Wyniki wyszukiwania - BazTech

Ograniczanie wyników

Powiadomienia systemowe

Sesja wygasła!

Znaleziono wyników: 2

Liczba wyników na stronie

Wyniki wyszukiwania

Wyszukiwano:
w słowach kluczowych: Middle Turonian

Sortuj według:

Ogranicz wyniki do:

Middle Turonian trace fossils from the Bystrzyca and Długopole sandstones in the Nysa Kłodzka Graben (Sudetes, SW Poland)

Chrząstek A.

Geological Quarterly

2013

Vol. 57, No. 3

443–-466

The Middle Turonian sediments of the Nysa Kłodzka Graben (Bystrzyca Sandstone in the Stara Bystrzyca outcrop and the Długopole Sandstone in Długopole Górne Quarry) contain trace fossils, which include Curvolithus simplex, ?Macaronichnus isp., Ophiomorpha nodosa, Ophiomorpha isp., Palaeophycus tubularis, Thalassinoides cf. paradoxicus, T. suevicus and Thalassinoides isp. The assemblage of trace fossils points to the proximal Cruziana ichnofacies, that characterizes the distal lower shoreface and the archetypal Cruziana ichnofacies, typical of upper offshore settings. The trace fossils evidence implies that sedimentation took place in a shallow basin with periods of a sudden sediment input, good oxygenation and normal salinity. The Bystrzyca and Długopole sandstones are deposits of the shallow epicontinental sea that were deposited between the fair-weather and storm-wave base, in the distal lower shoreface–upper offshore setting. The Bystrzyca Sandstone is recognized as storm-originated deposits, whereas the Długopole Sandstone is probably the part of prograding “accumulation terrace”. The source of material for the sandstone was the East Sudetic Island and probably also the Orlica–Bystrzyca Uplift. The studied sandstones are related to a regression that started in the early/middle Middle Turonian and caused a relative uplift of the surrounding land.

Palaeontology of the Middle Turonian limestones of the Nysa Kłodzka Graben (Sudetes, SW Poland): biostratigraphical and palaeogeographical implications

Chrząstek Alina

Geologos

2012

Vol. 18, No. 2

83--109

The ammonites Lewesiceras peramplum Mantell and ?Lewesiceras sp. are reported from the Upper Cretaceous in the Nysa Kłodzka Graben; they date from the Middle Turonian and ?Coniacian, respectively. The Middle Turonian limestones of the Stara Bystrzyca quarry contain an abundant assemblage of inoceramids (Inoceramus cuvieri Sowerby and I. lamarcki Parkinson) and other bivalves, including oysters, as well as brachiopods and trace fossils. Micropalaeontological data show the presence of foraminifers and siliceous sponge spiculae, bryozoans, ostracods and fragments of bivalves and gastropods. The Middle Turonian calcareous deposits belongs to the upper part of the Inoceramus lamarcki Zone (late Middle Turonian) and were deposited on a shallow, subtidal offshore shelf. They overlie the Middle Turonian Bystrzyca and Długopole Sandstones, which represent foreshore-shoreface delta deposits. The fossil assemblage suggests a moderate- to low-energy, normal-salinity environment with occasionally an oxygen deficit.