Anthropogenic-scale CO2 degassing from the Central Atlantic Magmatic Province as a driver of the end-Triassic mass extinction

Manfredo Capriolo,Benjamin J.W Mills,Paul B Wignall,Alexander M Dunhill,Jacopo Dal Corso,Andrea Marzoli,Robert J Newton

doi:10.1016/j.gloplacha.2021.103731

Abstract

The climatic and environmental impact of exclusively volcanic CO2 emissions is assessed during the main effusive phase of the Central Atlantic Magmatic Province (CAMP), which is synchronous with the end-Triassic mass extinction. CAMP volcanism occurred in brief and intense eruptive pulses each producing extensive basaltic lava flows. Here, CAMP volcanic CO2 injections into the surface system are modelled using a biogeochemical box model for the carbon cycle. Our modelling shows that, even if positive feedback phenomena may be invoked to explain the carbon isotope excursions preserved in end-Triassic sedimentary records, intense and pulsed volcanic activity alone may have caused repeated temperature increases and pH drops, up to 5 °C and about 0.2 log units respectively. Hence, rapid and massive volcanic CO2 emissions from CAMP, on a similar scale to current anthropogenic emissions, severely impacted on climate and environment at a global scale, leading to catastrophic biotic consequences.

Highlights

The synchrony in the Phanerozoic geological record between biotic crises and the emplacement of Large Igneous Provinces (LIPs) suggests volcanic degassing as the trigger of mass extinction-scale climatic and environmental disruption (e.g., Courtillot and Renne, 2003; Wignall, 2015; Bond and Grasby, 2017; Black et al, 2021)
We considered only the CO2 from the main volcanic phase of Central Atlantic Magmatic Province (CAMP), which occurred at the beginning of its activity and synchronously with the onset of the main extinction phase (Lindstrom, 2021), in order to assess the potential impact of CAMP volcanism on the end-Triassic climate and environ ment
The main difference between these two models is the maximum atmospheric CO2 concentration achieved after the injection of CAMP volcanic CO2, which reflects the gap between the initial conditions

Summary

Introduction

The synchrony in the Phanerozoic geological record between biotic crises and the emplacement of Large Igneous Provinces (LIPs) suggests volcanic degassing as the trigger of mass extinction-scale climatic and environmental disruption (e.g., Courtillot and Renne, 2003; Wignall, 2015; Bond and Grasby, 2017; Black et al, 2021). The Central Atlantic Magmatic Province (CAMP) is one of the most voluminous known LIPs, emplaced through brief and intense pulses (Marzoli et al, 1999, 2018, 2019; Knight et al, 2004), and coincides in time with the end-Triassic mass extinction (Marzoli et al, 2004; Schoene et al, 2010; Blackburn et al, 2013; Davies et al, 2017). The initial and most severe phase of the biological crisis occurred synchro nously with the main phase of CAMP volcanism (Lindstrom, 2021). This coincidence strengthens the causality relationship between the volcanic activity and the biotic crisis, and highlights the potential impact of this CAMP volcanic phase on the end-Triassic cascade of ecological and biological events

Methods

Results

Conclusion