Evidence for short-time connections of the NW margin of tethys and subboreal realm during the late Tithonian and Early Berriasian in the Outer Western Carpathians

0495478 - ÚGN 2019 RIV CZ eng A - Abstract
Svobodová, A. - Reháková, D. - Švábenická, L. - Vašíček, Zdeněk
Evidence for short-time connections of the NW margin of tethys and subboreal realm during the late Tithonian and Early Berriasian in the Outer Western Carpathians.
Folia Musei Rerum Naruralium Bohemiae Occidentalis Geologica et Paleobiologica. Plzeň: Geologický ústav AV ČR, West Bohemian Museum in Pilsen, 2018 - (Pšenička, J.). s. 86-86. ISBN 978-80-7247-145-4. ISSN 1805-2371.
[Czech-Slovak -Polish Palaentological Conference and MIKRO 2018 Workshop /19./. 18.10.2018-19.10.2018, Praha]
Institutional support: RVO:68145535
Keywords : macro- and microfossils * Tithonian and Berriasian * ammonites * Outer Western Carpathians * Silesian Unit
OECD category: Paleontology

Some macro- and microfossils highlight the effects of cold waters in the Outer Western Carpathians, Silesian Unit and Magura Group of Nappes respectively. In Tithonian and Berriasian, this depositional area was situated at the NW margin of Tethys and separated from the south (nowdays Pieniny Klippen Belt and Inner Carpathians) by Silesian Cordillera and Czorsztyn ridge (Golonka et al. 2006). Although the majority of ammonites found in the Silesian Unit is characteristic of the Mediterranean and Black Sea Tethyan area, the occurrence of ammonites represented by genera Riasanites and Riasanella proves the communication with the Subboreal region of the Russian Plarform in early Berriasian (Vašíček et al. 2017). Compared with other sites of Tethys, distinct differences were also recorded in calpionellids, dinoflagellate cysts, and calcareous nannofossils (Svobodová et al. submitted, Švábenická et al. 2018). Cold waters are indicated by rare calpionellids represented mainly by hyaline forms, by the absence of chitinoidellids, and by quantitatively different composition of nannofossil assemblages. This includes 1. quantitative dominance of Watznaueraciae (up to 98%), 2. a smaller percentage of Nannoconus (0.2-5.0 %), Polycostella (0.2-5.0 %) and Conusphaera (0.5-12.0 %), 3. presence of Nannoconus compressus known especially from the Atlantic Ocean (Casellato 2010), 4. scarce “predominantly tethyan taxa” Helenea chiastia, Cruciellipsis cuvillieri, and Speetonia colligata (sensu Bown and Cooper, 1998).
Permanent Link: http://hdl.handle.net/11104/0288451