Calcareous nannofossil during the Paleocene Eocene Thermal Maximum in sediments of Walvish Ridge

Compositions and abundances of calcareous nannofossil taxa have been determined in a ca 170 kyrs long time interval across the Paleocene/Eocene boundary at 1-cm to 10-cm resolution from two ODP Sites (1262, 1263) drilled along the flank of the Walvis Ridge in the South Atlantic. The results are comp...

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Bibliographic Details
Main Authors: Raffi, Isabella, Backman, Jan, Zachos, James C, Sluijs, Appy
Format: Other/Unknown Material
Language:English
Published: PANGAEA 2009
Subjects:
208-1262A
208-1262B
208-1263C
208-1263D
DRILL
Drilling/drill rig
Joides Resolution
Leg208
Ocean Drilling Program
ODP
Walvis Ridge
Southeast Atlantic Ocean
Weddell Sea
Online Access:https://doi.pangaea.de/10.1594/PANGAEA.774062
https://doi.org/10.1594/PANGAEA.774062
Description
Summary:Compositions and abundances of calcareous nannofossil taxa have been determined in a ca 170 kyrs long time interval across the Paleocene/Eocene boundary at 1-cm to 10-cm resolution from two ODP Sites (1262, 1263) drilled along the flank of the Walvis Ridge in the South Atlantic. The results are compared to published data from ODP Site 690 in the Weddell Sea. The assemblages underwent rapid evolution over a 74 kyrs period, indicating stressed, unstable and/or extreme photic zone environments during the PETM hyperthermal. This rapid evolution, which created 5 distinct stratigraphic horizons, is consistent with the restricted brief occurrences of malformed and/or weakly calcified morphotypes. The production of these aberrant morphotypes is possibly caused by major global scale changes in carbon cycling in the ocean-atmosphere system, affecting also photic zone environments. No marked paleoecologically induced changes are observed in abundances of the genera Discoaster, Fasciculithus and Sphenolithus at the Walvis Ridge sites. Surprisingly, there is no significant correlation in abundance between these three genera, presumed to have had a similar paleoecological preference for warm and oligotrophic conditions.

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