Central Atlantic Magmatic Province was GeoChronologically Aligned WIth Triassic Jurassic Mass Extinction

Geochemical consequences of intense pulse-like degassing during the onset of the Central Atlantic Magmatic Province

Authors:

Paris et al

Abstract:

The Triassic–Jurassic boundary (TJB) is marked by one of the five largest mass extinctions of the Phanerozoic and the eruption of a large igneous province: the Central Atlantic Magmatic Province (CAMP). The TJB is characterized by a carbonate production crisis, by negative excursions in the carbon isotopic ratio of buried organic matter, and by successive peaks in atmospheric CO2. Here we use the numerical model GEOCLIM to explore the possible connections between the CAMP emplacement and the observed carbon cycle perturbations. Different degassing scenarios linked to the CAMP eruption are explored. We show that the emission of realistic amounts of CO2 that follow a geologically constrained degassing scenario as short-term peaks (less than 10 ka) leads to successive decrease in carbonate production, as observed in the geological record. We also calculate the evolution of carbon isotopes and show that our model reproduces the amplitude of the isotopic excursion with a volcanic degassing of CO2 characterized by a carbon isotopic composition of − 20‰. Such low values could be associated to carbon pools of light isotopic composition located at the transition zone [Cartigny, P. 2010, Earth and Planetary Science Letters, v. 296, p. 329–339] and not necessarily to biogenic methane release. Finally, the model predicts a succession of short-term CO2 rises, with an amplitude in close agreement with available proxy-based reconstructions.

YAGUMETs! Flood Basalt Eruptions Mass Extinction Impacts are Depend on WHERE the Eruption Takes Place

The effects of large igneous provinces on the global carbon and sulphur cycles

Authors:

Jones et al

Abstract:

The correlation between large igneous provinces (LIPs), extinction events, and rapid climate change suggests that volcanism can have a detrimental impact on Earth surface conditions. Changes in atmospheric and ocean chemistry, particularly the climate-sensitive carbon and sulphur cycles, are among the most probable processes for inducing global environmental stress. However, the interactions and feedbacks between volcanism and these cycles are numerous and complex, making the characterisation of the response to a LIP challenging. Here we summarise the sources and sinks of carbon and sulphur from large scale volcanism and magmatism using information from modern and ancient systems. For the sources, we review the current understanding of volcanic emissions, and explore the relative contributions and importance of magma-derived degassing versus volatile release from sediments affected by igneous intrusions and lava. In addition, we explore the various ways in which LIPs can reduce atmospheric concentrations of these same elements. The relative influences of each source and sink are in part determined by the mode of LIP emplacement and eruption style, along with the subsequent timescales of such effects. We focus on a few key examples, including the Siberian Traps, the Paraná-Etendeka, and the Central Atlantic Magmatic Province (CAMP), to demonstrate how the environmental impact can vary considerably with differing modes of emplacement, LIP duration, and eruption styles. In particular, we show that the host rocks can have a dominant role as a source or sink of emissions, depending on the lithologies affected by the LIP emplacement.

Massive Earthquake(s?) at the Triassic-Jurassic Extinction

Intense and widespread seismicity during the end-Triassic mass extinction due to emplacement of a large igneous province

Authors:

Lindström et al

Abstract:

Multiple levels of earthquake-induced soft-sediment deformations (seismites) are concentrated in the end-Triassic mass extinction interval across Europe. The repetitive nature of the seismites rules out an origin by an extraterrestrial impact. Instead, this intense seismic activity is linked to the formation of the Central Atlantic magmatic province (CAMP). By the earliest Jurassic the seismic activity had ceased, while extrusive volcanism still continued and biotic recovery was on its way. This suggests that magmatic intrusions into sedimentary strata during early stages of CAMP formation caused emission of gases (SO2, halocarbons, polycyclic aromatic hydrocarbons) that may have played a major part in the biotic crisis.

Sulfur Very Important for Volcanicly Driven Mass Extinctions?

Microanalyses link sulfur from large igneous provinces and Mesozoic mass extinctions

Authors:

Callegro et al

Abstract:

Volcanic gases can have devastating impacts on Earth's environment and life. However, measurement of volatile elements in prehistoric magmas is challenging. We present a new method for determining sulfur contents in magmas using its concentrations in clinopyroxenes and an experimentally determined crystal-melt partition coefficient. Using this method we compared magmatic sulfur contents in the Paraná-Etendeka large igneous province (LIP; South America) and two other similarly sized LIPs, the Central Atlantic magmatic province (CAMP) and the Deccan Traps (India). We found that the CAMP and Deccan Traps, both associated with major extinction events, contained high magmatic sulfur concentrations, up to 1900 ppm. Conversely, the Paraná-Etendeka LIP, lacking significant environmental effects, had substantially lower magmatic sulfur concentrations, less than 800 ppm.

They ought to look at the Permian Extinction/Siberian Traps.  I am a bit surprised they did not.  And, again, the Deccan Traps have dinosaur fossils below, between and above the lava flows.

Late Triassic Mass Extinction Shows Common Patterns with the Permian Extinction

Elevated pCO2 leading to Late Triassic extinction, persistent photic zone euxinia, and rising sea levels

Authors:

1. Caroline M.B. Jaraula (a)
2. Kliti Grice (a)
3. Richard J. Twitchett (b)
4. Michael E. Böttcher (c)
5. Pierre LeMetayer (a)
6. Apratim G. Dastidar (a)
7. L. Felipe Opazo (b)

Affiliations:

a. Curtin University, Western Australia Organic and Isotope Geochemistry Centre, Department of Chemistry, Curtin University, Perth, WA 6845, Australia

b. Plymouth University, Geography, Earth and Environmental Sciences, Plymouth PL4 8AA, UK

c. Leibniz Institute for Baltic Sea Research, Geochemistry & Isotope Geochemistry Group, Marine Geology Section, Warnemünde, D-18119 Rostock, Germany

Abstract:

The Late Triassic mass extinction event is the most severe global warming-related crisis to have affected important extant marine groups such as scleractinian corals, and offers potential insights into climate change scenarios. Here we present evidence from Chlorobi-derived biomarkers of episodic and persistent photic zone euxinia. From biomarkers and stable carbon isotopes, we present evidence of rapid mixing of atmospheric and oceanic carbon reservoirs. Global versus regional trends are resolved in kerogen organic matter type, carbonate δ13C, and bulk and pyrite δ34S. This suite of data demonstrates for the first time a comprehensive organic and stable isotope geochemical reconstruction of events leading up to the Late Triassic extinction event and its aftermath. The cascade of events prior to, during, and after the extinction is remarkably similar to those reported for the Late Permian extinction, the largest extinction event of the Phanerozoic. We predict that similar conditions will have occurred during all past episodes of rapid global warming and biotic crisis that are associated with similar rises in pCO2.

CAMP Tied to TJ Extinction Within 30K Years Radiometrically

To incriminate a global catastrophe in the extinction of a wide swath of the biosphere, you need precise dates for two events: the catastrophe—say, an asteroid impact or volcanic eruption—and the mass extinction. At the meeting, geochronologists who measure the passage of time in the steady ticking of radioactive decay presented convincing evidence that massive eruptions at the opening of the Atlantic Ocean 201 million years ago drove the mass extinction that cleared the way for the rise of the dinosaurs.

The dating—by Terrence Blackburn of the Carnegie Institution for Science in Washington, D.C., and colleagues—was impressively precise. For minerals from the end of the Triassic period, 201 million years ago, the researchers reported ages to three decimal places with a 1-sigma error of about 30,000 years, just 0.015% of the ages. That kind of precision takes careful measurements of the amounts of the radioactive element of interest and the product of its decay. That's quite a feat in mineral grains that have been ravaged for hundreds of millions of years by both the environment and their own radioactivity.

[...]

Near the end of the Triassic period, millions of cubic kilometers of magma spewed from the crack that split the supercontinent Pangaea in two and started the opening of the Atlantic Ocean. Debris from the eruptions might have chilled the climate or poisoned the environment, triggering the extinction. But previous dating had had the extinction coming before the first volcanic outburst, not at the same time.

So Blackburn and his colleagues used the latest uranium-lead techniques to date volcanic samples from seven sites on the East coast of North America and one site in Morocco. They dated the end-Triassic extinction to 201.562±0.016 million years ago (subject to change in peer review). Adding in dating of sediments surrounding eruption deposits by using astronomical cycles, they could correlate the Moroccan record to the North American record, placing the extinction at the first of three eruption pulses within the small dating errors. And those errors have gotten so small that no one is disputing that the Atlantic opening megaeruptions somehow did in enough critters to unleash the dinosaurs.