Methane emissions behind one of the most catastrophic Earth’s crises

Direct evidence of abundant methane degassing has been detected in 201 million year-old rocks emplaced during magmatic activity contemporaneous with the end-Triassic mass extinction. This process likely contributed to severe climate change during this time. The study, published this week in Nature Communications, has been carried out by an international research team, including Manfredo Capriolo (lead author) and Sara Callegaro from CEED.

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Process of magmatic intrusion and magma–sediment interaction, followed by fluid release from the Amazonian basins 201 million years ago. Sketch figure from Capriolo et al. (2021).

During the last 500 million years, mass extinctions and global climate changes are synchronous with exceptional magmatic events. But what caused one of the most devastating mass extinctions occurred 201 million years ago? A new study, published in Nature Communications (“Massive methane fluxing from magma–sediment interaction in the end-Triassic Central Atlantic Magmatic Province”) reveals a massive release of methane from the Amazonian basins (Brazil) during the end-Triassic mass extinction. About 1 million cubic kilometers of basaltic magmas intruded and heated organic matter-rich sedimentary rocks, which in turn released massive amounts of methane.

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Micrometer-sized fluid inclusion (indicated by the red arrow) containing a methane bubble (with spherical shape) and a salt crystal (with cubic shape) in a salty aqueous liquid, which preserve the original composition of fluids deriving from magma–sediment interaction, within a quartz crystal in a doleritic rock from the Amazonas Basin (sample from Monte Alegre, State of Pará, Brazil). Credits to Manfredo Capriolo.

In this article, a team of international researchers led by Manfredo Capriolo (University of Padova, Italy, and now at CEED, University of Oslo) detected the presence of methane in microscopic fluid droplets preserved in quartz crystals of magmatic rocks. Methane is a high-impact greenhouse gas, and its involvement in the end-Triassic crisis was already hypothesized and modelled, but this is the first time that methane was directly detected within end-Triassic magmatic rocks. "The analysis of micrometer-sized fluid inclusions entrapped within 201 million years-old magmatic crystals provided the first direct evidence of the release of huge amounts of methane, produced by the heating of organic matter-rich rocks, at the end of the Triassic" Manfredo Capriolo says.

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Outcrop along the Trans-Amazonian Highway of one of the magmatic intrusions in the Amazonas Basin near the village of Medicilândia (State of Pará, Brazil). Credits to Andrea Marzoli.

According to co-author Sara Callegaro (CEED, University of Oslo), "This study represents a step forward in the knowledge of the greenhouse gas emissions from the end-Triassic Large Igneous Province. Similar evidence of methane deriving from the interaction between magma and sedimentary rocks will probably be found also for other magmatic events, similarly related to mass extinctions." Investigating sources, mechanisms and loads of greenhouse gas emissions during large-scale magmatic events responsible for climatic and biotic crises in Earth’s past is the key for understanding the possible effects of the current anthropogenic emissions.

The authors of this study, with the related involved institutions in brackets, are in the order Manfredo Capriolo (University of Padova, Italy, now University of Oslo (CEED), Norway), Andrea Marzoli (University of Padova, Italy), László E. Aradi (Eötvös Loránd University of Budapest, Hungary), Michael R. Ackerson (Smithsonian Institution of Washington, United States), Omar Bartoli (University of Padova, Italy), Sara Callegaro (University of Oslo (CEED), Norway), Jacopo Dal Corso (China University of Geosciences of Wuhan, China), Marcia Ernesto (University of São Paulo, Brazil), Eleonora M. Gouvêa Vasconcellos (Federal University of Paraná, Brazil), Angelo De Min (University of Trieste, Italy), Robert J. Newton (University of Leeds, United Kingdom) and Csaba Szabó (Eötvös Loránd University of Budapest, Hungary).

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View of the Amazon River from the village of Monte Alegre (State of Pará, Brazil). Credits to Andrea Marzoli.

Contact: Manfredo Capriolo. Email: manfredo.capriolo@phd.unipd.it and manfredo.capriolo@geo.uio.no. Instagram: @maples_nfr

Publication detailsCapriolo, M., Marzoli, A., Aradi, L.E. et al. Massive methane fluxing from magma–sediment interaction in the end-Triassic Central Atlantic Magmatic Province. Nat Commun 12, 5534 (2021). https://www.nature.com/articles/s41467-021-25510-w

Related CEED project:
Norwegian Research Council Young Researcher Talent project - MAPLES : https://www.mn.uio.no/geo/english/research/projects/maples/

By Manfredo Capriolo
Published Sep. 21, 2021 1:51 PM - Last modified Sep. 21, 2021 1:55 PM
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The CEED blog covers some behind-the-scenes about our latest research and activities. The contributors are a mix of students and staff from The Centre for Earth Evolution and Dynamics, Dept. of Geosciences, University of Oslo, Norway.