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Hexactinellid sponge assemblages across the Campanian.Maastrichtian boundary in the Middle Vistula River section, central Poland

Świerczewska-Gładysz E.

Acta Geologica Polonica

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2012

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Vol. 62, no. 4

561-580

EN

The sponge fauna from the Upper Campanian.lowermost Maastrichtian succession of the Middle Vistula River valley (central Poland) is represented mainly by dictyid hexactinellid sponges (Hexactinosida and Lychniscosida). Their greatest abundance and taxonomic variability is noted in the "Inoceramus" inkermanensis Zone (Upper Campanian), and they are less diverse in the overlying (Upper Campanian) Trochoceramus costaecus Zone and lower "Inoceramus" redbirdensis Zone. In the upper "Inoceramus" redbirdensis Zone (basal Maastrichtian in the sense of the Tercis rather than the Boreal definition) they are extremely rare. With the beginning of the Maastrichtian the number of dictyid sponges gradually increases. The observed changes in the abundance and taxonomic variability of the dictyid sponges indicate environmental changes in the latest Campanian.earliest Maastrichtian sea in the area. It seems that changes in basin bathymetry, confined to eustatic sea-level changes in the latest Campanian and early Maastrichtian, were the most important factor. Progressive shallowing of the basin in the latest Campanian drastically restricted the development of dictyids. In the peak regression, the sea level could have fallen to only several tens of metres. The gradual recovery of the sponge assemblages correlates with subsequent deepening of the basin with the start of the Maastrichtian.

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Hexactinellid sponges from the Santonian deposits of the Kraków area (Southern Poland)

Świerczewska-Gładysz E

Annales Societatis Geologorum Poloniae

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2010

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Vol. 80, No 3

253-284

EN

Hexactinellid sponges are extremely abundant in the basal sequence of the Santonian of the Kraków region. This is the only known area in Poland where Santonian deposits with sponges are exposed. The studied sponges are redeposited and probably represent a Santonian or/and Coniacian assemblage. They inhabited a quiet, deeper part of the epicontinental sea that covered the southern part of Poland in Late Cretaceous times. This paper is a taxonomic revision of sponges collected from this region by the late Prof. J. Małecki. Based on existing old collections and newly collected material comprising 1020 specimens, 34 species have been described, including 14 belonging to the Hexactinosida and 20 to the Lychniscosida. All sponge species occurring in the Santonian succession of the Kraków area are also known from various Late Cretaceous sponge assemblages of Europe. Five species described, i.e. Eurete halli (Schrammen), Lefroyella favoidea Schrammen, Spirolophia tortuosa (Roemer), Coeloptychium lobatum Goldfuss, and Wollemannia araneosa Schrammen have not been so far noted in pre-Campanian deposits. The examined assemblage is particularly similar to the sponge fauna from the Middle Coniacian - Middle Santonian deposits of England and from the Lower Santonian of Russia (Saratov area).

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The phosphatized sponges from the Santonian (Upper Cretaceous) of the Wielkanoc Quarry (southern Poland) as a tool in stratigraphical and environmental studies

Olszewska-Nejbert D., Świerczewska-Gładysz E.

Acta Geologica Polonica

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2009

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Vol. 59, no. 4

483-504

EN

Phosphatized sponges from the Santonian of the Wielkanoc Quarry are represented by 11 species of Hexactinosida and 16 species of Lychniscosida. Their species composition is most similar to the Micraster coranguinum Zone fauna (Middle Coniacian - Middle Santonian) of England. Three preservational groups of sponges are distinguished: 'white', 'beige' and 'dark'. They are infilled by phosphatized foraminiferal/foraminiferal-calcisphere wackestone and are contained in the marly calcareous inoceramid packstone. The sponges indicate a calm and relatively deep (> 100 m) life environment. After burial, phosphatization and exhumation, the fossil sponges were redeposited in Upper Santonian strata. The 'white' and 'beige' groups were transported laterally over a very short distance or represent lag deposits. The rolled and crushed sponges of the 'dark' group were exhumed and phosphatized more than once. They could be redeposited (reworked) nearly in the same place and/or transported from some longer distances (but not from outside the Cracow Swell). The phosphatized sponges document the former presence in the area of part of theMiddle Coniacian through Middle Santonian succession, which was removed secondarily by subsequent erosion.

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Late Cretaceous siliceous sponges from the Middle Vistula River Valley (Central Poland) and their palaeoecological significance

Świerczewska-Gładysz E.

Annales Societatis Geologorum Poloniae

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2006

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Vol. 76, No 3

227-296

EN

Siliceous sponges are extremely abundant in the Upper Campanian-Maastrichtian opokas and marls of the Middle Vistula River Valley, situated in the western edge of the Lublin Basin, part of the Cretaceous German-Polish Basin. This is also the only one area in Poland where strata bearing the Late Maastrichtian sponges are exposed. The presented paper is a taxonomic revision of sponges collected from this region. Based both on existing and newly collected material comprising ca. 1750 specimens, 51 species have been described, including 18 belonging to the Hexactinosida, 15 - to the Lychniscosida and 18 - to Demospongiae. Among them, 28 have not been so far described from Poland. One new genus Varioporospongia, assigned to the family Ventriculitidae Smith and two new species Varioporospongia dariae sp. n. and Aphrocallistes calciformis sp. n. have been described. Comparison of sponge fauna from the area of Podilia, Crimea, Chernihov, and Donbas regions, as well as literature data point to the occurrence of species common in the analysed area and to the basins of Eastern and Western Europe. This in turn indicates good connections between particular basins of the European epicontinental sea during the Campanian-Maastrichtian. Analysis of the taxonomic composition of the Middle Vistula assem- blage suggests that the occurring sponge fauna is transitional between the faunas of Eastern and Western Europe, what may be linked with the central location of the Lublin Basin in the European epicontinental sea. The gradual upward decrease of taxonomic diversity of the Hexactinosida and Lychniscosida in the studied succession points to gradual basin shallowing, what is consistent with the global regressive trend by the end of the Cretaceous. The domination of the Hexactinellida over the lithistids in terms of diversity and abundance in the entire section allows us to estimate the maximum depth of the Late Campanian basin as 200-250 m and to constrain the minimum depth during the latest Maastrichtian as about 100 m.