138 The Cretaceous-Paleogene (K-Pg) Boundary Interval: From Large-Scale Geological Events to Mass Extinction Mechanisms

The Cretaceous-Paleogene boundary interval witnessed extreme geological events: the Chicxulub impact and Deccan Traps volcanism, and a biological catastrophe. New proxy-records, coupled with numerical modelling, unravel the mechanisms driving the environmental change and mass extinction.

Monday, 20 October 2025
1:30 PM - 5:30 PM
HBGCC, 304A

Short- and Long-term carbon cycle and climate responses due to volcanism, impact, and the aftermath of the Cretaceous/Paleogene mass extinction

Paper number: 138-12
Program: Technical Sessions
Time: 4:30 PM – 4:45 PM

Authors

Abstract

We present the monospecific planktonic foraminiferal δ¹³C records spanning the Cretaceous–Paleogene (K/Pg) boundary, integrating them with other δ¹³C and TEX₈₆ data to assess climatic and carbon cycle responses to the Chicxulub impact, the associated mass extinction, and large-scale volcanism. Our analysis reveals that a short-term (<200 kyr) ~2.75‰ decline in bulk δ¹³C following the K/Pg impact is primarily an artifact of biotic turnover, with only ~0.6‰ reflecting disruptions in the global carbon cycle. In contrast, long-term (>200 kyr) carbon cycle changes are attributable to input from Large Igneous Provinces (LIPs), specifically the Deccan Traps (ca. 66.4–65.5 Ma) and the North Atlantic Igneous Province (ca. 60.5–54 Ma). These LIPs caused global δ¹³C increases of ~1‰ and ~2‰, respectively. The onset of Deccan volcanism triggered CO₂-induced warming of ~2°C and sea-level rise of ~35 m at 66.3 Ma. This was followed by a cooling event in the latest Maastrichtian (~66.05 Ma) punctuated by an impact-induced cooling of at least 10°C in the immediate aftermath of the boundary.

Geological Society of America Abstracts with Programs. Vol. 57, No. 6

doi: 10.1130/abs/2025AM-414039

© Copyright 2025 The Geological Society of America (GSA), all rights reserved. Permission is hereby granted to the author(s) of this abstract to reproduce and distribute it freely, for noncommercial purposes. Permission is hereby granted to any individual scientist to download a single copy of this electronic file and reproduce up to 20 paper copies for noncommercial purposes advancing science and education, including classroom use, providing all reproductions include the complete content shown here, including the author information. All other forms of reproduction and/or transmittal are prohibited without written permission from GSA Copyright Permissions.