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

作者：Chrzastek Alina^*

来源：Geological Quarterly, 2013, 57(3): 443-466.

DOI：10.7306/gq.1105

• trace fossils
• ichnofacies
• Cretaceous
• palaeoenvironments
• Middle Turonian
• Sudetes

The Middle Turonian sediments of the Nysa Klodzka Graben (Bystrzyca Sandstone in the Stara Bystrzyca outcrop and the Dlugopole Sandstone in Dlugopole Gorne 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 Dtugopole 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 Dlugopole 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.

• 出版日期2013