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

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:Gyrochorteisp.,Ophiomorpha nodosaLundgren, 1891,Ophiomorphaisp.,Phycodescf.curvipalmatum(Pollard, 1981), ?Phycodesisp.,Planolitescf.beverleyensis(Billings, 1862),Thalassinoides paradoxicusWoodward, 1830 and ?Thalassinoidesisp. Moreover, interesting compound burrow systems, here referred to asThalassinoides-Phycodescf.palmatusand ?Thalassinoides-Phycodes, were recognised at the Czaple Quarry. Additionally, ?Gyrochorteisp.,Phycodescf.flabellum(Miller and Dyer, 1878) and ?Treptichnusisp. 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 gastropodNerinea bicinctaBronn, 1836 and the bivalveLima 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,Gyrochorteand ?Treptichnus). The assemblage of trace fossils is characteristic of theSkolithosichnofacies andCruzianaichnofacies, 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.

Trace fossils and depositional environments of the middle Turonian sandstones in the Upper Nysa Kłodzka Graben (Sudetes, Poland) revisited

“…Niebuhr and Wilmsen, 2016). The trace fos sils stud ied have also been re ported from other Up per Cre ta ceous suc ces sions (up per Turonian-Coniacian) from the bas ins cited (Mikuláš, 2006;Leszczyñski, 2010Leszczyñski, , 2018Chrz¹stek and Wypych, 2018;Chrz¹stek, 2020).…”

“…Dur ing the early mid dle Turonian, quiet pelitic sed i men ta tion was in terrupted by tec tonic block move ments that af fected the source area and ba sin floor (East Sudetic Is land; cf. Jerzykiewicz and Wojewoda, 1986;Wojewoda, 1997;Biernacka and Józefiak, 2009;Chrz¹stek and Wojewoda, 2011). Ero sion in the source area pro duced large amounts of coarse clastic ma te rial, which was trans ported to the Up per Nysa K³odzka Palaeobasin and depos ited in elon gated de pres sions, bor dered by fault es carpments, form ing gi ant foresets, i.e.…”

Not simply volcanoes – The Geoheritage of the Cretaceous System in the Land of the Extinct Volcanoes Geopark, West Sudetes (SW Poland)

“…The height of vertical quarry walls locally exceeds 20 m, allowing for tracing various structural features of the sandstone series, such as northerly dip of 10-14°, thick bedding up to 4 m and regular jointing pattern, with two vertical sets trending NE-SW and NW-SE (Kowalski A., n.d.). Closer inspection of abandoned sandstone blocks and slabs may reveal various trace fossils and casts of molluscs (Chrząstek & Wypych, 2018), as well as ripples and slickensides, the latter related to the proximity of the Jerzmanice Fault. A picturesque double stone bridge at the entrance to one disused quarry, dated back to the late 19 th century, is a local landmark and an example of industrial heritage.…”

Sedimentation in a synclinal shallow‐marine embayment: Coniacian of the North Sudetic Synclinorium, SW Poland

“…The modern stratigraphic and palaeoenvironmental framework for the basin was developed by Milewicz (1956Milewicz ( , 1965Milewicz ( , 1966Milewicz ( , 1973Milewicz ( , 1985Milewicz ( , 1997Milewicz ( , 2006 and Milewicz et al (1968), with subsequent contributions by Walaszczyk (2008), Leszczyński (2010Leszczyński ( , 2018 and Chrząstek and Wypych (2018). Particularly important was the recognition by Milewicz (1956) of a hiatus between the Rakowice Wielkie Formation and the Czerna Formation in the southeastern part of the basin (Figure 2), attributed to a northwesterly retreat of the sea from a large part of the basin and erosion in this emerged area.…”