Calcareous nannoplankton response to middle-late Eocene climate and sea-level changes in the SW Neo-Tethys

Publikation: Bidrag til tidsskriftTidsskriftartikelForskningfagfællebedømt

We investigate the response of calcareous nannoplankton to the middle-late Eocene transition in the SW Neo-Tethys and compare our data to published results from X-ray diffraction (XRD) analysis, element content from X-ray fluorescence (XRF) and the abundance of microfossils in the coarse fractions of the sediment. The nannofossil assemblage is mainly composed of Reticulofenestra spp. (avg. 44%), Sphenolithus spp. (avg. 20%), Discoaster spp. (avg. 18%) and Pontosphaera spp. (avg. 10%). The Relative abundance of Zygrhablithus bijugatus and the Chiasmolithus ratio are used with the visual assessment to evaluate the preservation. The Sphenolithus-Reticulofenestra turnover occurred before the MECO at the Lutetian-Bartonian boundary. Besides the significant influence of an evolutionary gradient caused by the disappearance of numerous species of Sphenoliths, Discoasterids, and Coccolithaceae, and the first appearance of multiple species of reticulofenestrids, paleoenvironmental conditions imposed a significant impact on the calcareous nannofossil assemblages. The abundance of ostracods and the planktic/benthic foraminifera ratio depict relative sea-level changes. The microfossil assemblages and the lithological composition of the sediments track paleoclimatic and paleoenvironmental changes across the Lutetian to Priabonian. Dry conditions marked the middle Lutetian, followed by increased variability in hydrolyzing conditions during the late Lutetian and early Bartonian. An eutrophic and restricted ecosystem with high fine-grained material input is suggested for the Priabonian.

OriginalsprogEngelsk
Artikelnummer102329
TidsskriftMarine Micropaleontology
Vol/bind187
Antal sider15
ISSN0377-8398
DOI
StatusUdgivet - 2024

Bibliografisk note

Funding Information:
My warmest thanks are to Dr. Xavier Crosta, Dr. Ric Jordan nd the anonymous Reviewer for their constructive suggestions that improved the original manuscript. Funding for this study was ensured through internal funds from the University of Copenhagen allocated to J.H.M. Supplementary data can be found online at https://doi.org/10.1594/PANGAEA.932448 .

Publisher Copyright:
© 2023

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