Cenomanian–Coniacian Upper Cretaceous foraminiferal fauna of Lithuania

Foraminiferal assemblages form a unique fauna succession from the Cenomanian to Maastrichtian stages in Lithuania; the Cenomanian-Coniacian succession is discussed in this paper. The first Cretaceous planktonic foraminifera species appeared in the Early Cenomanian. The Cenomanian planktonic foramini...

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Bibliographic Details
Published in:Geologija
Main Author: Venckutė-Aleksienė, Agnė
Format: Article in Journal/Newspaper
Language:Lithuanian
English
Published: 2010
Subjects:
Online Access:http://lmavb.lvb.lt/LMAVB:ELABAPDB5911242&prefLang=en_US
Description
Summary:Foraminiferal assemblages form a unique fauna succession from the Cenomanian to Maastrichtian stages in Lithuania; the Cenomanian-Coniacian succession is discussed in this paper. The first Cretaceous planktonic foraminifera species appeared in the Early Cenomanian. The Cenomanian planktonic foraminiferal association consists of the relatively abundant genus Hedbergella. However, Cenomanian planktonic foraminifera are rare compared to benthic; the latter are numerous, and their assemblage contains various calcareous and agglutinated species. As a result of environmental changes, foraminiferal assemblages gradually changed as well. The newly formed deep-water niches in the Turonian allowed spreading the keeled forms of planktonic foraminifera. Taxonomically, Turonian-Coniacian foraminiferal assemblages are mainly composed of species of the following genera: Praeglobotruncana, Helvetoglobotruncana, Dicarinella, Marginotruncana.