Bio-evolution patterns in a green-house world: Calcareous nannofossils from the Cenomanian-Turonian interval of NW-Europe
Final Report Abstract
The Cretaceous world was characterized by a greenhouse climate much warmer than today. As a consequence of this greenhouse climate the Cretaceouse was affected by several periods of worldwide oceanic anoxia, the so called Oceanic Anoxic Events (OAEs). The OAE2, one of the most prominent of these events, which occurred during the Late Cenomanian - Early Turonian was probably caused by this extreme warming. Both, the peak warming and the OAE2 affected the marine ecosystem including planktonic primary producers such as calcareous nannofossils. In our original we therefore proposed a palaeoecologic study of the Cenomanian-Turonian transition of calcareous nannofossils from several European sections. The Wunstorf core was the main focus of our study. This section was drilled to recover the complete Cenomanian-Turonian boundary interval. Other European sections (Goban Spur, Eastbourne, Baddeckenstedt, Konrad 101) should supply data to be compared with the results from Wunstorf. These sections form a transect from the inner shelf (Wunstorf, Baddeckenstedt, Konrad 101) across the outer shelf (Eastbourne) to the open ocean (Goban Spur). The preservation of calcareous nannofossils is moderate to good throughout all studied sections. We used the same settling method to process the samples from the three studied sections (Wunstorf, Eastbourne, Goban Spur) in order to gain comparable nannofossil data. A total of 105 samples has been studied with respect to calcareous nannofossils from the Cenomanian-Turonian interval of the Wunstorf core. Additional 84 samples have been examined from the Cenomanian-Turonian transition from Eastbourne and another 35 Cenomanian-Turonian samples from Goban Spur (DSDP Sites 549 and 551). Furthermore we analyzed 42 samples of the Coniacian-Maastrichtian of Goban Spur (DSDP Site 549). In addition to calcareous nannofossil assemblage studies (biostratigraphy, abundance counts) we investigated the biometry of five calcareous nannofossil genera (Biscutum, Broinsonia, Prediscosphaera, Retecapsa, Watznaueria) in 45 samples from Goban Spur. We intended to address the following questions: 1) To understand the influence of Cenomanian-Turonian palaeo-environmental changes on the calcareous nannofossil assemblages of the European shelf. 2) To show potential differences among assemblages from sections with (Wunstorf) and without black shales (Eastbourne). 3) To compare the composition of open oceanic (Goban Spur) and coastal assemblages (Wunstorf). 4) To document the Late Cretaceous size evolution of the four most common placolith genera (Biscutum, Prediscosphaera, Retecapsa, Watznaueria) and the Arkhangelskiellaceae. This project covered the funding for a PhD student for three years (Christian Linnert), salaries for students, travel expenses and consumables. The lab work was done in Bochum in the calcareous nannofossil laboratory (sample preparation, microscopic work, biometry). During the time of funding we also finished a palaeoecologic and biometric study on Campanian-Maastrichtian calcareous nannofossils from Blake Nose.
Publications
-
2009. Biometry of the late Cretaceous Arkhangelskiella group:
ecophenotypes controlled by nutrient flux. Cretaceous Research,
Vol. 30. 2009, Issue 5, pp. 1193–1204.
Linnert, C., Mutterlose, J.
-
2009. Evidence of increasing surface water oligotrophy during the
Campanian-Maastrichtian boundary interval: Calcareous nannofossils from DSDP Hole 390A (Blake Nose). Marine Micropaleontology, Vol. 73. 2009, Issues 1–2, pp. 26–36.
Linnert, C., Mutterlose, J.,
-
2010. Calcareous nannofossils of the Cenomanian/Turonian boundary interval from the Boreal Realm (Wunstorf, northwest Germany).
Marine Micropaleontology, Vol. 74. 2010, Issues 1–2, pp. 38–58.
Linnert, C., Mutterlose, J., Erbacher, J.,
-
2011. Calcareous nannofossils from Eastbourne (southeastern England) and the paleoceanography of the Cenomanian-Turonian boundary interval. Palaios, Vol. 26.2911, Issue 5, pp. 298-313.
Linnert, C., Mutterlose, J., Mortimore, R.
-
2011. Late Cretaceous (Cenomanian– Maastrichtian) calcareous nannofossils from Goban Spur (DSDP Sites 549, 551): Implications for the palaeoceanography of the proto North Atlantic.
Palaeogeography, Palaeoclimatology, Palaeoecology, Vol. 299. 2011, Issues 3–4, pp. 507–528.
Linnert, C., Mutterlose, J., Herrle, J.O.
