<abstract xmlns="http://www.w3.org/1999/xhtml"><p>The Coniacian quartz sandstones (Żerkowice Member, Rakowice Wielkie Formation) that crop out at quarries near Czaple-Nowa Wieś Grodziska (North Sudetic Synclinorium) contain a low-diversity assemblage of trace fossils: <italic>Gyrochorte</italic> isp., <italic>Ophiomorpha nodosa</italic><xref ref-type="bibr" rid="j_logos-2018-0003_ref_102_w2aab3b7b3b1b6b1ab1ad102Aa">Lundgren, 1891</xref>, <italic>Ophiomorpha</italic> isp., <italic>Phycodes</italic> cf. <italic>curvipalmatum</italic> (<xref ref-type="bibr" rid="j_logos-2018-0003_ref_145_w2aab3b7b3b1b6b1ab1ad145Aa">Pollard, 1981</xref>), ?<italic>Phycodes</italic> isp., <italic>Planolites</italic> cf. <italic>beverleyensis</italic> (<xref ref-type="bibr" rid="j_logos-2018-0003_ref_015_w2aab3b7b3b1b6b1ab1ac15Aa">Billings, 1862</xref>), <italic>Thalassinoides paradoxicus</italic><xref ref-type="bibr" rid="j_logos-2018-0003_ref_198_w2aab3b7b3b1b6b1ab1ad198Aa">Woodward, 1830</xref> and ?<italic>Thalassinoides</italic> isp. Moreover, interesting compound burrow systems, here referred to as <italic>Thalassinoides</italic>-<italic>Phycodes</italic> cf. <italic>palmatus</italic> and ?<italic>Thalassinoides</italic>-<italic>Phycodes</italic>, were recognised at the Czaple Quarry. Additionally, ?<italic>Gyrochorte</italic> isp., <italic>Phycodes</italic> cf. <italic>flabellum</italic> (<xref ref-type="bibr" rid="j_logos-2018-0003_ref_122_w2aab3b7b3b1b6b1ab1ad122Aa">Miller and Dyer, 1878</xref>) and ?<italic>Treptichnus</italic> isp. were encountered at correlative levels in the Rakowice Małe Quarry. Some of these ichnotaxa have not been recorded previously from Coniacian sandstones of the Żerkowice Member. Additionally, in slabs of these sandstones, the gastropod <italic>Nerinea bicincta</italic><xref ref-type="bibr" rid="j_logos-2018-0003_ref_020_w2aab3b7b3b1b6b1ab1ac20Aa">Bronn, 1836</xref> and the bivalve <italic>Lima haidingeri</italic><xref ref-type="bibr" rid="j_logos-2018-0003_ref_203_w2aab3b7b3b1b6b1ab1ad203Aa">Zittel, 1866</xref> were found. These interesting finds, in particular the gastropods, were already noted from the study area in the first half of the twentieth century by <xref ref-type="bibr" rid="j_logos-2018-0003_ref_160_w2aab3b7b3b1b6b1ab1ad160Aa">Scupin (1912–1913)</xref>. Ethologically, the trace fossil assemblage is represented by domichnia or domichnia/fodinichnia (<italic>Ophiomorpha</italic>, <italic>Thalassinoides</italic>), fodinichnia (<italic>Phycodes</italic>) and pascichnia (<italic>Gyrochorte</italic>, <italic>Planolites</italic>). The compound burrow systems (<italic>Thalassinoides</italic>-<italic>Phycodes</italic>) are interpreted as dwelling/feeding structures. The possible tracemakers are crustaceans (<italic>Ophiomorpha</italic>, <italic>Thalassinoides</italic>) or worm-like animals (annelids and other) (<italic>Planolites</italic>, ?<italic>Phycodes</italic>, <italic>Gyrochorte</italic> and ?<italic>Treptichnus</italic>). The assemblage of trace fossils is characteristic of the <italic>Skolithos</italic> ichnofacies and <italic>Cruziana</italic> ichnofacies, typical of shallow-marine settings. Ichnological studies, as well as the presence of accompanying fossils (bivalves, gastropods), confirm the palaeoenvironmental reconstruction of the Żerkowice Member sandstones by <xref ref-type="bibr" rid="j_logos-2018-0003_ref_100_w2aab3b7b3b1b6b1ab1ad100Aa">Leszczyński (2010)</xref>. That author interpreted the Coniacian sandstones as bar and storm deposits laid down in a shallow epicontinental sea (mainly the foreshore-upper shoreface; up to the middle shoreface) under normal oxygenation and salinity, in soft substrate, above fair-weather wave base. The deposition of the Żerkowice Member sandstones is linked to a regression that started after uplift of the southeastern part of the North Sudetic Synclinorium.</p></abstract>

The Coniacian quartz sandstones (Żerkowice Member, Rakowice Wielkie Formation) that crop out at quarries near Czaple-Nowa Wieś Grodziska (North Sudetic Synclinorium) contain a low-diversity assemblage of trace fossils: Gyrochorte isp., Ophiomorpha nodosaLundgren, 1891, Ophiomorpha isp., Phycodes cf. curvipalmatum (Pollard, 1981), ?Phycodes isp., Planolites cf. beverleyensis (Billings, 1862), Thalassinoides paradoxicusWoodward, 1830 and ?Thalassinoides isp. Moreover, interesting compound burrow systems, here referred to as Thalassinoides-Phycodes cf. palmatus and ?Thalassinoides-Phycodes, were recognised at the Czaple Quarry. Additionally, ?Gyrochorte isp., Phycodes cf. flabellum (Miller and Dyer, 1878) and ?Treptichnus isp. were encountered at correlative levels in the Rakowice Małe Quarry. Some of these ichnotaxa have not been recorded previously from Coniacian sandstones of the Żerkowice Member. Additionally, in slabs of these sandstones, the gastropod Nerinea bicinctaBronn, 1836 and the bivalve Lima haidingeriZittel, 1866 were found. These interesting finds, in particular the gastropods, were already noted from the study area in the first half of the twentieth century by Scupin (1912–1913). Ethologically, the trace fossil assemblage is represented by domichnia or domichnia/fodinichnia (Ophiomorpha, Thalassinoides), fodinichnia (Phycodes) and pascichnia (Gyrochorte, Planolites). The compound burrow systems (Thalassinoides-Phycodes) are interpreted as dwelling/feeding structures. The possible tracemakers are crustaceans (Ophiomorpha, Thalassinoides) or worm-like animals (annelids and other) (Planolites, ?Phycodes, Gyrochorte and ?Treptichnus). The assemblage of trace fossils is characteristic of the Skolithos ichnofacies and Cruziana ichnofacies, typical of shallow-marine settings. Ichnological studies, as well as the presence of accompanying fossils (bivalves, gastropods), confirm the palaeoenvironmental reconstruction of the Żerkowice Member sandstones by Leszczyński (2010). That author interpreted the Coniacian sandstones as bar and storm deposits laid down in a shallow epicontinental sea (mainly the foreshore-upper shoreface; up to the middle shoreface) under normal oxygenation and salinity, in soft substrate, above fair-weather wave base. The deposition of the Żerkowice Member sandstones is linked to a regression that started after uplift of the southeastern part of the North Sudetic Synclinorium.

Coniacian sandstones from the North Sudetic Synclinorium revisited: palaeoenvironmental and palaeogeographical reconstructions based on trace fossil analysis and associated body fossils

Geologos

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

The Coniacian quartz sandstones (Żerkowice Member, Rakowice Wielkie Formation) that crop out at quarries near Czaple-Nowa Wieś Grodziska (North Sudetic...

Coniacian sandstones from the North Sudetic Synclinorium revisited: palaeoenvironmental and palaeogeographical reconstructions based on trace fossil analysis and associated body fossils

Publié en ligne: 17 mai 2018

Pages: 29 - 53

Reçu: 08 mai 2017

Accepté: 05 mars 2018

DOI: https://doi.org/10.2478/logos-2018-0003

Mots clés
ichnology, Upper Cretaceous, Sudetes Mountains, Żerkowice Member, foreshore, shoreface

© 2018 Alina Chrząstek et al., published by De Gruyter Open

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

Coniacian sandstones from the North Sudetic Synclinorium revisited: palaeoenvironmental and palaeogeographical reconstructions based on trace fossil analysis and associated body fossils

Publié en ligne: 17 mai 2018

Pages: 29 - 53

Reçu: 08 mai 2017

Accepté: 05 mars 2018

DOI: https://doi.org/10.2478/logos-2018-0003

Mots clésichnology, Upper Cretaceous, Sudetes Mountains, Żerkowice Member, foreshore, shoreface

© 2018 Alina Chrząstek et al., published by De Gruyter Open

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

Mots clés
ichnology, Upper Cretaceous, Sudetes Mountains, Żerkowice Member, foreshore, shoreface