Cenomanian and turonian planktonic foraminifera from northwestern and southern germany
Palaeontographica, B Paläophytologie 178(1-3): 7-50
ISSN/ISBN: 0375-0299 Accession: 004897448
Selected Cenomanian and Turonian successions in the mid-Cretaceous of northwest and southern Germany and southeastern France (Heligoland, Baddeckenstedt, Wunstorf; Bad Abbach; Les Lattes) were biostratigraphically and biogeographically studied and correlated by planktonic foraminifers. For the middle Cretaceous of northwest Germany the following datum planes have biostratigraphical importance: the 1st appearance of Rotalipora aff. reicheli at the Lower-Middle Cenomanian boundary succession of the Heligoland and Wunstorf (R. reicheli zone); the 1st appearance of R. cushmani at the upper part of Middle Cenomanian of Wunstorf (R. cushmani zone); the 1st appearance of R. greenhornensis at the Middle-Upper Cenomanian boundary of Wunstorf (R. cushmani-R. greenhornensis zone); the extinction of rotaliporids at the end of Cenomanian and followed by the entry in flood abundance of unkeeled planktonic foraminifers (Zone of grandes globogerines) accompanied by twin-keeled Praeglobotruncanids in the Lower Turonian of Wunstorf and Baddeckenstedt; and the 1st appearance of Marginotruncana aff. schneegansi in the upper Lower Turonian of Wunstorf and Baddeckenstedt. The Cenodomanian-Turonian boundary based on planktonic foraminifers lies in Baddeckenstedt within the base of the Rotplaner and in Wunstorf within the base of the Schwarz-weisse Wechselfolge; it related and as a result synchronous biostratigraphical datum planes can be recognized. The diversity and the zonation of the Upper Cenomanian are identical both in the southern and northern successions. The planktonic foraminiferal associations in the Lower Turonian are more influenced by regional factors. The taxonomy of some planktonic foraminifers and their morphological characters are briefly discussed.