Geological Society of America

T104 Impacts of Volcanism on Global Climate and Oceans—Drivers of Mass Extinctions through the Phanerozoic II

Monday, 11 October 2021
1:30 PM - 5:30 PM
Portland Ballroom 255 (Hybrid Room)

THE ROLE OF DECCAN VOLCANISM ON FAUNAL AND ENVIRONMENTAL CHANGES ACROSS THE CRETACEOUS-PALEOGENE (K-PG) BOUNDARY: EXAMPLES FROM NEO-TETHYS, TURKEY

Paper number: T104-4
Program: Technical Sessions
Time: 2:10 PM – 2:25 PM

Authors

Uygar Karabeyoglu Presenting Author
University of Lausanne, Lausanne
Thierry Adatte
University of Lausanne, Lausanne
Valentin Lorenzo
University of Lausanne, Lausanne
Jorge Spangenberg
University of Lausanne, Lausanne, N/A
Sevinc Ozkan-Altiner
Middle East Technical University, Ankara
Demir Altiner
Middle East Technical University, Ankara

Abstract

Long-lasting multi-disciplinary efforts deliver a correlation between continental flood basalt volcanism and major environmental catastrophes linked with four out of five largest Phanerozoic mass extinctions. Among them the end-Cretaceous mass extinction rests on a unique standing by having coincidence between the Chicxulub impact and the Deccan volcanism. The role of the Deccan volcanism is crucial in order to decipher the interplay between volcanism and the environmental stress. Here were show this interaction by performing high-resolution biostratigraphy, quantitative analysis on species level, coupled with geochemical measurements on two complete section in Mudurnu-Göynük and Haymana basins, Central, Anatolia, Turkey.

Detailed quantitative study on planktonic foraminifera of the Haymana Basin reveals that planktonic foraminiferal community in the latest Maastrichtian is dominated by ecological generalists with small, simple morphologies. Quantitative analysis also shows a systematic reduction in the species richness.

The K/Pg boundary in all sections is characterized by 2-3 mm thick reddish oxidized layer corresponding sudden annihilation of large, ornamented ecological specialists. The boundary also corresponds to enrichment in some critical elements, such as Ir, Te, Hg, Ba, Ni, Cr, Co. Importantly among them, measurements on Maastrichtian and Danian samples show a significant correlation between Hg and Te (R²=0.77). Right after the boundary, there is an acme of Thoracosphaera, and a surge of Guembelitria cretacea indicating ecosystem collapse for post-K/Pg environment. The same levels correspond to sudden enrichment in fecal pellets.

Overall, our multiproxy approach including quantitative biostratigraphy and geochemical analyses highlights the influence of the Deccan volcanism by releasing high amounts of atmospheric CO₂ and SO₂, leading to the climatic changes and associated biotic stress predisposing faunas to eventual extinction at the K/Pg boundary.

Geological Society of America Abstracts with Programs. Vol. 53, No. 6

doi: 10.1130/abs/2021AM-367554

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