138-11 Short- and Long-term carbon cycle and climate responses due to volcanism, impact, and the aftermath of the Cretaceous/Paleogene mass extinction

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

Presenting Author:

Kenneth Miller

Authors:

Miller, Kenneth G.¹, Browning, James V.², Vellekoop, Johan³, Esmeray-Senlet, Selen⁴, Schmelz, William J.⁵, Wright, James D.⁶

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 Program. Vol. 57, No. 6, 2025

doi: 10.1130/abs/2025AM-9846

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