Abstract
Abstract. Foraminiferal occurrences in marine sediments of Late Valanginian age (Early Cretaceous) are described from NW Germany. The distribution patterns of benthic foraminifera are discussed with respect to their abundance and diversity. Benthic foraminifera are characterized in terms of moderate diversity and abundance. Vertical fluctuations in foraminifera contents are discussed with respect to their palaeoecology and palaeobiogeography. Benthic foraminifera, which are represented by a total of 101 species, show a gradual increase of diversity throughout the Late Valanginian. This improvement of living conditions in an epicontinental sea over a period of approximately 2 million years indicates a gradual recolonization of the formerly non-marine semi-restricted basin. The associations are dominated by agglutinated taxa with common Ammobaculites, Ammovertella, Bulbobaculites, Haplophragmoides, Proteonina, Psammosphaera and Reophax. The calcareous species Epistomina caracolla, which is extremely common in certain intervals, may reach significant abundances. Further agglutinated and calcareous taxa occur rarely. The early Late Valanginian is marked by the occurrence of the Tethyan species Cerobertinella subhercynica, reflecting a major sea-level highstand.
Highlights
Studies dealing with earliest Cretaceous benthic foraminifera from NW Germany concentrated mainly on stratigraphic and taxonomic aspects (e.g. Bartenstein & Brand, 1951; Bartenstein & Bettenstaedt, 1962)
The distribution pattern of benthic foraminifera of the NW German Basin (NWGB) is controlled by distinctive palaeoenvironmental signals on different scales
The ecological conditions improved only slowly in this epicontinental sea, over a period of approximately 2 million years, indicated by a gradual recolonization of the formerly non-marine semirestricted basin. This is supported by diversity patterns throughout Valanginian and Hauterivian times
Summary
Studies dealing with earliest Cretaceous benthic foraminifera from NW Germany concentrated mainly on stratigraphic and taxonomic aspects (e.g. Bartenstein & Brand, 1951; Bartenstein & Bettenstaedt, 1962). Bartenstein & Brand, 1951; Bartenstein & Bettenstaedt, 1962). Studies dealing with earliest Cretaceous benthic foraminifera from NW Germany concentrated mainly on stratigraphic and taxonomic aspects It is only in the late 1980s and early 1990s that interest in benthic foraminifera of the Valanginian of this area was revitalized by studies of Niedziolka (1988) on stratigraphic aspects and by Meyn & Vespermann (1994) on taxonomic problems. The only study which covers palaeoecological and sequence stratigraphical aspects was published by Stadtler (1998) and concentrates on the Early Valanginian Bentheim Sandstone and its sequence stratigraphic interpretation. During the last fifteen years extensive sampling of Lower Cretaceous sediments from outcrops in northern Germany has been performed
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
