Aptian boundary interval in NW Germany

Aptian boundary interval in NW Germany

Cretaceous Research (1998) 19, 537±538 Article No. cr980118 The Barremian/Aptian boundary interval in NW Germany Foreword This issue of Cretaceous ...

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Cretaceous Research (1998) 19, 537±538

Article No. cr980118

The Barremian/Aptian boundary interval in NW Germany

Foreword This issue of Cretaceous Research comprises six papers on various geological and palaeontological aspects of the Barremian/Aptian boundary interval in NW Germany. These studies are the German contribution to the APTICORE project, part of the international Global Sedimentary Geology Program (GSGP). The project was initiated at a workshop in Perugia (Italy) in 1992. During this meeting APTICORE was proposed as a worldwide coring programme to study the major global event that resulted in the mid-Cretaceous climatic optimum, the `Cretaceous greenhouse'. It has been suggested that increased rates of ocean-¯oor spreading and intraplate volcanism in the Early Aptian caused the onset of the mid-Cretaceous greenhouse (superplume episode). This would have induced global warming, high humidity and sluggish oceanic circulation, resulting in accelerated carbon cycling and increased availability of nutrients. During the course of the workshop in Perugia it was further proposed to sample the Upper Barremian through Aptian level in order to study the vast worldwide changes in geochemistry, palaeoecology and palaeoceanography that occurred during the Barremian/Aptian boundary interval. In 1991 the German Science Foundation (DFG) established the priority research programme ``Global and Regional Processes of Biogenic Sedimentation'', which ended six years later. This was aimed at estimating the varying control biogenic and geological factors had on sedimentation. Part of the programme was the topic ``Sedimentation in the Cretaceous'', which focused on the origin and stratigraphy of sedimentary sequences and cycles with respect to regional and global palaeoceanography and palaeogeography. In this context, from 1991 to 1996 several PhD theses on palaeontological, geological and geochemical topics pertaining to the project APTICORE were funded by the German Science Foundation. In addition to the analysis of sedimentary bedding rhythms, Cretaceous black shales and aspects of palaeoclimate played an important role within the project. The objective of this special issue is to demonstrate the results of this recent APTICORE research which has aimed to: 0195 ± 6671/98/050537 + 2 $30.00/0

# 1998 Academic Press

538

Foreword

(1) develop a high resolution stratigraphy of the Barremian/Aptian boundary interval, including the early Aptian Fischschiefer; (2) analyse the ¯oral and faunal changes across the boundary interval; (3) resolve the palaeoecology and palaeoceanography of the interval on the basis of the ¯ora and fauna recovered from the deposits; (4) describe the variation in geochemical parameters; (5) use the geochemical data as proxies for productivity and the genesis of the sediments of the boundary interval; (6) decipher the geological factors controlling black shale deposition. The six papers are concerned with the clay mineralogy, organic geochemistry, major and minor element geochemistry, calcareous nannofossils and benthic foraminifera of the boundary interval. I am grateful to the many referees of the manuscripts and to the Editor-inChief, D. J. Batten, for their valuable help and effort in bringing about the successful compilation of this special issue of Cretaceous Research. I am especially indebted to A. Bornemann for drawing some of the ®gures for all of the articles. The vigorous support of the research by the German Research Foundation is gratefully achnowledged by all of the authors. JoÈrg Mutterlose Coordinator, German APTICORE Project