Stratigraphy, plankton communities, and magnetic proxies at the Jurassic/Cretaceous boundary in the Pieniny Klippen Belt (Western Carpathians, Slovakia)

0462062 - GLÚ 2017 RIV SK eng J - Journal Article
Michalík, J. - Reháková, D. - Grabowski, J. - Lintnerová, O. - Svobodová, Andrea - Schlögl, J. - Sobien, K. - Schnabl, Petr
Stratigraphy, plankton communities, and magnetic proxies at the Jurassic/Cretaceous boundary in the Pieniny Klippen Belt (Western Carpathians, Slovakia).
Geologica Carpathica. Roč. 67, č. 4 (2016), s. 303-328. ISSN 1335-0552. E-ISSN 1336-8052
R&D Projects: GA ČR(CZ) GA16-09979S
Institutional support: RVO:67985831
Keywords : J/K boundary * pelagic limestones * microfauna * nannoplankton * stable C and O isotopes * magnetic susceptibility * northern Tethys
Subject RIV: DB - Geology ; Mineralogy
Impact factor: 1.358, year: 2016

Upper Tithonian–Lower Berriasian Strapkova sequence of hemipelagic limestones improves our understanding of environmental changes occurring at the Jurassic/Cretaceous (J/K) boundary in the Western Carpathians. Three dinoflagellate and four calpionellid zones have been recognized. The onset of the Alpina Subzone, was used as a marker of the J/K boundary. Calpionellids and calcified radiolarians numerically dominate in microplankton assemblages. The first occurrence of Nannoconus wintereri indicates the beginning of the nannofossil zone NJT 17b Subzone. The FO of Nannoconus steinmannii minor was documented in the lowermost part of the Alpina Subzone. This co-occurrence of calpionellid and nannoplankton events along the J/K boundary transition is typical of other Tethyan sections. Correlation of calcareous microplankton, of stable isotopes (C, O), and TOC/CaCO3 data distribution was used in the characterization of the J/K boundary interval. Δ13C values (from +1.09 to 1.44 ‰ VPDB) do not show any temporal trends and thus show a relatively balanced carbon-cycle regime in sea water across the J/K boundary. The presence of radiolarian laminites, interpreted as contourites, and relatively high levels of bioturbation in the Berriasian prove oxygenation events of bottom waters. The lower part of the Crassicolaria Zone (up to the middle part of the Intermedia Subzone) correlates with the M19r magnetozone. The M19n magnetozone includes not only the upper part of the Crassicollaria Zone and lower part of the Alpina Subzone but also the FO of N. wintereri and N. steinmannii minor. The reverse Brodno magnetosubzone (M19n1r) was identified in the uppermost part of M19n. The top of M18r and M18n magnetozones are located in the upper part of the Alpina Subzone and in the middle part of the Ferasini Subzone, respectively. The Ferasini/Elliptica boundary is located in the lowermost part of the M17r magnetozone. FO of N. steinmannii steinmannii was identified in the M17r magnetozone.
Permanent Link: http://hdl.handle.net/11104/0261604