Did the Siberian Traps Begin With an Ooze or a Bang?

The onset of flood volcanism in the north-western part of the Siberian Traps: Explosive volcanism versus effusive lava flows

Authors:

Jerram et al

Abstract:

The Siberian Traps large igneous province was formed during the end-Permian, about 252 Ma ago. Basaltic melt was injected into the organic and salt rich Tunguska sedimentary basin, forming interconnected sill complexes and associated hydrothermal vent complexes. Thick deposits of basaltic tuff and tephra covered the paleosurface before the onset of flood volcanism, commonly taken as direct evidence for the explosive nature of the initial phase of volcanism. The field work in this study revealed that tuffs are virtually absent along a 150 km long transect along the Dyupkun lake and Kureika river, even though tuff is shown on available geological maps. Towards the south and west, the transition between the end-Permian sediments and the flood basalts is either characterized by thin (2–5 m) to no tephra deposits (Khantaika area), hyaloclastites and associated lake-deposited tephra (Kureika area), or massive tephra deposits from local eruptive centers (Severnaya area). The new results can be put into the context of other studies about volcanic tuff horizons in Siberia, and questions the notion of province-scale explosive volcanism in Siberia during the onset of flood volcanism. Moreover, the main thicknesses of explosive tuff deposits, up to 700 m, are located in the central and southern parts of the province where the LIP erupted through thick Cambrian salt and carbonate sequences. Since numerous phreatomagmatic pipes are present in these areas, we suggest a causal relationship between deep magma–sediment interactions, explosive eruptions and the resulting environmental stress that initiated the end-Permian mass extinction.

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.

Permian Extinction Lasted 60k Years (+/-), 2/3s of Siberian Traps Eruption Before, During and then Lasted 500 k Years Into Triassic

High-precision geochronology confirms voluminous magmatism before, during, and after Earth’s most severe extinction

Authors:

Burgess et al

Abstract:

The end-Permian mass extinction was the most severe in the Phanerozoic, extinguishing more than 90% of marine and 75% of terrestrial species in a maximum of 61 ± 48 ky. Because of broad temporal coincidence between the biotic crisis and one of the most voluminous continental volcanic eruptions since the origin of animals, the Siberian Traps large igneous province (LIP), a causal connection has long been suggested. Magmatism is hypothesized to have caused rapid injection of massive amounts of greenhouse gases into the atmosphere, driving climate change and subsequent destabilization of the biosphere. Establishing a causal connection between magmatism and mass extinction is critically dependent on accurately and precisely knowing the relative timing of the two events and the flux of magma. New U/Pb dates on Siberian Traps LIP lava flows, sills, and explosively erupted rocks indicate that (i) about two-thirds of the total lava/pyroclastic volume was erupted over ~300 ky, before and concurrent with the end-Permian mass extinction; (ii) eruption of the balance of lavas continued for at least 500 ky after extinction cessation; and (iii) massive emplacement of sills into the shallow crust began concomitant with the mass extinction and continued for at least 500 ky into the early Triassic. This age model is consistent with Siberian Traps LIP magmatism as a trigger for the end-Permian mass extinction and suggests a role for magmatism in suppression of post-extinction biotic recovery.

Evidence of a Crater Lake in the Siberian Traps in During the Permian Extinction

An integrated carbon isotope record of an end-Permian crater lake above a phreatomagmatic pipe of the Siberian Traps

Authors:

Fristad et al

Abstract:

The largest mass extinction in Earth history occurred at the end-Permian (~ 252 million years ago) and is marked by a global negative carbon isotope excursion and the onset of Siberian Trap volcanism, prompting diverse hypotheses on the link between flood basalt volcanism, carbon cycle perturbations, and mass extinction. Phreatomagmatic pipes associated with Siberian Trap volcanism have been proposed as conduits for the release of 12C-enriched carbon gases from thermogenic and/or magmatic sources to the end-Permian atmosphere. Some of the pipes have preserved crater-lake sediments of volcaniclastic origin. This study examined the preserved evidence for 12C-enriched carbon release into the Western Oktyabrsk crater in east Siberia from the underlying volcanic basin. We find that the 13C/12C ratio of the carbonate cement, organic matter, and long-chain n-alkanes in the lacustrine crater sediments support the hypothesis that 12C-enriched carbon infiltrated the basal crater sediments and lake water immediately after crater formation. The values and trends of δ13CCarb, δ13CTOC, and δ13Cn-alkanes in the crater sediments are consistent with 12C-enriched carbon with isotopic values similar to that of carbon sourced from thermogenic and/or 12C-enriched magmatic sources. This implies that carbon release through the pipes in the Tunguska Basin may explain the source of the global negative carbon isotope perturbations, and their coincidence with Siberian Trap volcanism, at the end-Permian.

Siberian Traps may NOT have Burned Coal

Latest Permian chars may derive from wildfires, not coal combustion

Authors:

Hudspith et al

Abstract:

The Permian-Triassic boundary extinction event was the largest biological crisis of the Phanerozoic. One of the principle triggers for the mass extinction is thought to be greenhouse warming resulting from the release of CH4 from basalt-coal interaction during the extensive Siberian Traps (Russia) eruptions. Observations of organic matter interpreted to be coal combustion products (fly ash) in latest Permian marine sediments have been used to support this hypothesis. However, this interpretation is dependent upon vesicular chars being fly ash (coal combustion derived) and not formed by alternative mechanisms. Here we present reflectance microscopy images of vesicular chars from Russian Permian coals, and chars from modern tundra, peatland, and boreal forest fires, to demonstrate that despite a difference in precursor fuels, wildfires are capable of generating vesicular chars that are morphologically comparable to end-Permian fly ash. These observations, coupled with extensive global evidence of wildfires during this time interval, call into question the contribution of coal combustion to the end-Permian extinction event.

Siberian Traps Geochronology Tied VERY Tightly to Permian Triassic Exinction

Geology is partly detective work, and scientists now have enough evidence to book a suspect in the biggest environmental catastrophe in Earth's history.

Painstaking analysis of rocks from China and Russia prove the culprit is a series of massive volcanic eruptions, which flooded ancient Siberia with thick lava flows just before Earth's worst mass extinction almost 252 million years ago, researchers said here yesterday (Dec. 11) at the annual meeting of the American Geophysical Union. Thanks to new computer models of the eruption's devastating effects, and detailed mapping of rocks deposited around the time of the mass dying, researchers now have their best case ever for pinning the extinction on the enormous lava outpouring.

The eruptions — now called the Siberian Traps — lasted less than 1 million years but left behind Earth's biggest "large igneous province," a pile of lava and other volcanic rocks about 720,000 cubic miles (3 million cubic kilometers) in volume. More than 96 percent of marine creatures and 70 percent of land species perished at the end of the Permian Period, versus 85 percent of life in the later dinosaur-killer extinction. In the Permian, all trilobites died out, along with 97 percent of the gorgeous marine creatures called ammonites. Sharks, fish and reptiles were hard hit.

"We can resolve the timing of the Siberian Traps and show that magmatism did precede the onset of mass extinction," said Seth Burgess, an MIT geochemistry graduate student who presented some of the research here.

link.

Permian Extinction Was Really Two Different Extinctions?

Two pulses of extinction during the Permian–Triassic crisis

Authors:

1. Haijun Song (a,*)
2. Paul B.Wignall (b)
3. Jinnan Tong (a)
4. Hongfu Yin (a)

Affiliations:

a. State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences,Wuhan 430074, China,

b. School of Earth and Environment, University of Leeds, Leeds LS2 9JT, UK.

*. e-mail: haijun.song@yahoo.com.cn.

Abstract:

The Permian–Triassic mass extinction is the most severe biotic crisis identified in Earth history. Over 90% of marine species were eliminated1, 2, causing the destruction of the marine ecosystem structure3. This biotic crisis is generally interpreted as a single extinction event around 252.3 million years ago2, 4, 5, 6, and has been variously attributed to the eruption of the Siberian Traps or possibly a bolide impact7, 8, 9, 10. Here we demonstrate that the marine extinction consisted of two pulses, separated by a 180,000-year recovery phase. We evaluated the range of 537 species representing 17 marine groups in seven Chinese sections from a 450,000-year interval spanning the Permian–Triassic boundary. The first stage of extinction occurred during the latest Permian, and was marked by the extinction of 57% of species, namely all plankton and some benthic groups, including algae, rugose corals, and fusulinids. The second phase occurred in the earliest Triassic, and resulted in the extinction of 71% of the remaining species. This second extinction phase fundamentally altered the marine ecosystem structure that had existed for the previous 200 million years. Because the two pulses showed different extinction selectivity, we conclude that they may have had different environmental causes.

Interesting. A few comments here.  

 Woo for looking at the selectivity of the extinctions!  I'd almost think that I had an impact (ahem, pun.  get it!) with my post from way back when entitled 'Stop Dreaming.'

Its been acknowledged for some time that the Permian Extinction had multiple pulses in the event when things died. Once upon a time, the Guadelupean Extinction was thought to be part of the general end Permian Extinction. 

I'm a bit concerned about their accuracy for timing of the two events: 400k years is really, really close when considering that this happened 250 odd million years ago. Being that accurate seems...difficult at best.

Mass extinctions are complex things.  The kill mechanisms are not simply THE VOLCANO DID IT for the Permian Extinction.  My now old post on the subject neglects a number of other things that have come to light since I wrote it in 2006: RUBISCO temperature limits, halogen releasing salt lakes, UV scorching, etc all had their part...yet the root cause was the Siberian Traps even if the kill mechanisms were varied.

Finally, there is the possibility that the the kitchen sink was the culprit: perhaps a bollide and the traps did the deed or some other event combo.  Douglas Erwin made the suggestion back in the early 1990s.  My bet is more on the previous comment: the root cause was straight forward, but that it enabled multiple kill mechanisms.

Permian Extinction Caused by Explosive Rather Than Flood Basalt Volcanism

In a paper published in the November 2012 issue of the journal Geology, Algeo and colleagues from the China University of Geosciences track patterns of carbon isotope ratios associated with volcanic ash layers preserved in southern China rock layers. In particular, the team looked at two rock successions preserving finely layered marine deposits that record volcanic activity from before the end of the Permian period (252 million years ago) through the early part of the next geologic period, the Triassic. These successions contain layers recording events during the crisis that resulted in the extinction of some 90 percent of marine species on Earth.

"These sections have not been studied in detail geochemically," Algeo said. "Because they are deep-marine deposits, they record a very detailed and complete sequence of events. This is something you generally don't find in terrestrial or shallow-marine rocks."

The evidence, Algeo said, demonstrates a volcanic cause of the end-Permian crisis. Volcanic activity contributed to the environmental degradation that accompanied the main extinction horizon at the end of the Permian.

Some researchers have hypothesized that the biotic crisis and mass extinction were caused by the Siberian Traps, a large flood basalt province that erupted approximately 252 million years ago, coinciding more or less with the mass extinction. "This connection has been inferred on the basis of similarities in age and, thus, is circumstantial," Algeo said.

"We demonstrate for the first time that the Permian-Triassic biotic crisis was probably triggered by enormous explosive volcanic eruptions," Algeo said. "We suspect that the ash layers in the Chinese PTB sections are linked to the Siberian Traps, although more research will be needed to verify this."

At the heart of their analysis, the co-authors identify significant changes in the ratio of carbon isotopes at each ash layer in the Chinese sections. This implies large releases of isotopically light, organically derived carbon dioxide or methane with each eruptive event. "This is consistent with large-scale injection of magma into the organic-rich sediments of the West Siberian coal province," Algeo said.

According to Algeo, the Chinese deposits have to potential to clarify the mechanisms that almost wiped out all life on Earth 252 million years ago, and to help in better constraining the timing of the Siberian Traps eruptions.

In earlier research at a variety of locations around the globe, Algeo had compiled evidence that the Permian-Triassic extinction, unlike the more famous Cretaceous-Tertiary extinction in which the large dinosaurs went extinct, was a gradual process. The final extinction event may have been preceded by hundreds of thousands of years of environmental stress. The China research supports this hypothesis of gradual steps toward a dramatic extinction event. The accumulating evidence, he said, points to a very different mechanism, and a far more devastating result, than the end-Cretaceous bolide impact.

"It's becoming clear that almost every mass extinction has a different cause," Algeo said.

Link to the paper. I'm reading. While I am THRILLED that the researcher has rejected YAGUMETs, I am cautious about declaring that this EXPLAINS EVERYTHING.  Its a data point.  A strong one.  However, its not one that necessary explains everything.  Let's see how it fits into the larger picture.  With all due respect to Dr Algeo, the PT Event explanations better than coincidence that environmental degradation was the problem.

Even Nastier Siberian Traps

Around 250 million years ago, at the end of the Permian geologic period, there was a mass extinction so severe that it remains the most traumatic known species die-off in Earth's history. Although the cause of this event is a mystery, it has been speculated that the eruption of a large swath of volcanic rock in Russia called the Siberian Traps was a trigger for the extinction. New research from Carnegie's Linda Elkins-Tanton and her co-authors offers insight into how this volcanism could have contributed to drastic deterioration in the global environment of the period. Their work is published January 9 in Earth and Planetary Science Letters.

The end-Permian mass extinction saw the sudden loss of more than 90 percent of marine species and more than 70 percent of terrestrial species. The fossil record suggests that ecological diversity did not fully recover until several million years after the main pulse of the extinction. This suggests that environmental conditions remained inhospitable for an extended period of time.

Volcanic activity in the Siberian Traps has been proposed as one of the mechanisms that may have triggered the mass extinction. Gases released as a result of Siberian magmatism could have caused environmental damage. For example, perhaps sulfur particles in the atmosphere reflected the sun's heat back into space, cooling the planet; or maybe chlorine and other chemically similar nonmetal elements called halogens significantly damaged the ozone layer in the stratosphere.

The team designed experiments to examine these possibilities.

Led by Benjamin Black of the Massachusetts Institute of Technology, the group included Elkins-Tanton, formerly of MIT and now director of Carnegie's Department of Terrestrial Magnetism, Michael C. Rowe of Washington State University, and Ingrid Ukstins Peate of the University of Iowa.

The geology of the Siberian Traps is comprised of flood basalts, which form when giant lava eruptions coat large swaths of land or ocean floor with basaltic lava. This lava hardens into rock formations. The team investigated concentrations of sulfur, chlorine and fluorine (another halogen) that were dissolved in tiny samples of ancient magma found within basalt samples from the Siberian Traps. These small frozen droplets, which preserve a record of volcanic gases from the time of the eruption 250 million years ago, are called melt inclusions.

Sulfur, chlorine, and fluorine gasses could have been released into the atmosphere from eruptions spewing out of large fissures, which is common in basalt flood formation. Plumes escaping from these cracks could have reached the stratosphere. If sulfur, chlorine, and fluorine made it to the upper atmosphere, these gasses could have cause a wide array of adverse climate events, including temperature change and acid rain.

Based on their findings, the team estimated that between 6,300 and 7,800 gigatonnes of sulfur, between 3,400 and 8,700 gigatonnes of chlorine, and between 7,100 and 13,700 gigatonnes of fluorine were released from magma in the Siberian Traps during the end of the Permian period.

Anyone have the paper itself? I've not been able to find it on the server.

Hmmm: Svenson on Permian Extinction

An ancient killer is hiding in the remote forests of Siberia. Walled off from western eyes during the Soviet era and forgotten among the endless expanse of wilderness, scientists are starting to uncover the remnants of a supervolcano that rained Hell on Earth 250 million years ago and killed 90 percent of all life.

Researchers have known about the volcano -- the Siberian Traps, for years. And they've speculated that the volcanic rocks, which cover an area about the size of Alaska, played a role in runaway global warming that led to the end -- Permian mass extinction, the worst dying the planet has ever seen.

Now a team of researchers led by Henrik Svenson of the University of Oslo in Norway have performed a series of experiments, showing the volcano employed an arsenal of deadly weapons during its 200,000-year-long assault on the biosphere.

Prime among them was carbon. Searing magmas from the volcano intruded into the Tunguska Basin in eastern Siberia, a region laden with thick deposits of coal, oil and gas. Heat from the molten rock baked the hydrocarbons, turning the area into the world's largest fossil fuel-burning plant. In all, the volcano may have belched as much as 100,000 gigatons of carbon into the air (all of humanity emits about eight gigatons of carbon annually).

That's more than enough to cause a global climate apocalypse. But the team also wanted to know what happened when lava infiltrated the area's abundant salt deposits. When heated in a laboratory to 275 degrees Centigrade (527 degrees Fahrenheit), the salts released a host of toxic gases, chief among them methyl chloride, an efficient ozone-killer.

"This is the first geologically realistic evidence that ozone collapse during the end-Permian could have actually happened," Svenson said.

Does anyone have either contact info or the paper that this above article is referencing? I tried looking around on the Unviersity of Oslo website, but can't seem to find Dr Svenson...All I can find is the Discovery article and blog links back to it.