A Bayesian inversion for emissions and export productivity across the end-Cretaceous boundary

Area of Science:

• Paleoclimatology
• Geochemistry
• Earth System Science

Background:

• The end-Cretaceous mass extinction was influenced by the Chicxulub impact and Deccan Traps volcanism.
• Disentangling the environmental impacts of these events is crucial for understanding extinction mechanisms.

Purpose of the Study:

• To quantify carbon dioxide (CO2) and sulfur dioxide (SO2) emissions, export productivity, and remineralization during the 67-65 million years ago period.
• To differentiate the environmental forcings of the Chicxulub impact and Deccan Traps volcanism.

Main Methods:

• Utilized a parallel Markov chain Monte Carlo approach for model inversion.
• Employed the Long-term Ocean-atmosphere-Sediment Carbon cycle Reservoir (LOSCAR) model.
• Integrated observational and proxy data for model validation.

Main Results:

• Decoupled CO2 and SO2 emissions were identified, indicating distinct volcanic and impact-related contributions.
• A two-step decline in export productivity was observed, followed by a prolonged recovery phase.
• No significant volatile impulse directly at the Cretaceous-Paleogene boundary was detected.

Conclusions:

• The study provides a refined understanding of the environmental dynamics during the end-Cretaceous mass extinction.
• The developed inversion methods offer a pathway for efficiently analyzing complex Earth system models.
• Results highlight the complex interplay of volcanic activity and its impact on ocean biogeochemistry.