individuals. Co-occurring are unphosphatised moulds of Echinocorys ex gr. depressa (von Eichwald, 1866) and Pseudogibbaster cf. depressus (Kongiel in Kongiel and Matwiejewówna, 1937), which may represent a younger (middle to late Danian) assemblage. Additionally, the presence of derived late Maastrichtian echinoids, e.g., Temnocidaris (Stereocidaris) ex gr. herthae (Schlüter, 1892), Pleurosalenia bonissenti (Cotteau, 1866) and Hemicara pomeranum Schlüter, 1902, is confirmed for the Greensand, based on new material and re- examination of previously recorded specimens. In summary, members of three echinoid assemblages of different age and preservation occur together in the Greensand. Our results are compatible with former interpretations of this unit as a condensed, transgressive lag with mixed faunas of different age and provenance. However, they are incompatible with the hypothesis that phosphatised Danian fossils preserved in the Greensand are derived from a facies equivalent, now gone, of the lower Danian Cerithium Limestone in eastern Denmark, because all moulds are composed of phosphatised glauconitic sandstone that is utterly different from the calcareous dinocyst-dominated, fine crystalline matrix of the Cerithium Limestone.

Selected geosites of Cretaceous deposits in Central and Eastern Poland

Walaszczyk I., Cieśliński S., Sylwestrzak H.

Polish Geological Institute Special Papers

1999

Vol. 2

71-76

Eight proposed Cretaceous geosite candidates, from the area of Central and Eastern Poland, are shortly characterized. They include: waterfalls on the Szum, Sopot, Jeleń, and Tanew rivers, exposures of Albian sandstones near Nagórzyce, Dobromierz brachyanti-cline, Opoczka quarries, Janików quarries, and abandoned quarries of Piotrawin, Kazimierz, Bochotnica, and Nasiłów. Five latter exposures, located along the middle section of the Vistula river, give an access to the famous middle Vistula section, representing a key section to the Upper Cretaceous succession in this part of Europe, being a site of an outstanding scientific importance. Of high scientific value are also other of the proposed sites. The waterfalls on the Tanew river represent, moreover, a unique landscape, which may also be of a great interest due to recreation and tourist reasons.

Scharakteryzowano osiem wybranych stanowisk przyrody nieożywionej w utworach kredy z obszaru Polski środkowej i wschodniej. Wśród proponowanych obiektów znalazły się: progi kredowe na rzekach Szum, Sopot, Jeleń i Tanew, odsłonięcie piaskowców albskich koło Nagórzyc, brachyantyklina Dobromierza, kamieniołomy w Opoczce, kamieniołomy w Janikowie oraz odsłonięcia w Piotrawinie, Kazimierzu Dolnym, Bochotnicy i w Nasiłowie. Pięć ostatnich wymienionych odsłonięć znajduje się na obszarze tzw. górnokredowego profilu środkowej Wisły, dostarczającego standardowego profilu kredy górnej w tej części Europy. Jest to obszar o wyjątkowym znaczeniu w badaniach facjalnych, stratygraficznych oraz paleontologicznych górnej kredy. W skali regionu istotne są oczywiście również i pozostałe proponowane miejsca. Progi wodospadowe na rzece Tanew reprezentują ponadto unikalną formę krajobrazową w tej części kraju i mają duże znaczenie jako obiekt turystyczno-rekreacyjny.