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Survivorship of benthic foraminifera across the Danian Warm World
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  • Thulasi Thena,
  • Dhananjai Kumar Pandey,
  • Raj K. Singh,
  • Nisha Nair,
  • KS Roshni
Thulasi Thena
National Centre for Polar and Ocean Research

Corresponding Author:[email protected]

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Dhananjai Kumar Pandey
National Centre for Polar and Ocean Research
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Raj K. Singh
Indian Institute of Technology, Bhubaneswar
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Nisha Nair
National Centre for Polar and Ocean Research
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KS Roshni
National Centre for Polar and Ocean Research
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Abstract

Three major geological events: The cretaceous-Paleogene (K/Pg) transition, Dan-C2, and the Latest Danian Event (LDE) during the Early Paleocene geologic period caused potential impacts over mass extinctions of several marine life and also rapid change in climate from icehouse to warmhouse condition. The effects of these events on the marine community in the Indian Ocean are not well understood in comparison to other oceans. Here we investigate benthic foraminiferal diversity patterns, morphotypes, and oxygen conditions along with the carbonates and magnetic susceptibility records in the Indian Ocean sediments to understand the Danian Warm World (DWW). Deep-sea sediments from the International Ocean Discovery Program (IODP) Site U1457 (Laxmi basin, Northern Indian Ocean) at ~1100 meters below the seafloor (mbsf) of the Danian period (c. 66 – 61.6 Ma) are examined, which suggest that the foraminifera subsisted across major events. Species belonging to Bolivina, Glandulina, Hoeglundina, Parrelloides and Quadrimorphina genus were dominant above the K/Pg boundary whereas Bolivina, Bulimina, Cassidulina, Cornuspira, Gyroidinoides, Melonis, Oolina, Pullenia, Reussoolina and Rutherfordoides were dominated across the hyperthermal events. We also calculated the average oxygen content at 0.16 ml/L in accordance with oxyphilic species abundance, which serves as supportive evidence, in defining Laxmi basin favours a suboxic to dysoxic environment. The benthic foraminiferal diversity pattern, primary anomalies of calcium carbonates, magnetic susceptibility, and previous global datasets of carbon and oxygen isotopes attempted to mark the period of geologic events at the study site.
30 Mar 2023Submitted to ESS Open Archive
04 Apr 2023Published in ESS Open Archive