End-Permian Extinction Due to Contact Metamorphism?

David Middleton

Here’s a novel take on the Siberian Traps and the End-Permian extinction:

Geology

Massive underground magma pulse caused the world’s largest mass-extinction

The end-Permian wiped out almost all marine species

Geologists have suggested that Earth’s most severe mass-extinction was caused by a huge pulse of magma which released deadly levels of greenhouse gases into the atmosphere.

In a Nature Communications paper entitled “Initial Pulse of Siberian Traps Sills as the Trigger of the End-Permian Mass Extinction,” the team suggests that a huge magma pulse wiped out 95 per cent of marine species and 70 per cent of land species 252 million years ago.

The end of the Permian period coincided with an abrupt change from dominantly flood lavas to sill intrusions, a type of intrusive igneous rock (rock that has solidified from lava or magma).

In a region known as the “Siberian Traps”, a huge pulse of magma rose up through the Earth, and instead of erupting on the surface, it spread throughout the Earth’s crust, creating a vast network of rock stretching across almost one million square miles.

The magma then solidified between older layers of sedimentary rock into geological formations known as ‘sills’.

Extreme heat from these sills led to ‘contact metamorphism’ (alteration of the composition or structure of a rock by heat or pressure) of carbon-rich rocks.

This released dangerous levels of carbon dioxide, methane and sulphur dioxide into the environment and triggered the end of the Permian period.

[…]

Rest of story here:Wired

Interesting hypothesis.

Unfortunately the Wired article concludes with a totally idiotic paragraph:

This paper gives an insight into millennia-old conditions which have impacted our environment today. During the end-Permian, the biosphere couldn’t protect itself against the sudden, large emission of greenhouse gases, leading to a continual elevation in sea surface temperature across the globe.

And a prominent link to a dreadfully idiotic article:

Whatever caused the End-Permian extinction, it was a really bad thing or bad series of things.  For anyone who thinks that “Earth has entered a sixth mass extinction event,” please read this article: Earth Is Not in the Midst of a Sixth Mass Extinction.

Geology Info:

Traps refer to trap rock.  Trap rock is any fine grained non-granitic igneous rock.   Basalt, peridotite, diabase, and gabbro are types of trap rock.  The Siberian Traps and Deccan Traps were the result of flood basalt events, massive basaltic eruptions.

Sills are shallow igneous intrusions which are generally conformable with sedimentary bedding planes.   Dikes are intrusions which are not conformable.  Basalt and diabase are respectively the extrusive and shallow intrusive versions rocks formed from basaltic magmas.

The Hudson River (AKA New Jersey) Palisades is a diabase sill:

Contact metamorphism is what happens when a hot magma body comes into contact with much cooler rocks near the Earth’s surface.

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125 thoughts on “End-Permian Extinction Due to Contact Metamorphism?

  1. At least geologists are aware that geological science is not settled.
    A seminar of 50 geologists on mineral ore formation will still produce nearly 50 explanations of favoured mechanisms.
    Despite this lack of consensus, good progress is made each day on better understanding the science of geology. Or because of the lack of consensus?
    Geoff. Geochemist, retired.

    • As greenhouse gases are actually a myth and more such gases would serve to cool the planet as “radiative gases,” and the massive amounts of sulfur and ash that undoubtedly accompanied all this sill formation, the planet was under a double assault. [CO2 and water vapor today are zero net effect during the day, but they cool the atmosphere at night, converting heat into IR that is lost to space.]

      The ash and sulfur would cool the atmosphere, blocking incoming solar energy for many years. AND, the sulfur would dissolve in the oceans and truly cause acidification, particularly of the upper oceanic layers where all the life is. Colder water and acidic pH would be a serious killer.

      What the report above does not emphasize is that the wide-ranging sill formation was not without surface events, as sills are offshoots of the main eruptions, and the volcanic emissions would be ongoing and huge.

      • [CO2 and water vapor today are zero net effect during the day, but they cool the atmosphere at night, converting heat into IR that is lost to space.]

        Which is why it gets so damn cold in Jamaica at night and the Sahara desert remains very comfortable at night.

      • The Original Mike M, I think you have it backwards. Water vapor, when it forms clouds, reflects sunlight and cools surface temperatures during the day but serves to retain heat at night. Also, dry deserts cool quicker at night than humid areas:

        “Because of the lack of humidity in the area, the ground receives more than twice the radiation heat from the sun during the day and loses twice as much heat during the night in comparison to more humid environments.”

      • Louis – clouds do not cool the surface. They block sunlight from striking and warming the surface.

      • Louis: Sorry! I forgot the /sarc tag!

        I was pointing out that >>[CO2 and water vapor today are zero net effect during the day, but they cool the atmosphere at night, converting heat into IR that is lost to space.]<< .. is ridiculous.

        At night WV helps retain heat from escaping to space.

    • It’s the lack of consensus that really helps. My preferred Permian hypothesis is that a low carbon atmosphere coupled with an a glacial epoch triggered a collapse of primary production. The loss of carbon during the Paleozoic is well documented. There is strong evidence for a glacial epoch at the Permian Triassic boundary. There is also evidence of decreasing marine oxygen in the terminal Permian suggesting a serious reduction of primary production.

      There is no unequivocal support for a carbon pulse at the end of the Permian. Instead, the CO2 released may account for the apparent rapid recovery during the early Triassic.

      • Personally, I think it was a massive impact. Shattered the crust in the vicinity of the Traps and caused the extinctions both directly and then indirectly via extended volcanism. Much like Shiva crater and the Deccan Traps only worse.

    • I am going to agree with you, Geoff, about geology not being settled. I am an engineer doing some research on my own on a subject that includes a LOT of geology. I have probably read part or all of ~250 papers in the last year or so, with about half of those being on geology. I have seen a lot of competing ideas, and a whole lot of ambiguous evidence that no one has been able to figure out yet.

      Hahaha about the 50 explanations if you gather 50 geologists together. I agree. I’ve been trying to figure out how that can be, but I have to admit that in engineering there is a running joke that if you give 100 engineers the same project to design, you will get AT LEAST 50 designs presented.

      I know WHY it happens in engineering. It is because of the order that the relevent information is absorbed. No two people see a collection of information and SEE it in the same way. For each of them, his eyes and attention are drawn to some information first, and his design ideas begin with those first. Others will focus on others first and their deign will reflect that. Add to that basic idea that each also WEIGHS the information bits differently. Add to those ideas that each engineer’s history leans him in certain directions.

      I seem to have found these qualities also in science papers – which I choose to also apply to the scientists behind the papers. One scientist who gets himself on TV and in videos a good deal has a hypothesis about Libyan Desert Glass and how it came to form. He is absolutely certain he’s found the answer. But the world of physicists and astronomers aren’t lining up behind him. Why not? Could it be because there are at least 5 competing groups of researchers who have come up with 5 OTHER explanations?

      Thomas Kuhn in his articles – from which came the modern idea of paradigms – pointed out that in any science there is a period of chaos, where many concepts and explanations are proposed but none explain everything or are just tentative explanations. (He used the first century or so of the study of electricity as a great example – because they had a helluva time connecting the dots.) Paradigms, Kuhn said, exist only when ONE of the concepts precipitates out of the milieu and comes to dominate. Paradigm shifts come about when some overlooked or underappreciated evidence is taken by some gadfly-slash-reveolutionary and wins the day with a more comprehensive hypothesis.

      While geology puts on a good public face, asserting quite a few KNOWNS, a peek under the rug shows that those knowns are not as ‘known” as we might believe. Especially if what we read is science written for public consumption. VERY FEW of those science editor articles I’ve read in regards to aspects of my project are worth a crap. Most have misleading headlines, asserting things that are not supported by what is actually admitted to in the article by the scientists interviewed for the articles.

      I don’t badmouth the geologists here, actually, though. Finding out things deep in the Earth is NOT easy. They have to be clever enough to find ways to probe deep.

      At the same time, they make a LOT of assumptions and then run with them. That makes me cringe. Assumptions have ways of not being exactly correct.

      – – –
      One magical and relatively new tool is something called magnetotellurics, with which they are presently using electrical evidence to map the depth of the Lithosphere Asthenosphere Boundary (LAB) in several large regions of the world. This will greatly increase their total knowledge about the inside of the planet. If interested, check it out.

  2. I would like to see the model that was used to come up with this piece of garbage science. My take on this is that where there are sills, there are massive explosive strato-injecting volcanic events happening as well. Indeed, the Columbia Basalts also display sills in addition to dike swarms. If these events are relatively continuous, they can lead to massive amounts of solar irradiance reflected back out to space over a long period of time, sometimes with pulses, sometimes continuously. Further, if sulfuric acid ends up in the stratospheric layer, it can stay there for quite some time, harming plant life that is dependent on solar irradiance. All of this is to say that mass starvation from lack of adaquate plant life is a very real risk. CO2 and methane need not apply.

      • Pamela, Taph used the word “tend” which is absolutely correct. Also, your article is not describing explosive volcanic events, but instead high temperature fountains that heat air to very high temperatures over these wide floods, creating large updrafts that carry material aloft with them. Also, they are discussing Deccan Traps in India which formed around the end of the Cretaceous and have been argued as a causal agent in the KT extinction. So, their reasoning is about as trustworthy as the OP. It is based on the same kinds of evidence.

      • No. It models periods of explosive ash producing activity during flood basalt events over a decade or longer that results in lower stratospheric loading. Volcanic events have convective plumes, regardless of type. Sulfuric Acid continues upwards as a plume and has been modeled to be sufficient to enter the stratosphere. Notice the comparison to Laki.

        “The resulting model estimates for
        the convective plumes rising above these fountains,
        based on Woods’ [35,36] treatment of the rise of basaltic
        eruption plumes into a moist atmosphere, indicate eruption
        column heights in excess of 13 km and are similar to
        those estimated for the Laki eruption.”

      • Pamela, we are likely just talking past each other on the meaning of “explosive” when it comes to volcanoes. Your quotation makes the same point I was trying to. The plumes over basaltic eruptions are in general “convective plumes” as what you quoted says. Laki had a terrific plume, but it was not “explosive” in volcanic terms, or not at least when I was studying geology. Thera exploded, as did Krakatoa, Mt St Helens, and Mt. Tehama and many others. Explosive volcanic events are typical of rhyolitic (acidic magma) volcanoes like Stromboli. The biggest explosions that are not tied to “supervolcanoes,” like Yellowstone or Long Valley, are from stratovolcanoes like the volcanoes of the Cascade Range, the Indonesian archipelago, or any island arc system. IIRC, you mentioned living in the Pacific Northwest so you have the best of the North American flood basalts in the Plateau, probably from the continent riding over the Yellowstone plume, and classic subduction-driven example in the Cascade Volcanoes. The basalts have their mysteries. I was in Oregon a few years back collecting obsidian samples from around Riley and many of those obsidian sources are surrounded by basalt.

    • Spot on PG. “…huge pulse of magma which released deadly levels of greenhouse gases into the atmosphere.”

      I tend to think that large amounts of sulphur dioxide released into the atmosphere is far more serious than H2O, CO2, methane or other common volcanic gasses such as flourine and chlorine. If sulphur dioxide is a “greehouse gas” then the study has some value.

      If the hypothesis is correct, and sulphur dioxide was the main gas component, which it is in many basaltic eruptions, then there should be a lot of early Triassic sulphur-rich sediments around the world as the gas is eventually stripped out of the atmosphere. These could be pyritic marine sediments or terrestrial and marine evaporites containing the sulphur minerals gypsum and anhydrite.

      • Their theory seems to be that the Siberian Traps sills intruded hydrocarbon rich sedimentary beds and cooked the carbonates and hydrocarbons, releasing Mega doses of CO2 through diatreme activity. Dubious, in my mind.

  3. Interesting I suppose. Three of the great extinction events of the last 500 million years are associated with flood basalts. The P-Tr with the Siberian traps, the Tr-J with the Newark volcanics found from Georgia to Newfoundland, and the K-T with the Deccan traps. A few years ago, someone found the Iridium layer(s) from the Chicxulub object impact in the middle of the Deccan volcanic sequence. It’s not entirely clear which triggered the mass extinction. Perhaps it was both.

    OTOH, there are plenty of flood basalt events that seem to have had little or no affect on life. And the lakebed deposits between the basalt layers in the Newark rocks yield a lot of fish and plant fossils that don’t seem consistent with life as we know it being erased.

    Anyway, color me skeptical. But I’m willing to change my mind if a raft of supporting evidence turns up. I’m sure there will be plenty of folks out there looking.

    Thanks for posting this

    • It has always seemed to me that, since almost all volcanic eruptions are accompanied by large releases of sulfur and sulfuric compounds, that any mass intrusion of magma onto the surface would be accompanied by the same. Here they are hypothesizing “hmm, must have been excess CO2 that killed those critters” and they’re not even pausing to think about what would happen to a world saturated with H2S, SO2, and H2SO4.

      • Not in the Traps per se, but in the middle of the sequence. There’s also a hypothesis that the Chicxulub impact triggered the Deccan Traps, since they’re almost on the antipods, but nobody’s sure.

      • Don’t remember the details (don’t much care actually). But Gerta Keller’s team seem to have found an Iridium layer in the trap interbads. See http://askwhy.co.uk/dinosauroids/?p=11366 Of course, now that I think about it. Keller’s Iridium layer (assuming that it exists) doesn’t have to be from the Chicxulub object. I wouldn’t be surprised that if one looks long enough and hard enough in enough places for an Iridium enriched layer, one will eventually find one. Meteorites aren’t all that rare and a lot of them explode into a multitude of fragments upon encountering our atmosphere.

    • The more compelling link to the Deccan Traps is the Shiva crater (if such it is). It would implicate an impact several times the size of Chicxulub. It has it’s detractors but it really needs more investigation.

  4. I’m always puzzled by researchers who feel it necessary to add statements to their findings that tie into the man made climate change hoax. Where are the scientific standards once practiced?

    • Actually I think all poisonous gases are also greenhouse gases, but far from all greenhouse gases are poisonous.

  5. The appendage of “greenhouse gases” or “catastrophic climate change” is a secular tic at the end of many papers, much like “amen” in a more religious age.

  6. David

    You are a treasure, between you and Willis the learning never stops! Thank you for your insights.

  7. The full paper is available…

    https://www.nature.com/articles/s41467-017-00083-9

    It doesn’t seem to be plagued with the same alarmist nonsense as the Wired article. Although it does jump to the “blame GHG’s” conclusion after presenting a decent argument for the massive sill emplacement being more closely associated with the Permian extinction than the flood basalt phase.

  8. That is an odd explanation. The conventional Permian extinction interpretation is a double whammy. First a cooling and massive ocean acidification from SO2 released by the Siberian trap flood basalts. The evidence for this is in the sulfur chemistry of sea floor sediments dating to the event. Then a warming caused by CO2 release as the flood basalt ignited massive Siberian coal seam fires. The evidence for this is soot and ‘fly ash’ in Chinese lake sediments dating to the event. Contact metamorphism would have been quite secondary to the Siberian coal.

    • This just piles on another whammy. The odds are that the Permian extinction entailed a whole lot of whammies, many of which will never be fully understood.

      • The entire planetary ecology was weakened by low atmospheric carbon and very cold weather – just like the present in fact. Warming really doesn’t occur until the Triassic gets underway. Also, while the oceans were probably lower in pH due to the sulphur, they probably were not “acidified” any more than modern oceans are.

      • Duster: which could imply that, through industrial release of trapped CO2, we have aborted a Sixth Mass Extinction.

      • Given the actual paper — the link to which you so helpfully posted — what these folks have that others don’t is high precision radiometric dating of the end-Permian time interval. And they think it shows a period of massive lava eruptions. Followed by a short period of sill intrusion. Followed by another period of massive lava flows. The extinction event is brief and coincides with the start of the sill intrusions.

        From there, it’s pretty much all conjecture, but it doesn’t seem (to me) especially crazy.given the normally accepted standards of geological thought.

        Doesn’t mean it’s “correct”. Even if the data is valid — as it certainly could be — the timing could be coincidence.

      • End-Permian time was probably a lot like hell on Earth for at least 1 million years. It does appear that the mass extinction probably went down in less than 100,000 years. Was this due to the intrusives? Or was it the culmination of a cascading series of catastrophic events? Or was it something yet undiscovered? I doubt there will ever be a definitive answer.

      • It may be difficult to accept that your description of the KT boundary impact is not an impact but the result of exhalative vulcanism without external forces. The type example for this event is the Cretaceous volcanic system in the Whitsundays in FNQ. the four mains types of exhalative volcanics all have very distinct trace metal assemblages. Taking these assemblages and applying them to black shales through out time from the Mesoproterozoic Witswaterand through to the Lewis/San Juan shale shows many repeats all with similar geochemical markers. Even the Middle Devonian shales of the mid West USA show these trace element characteristics. Each of these shales also have a high TOC content that resulted from anoxic conditions on the sea floor. The other interesting description of the role of the black shales in sedimentary basins is the black shales are atypical of the stratigraphic succession that defines the particular basin that they are found in. The black shales that I have seen in the Mid Devonian in the Antrim and Illinois Basins may be described as fine grained crystal ash fall tuffs of rhyolitic composition. They all plot in the same area on the SiO2-K2O-Na2O triangular plot.

      • Akatsukami August 7, 2017 at 5:16 pm

        At best it might have been delayed slightly. We are still way below optimal CO2 levels. The geological evidence suggests that biological and geological capture tends to pull carbon dioxide out of the atmosphere at a greater rate than natural output can supply. The planet has been this cold and this impoverished in carbon once before and that was the end Permian.

    • The coal seam fires, while releasing CO2, would also be releasing solar reflecting soot. The CO2 issue of warming would be completely overwhelmed by the lack of solar irradiance penetrating through that veil. Heck, we are about 2 degrees cooler in NE Oregon due to haze from Pacific Northwest fires from British Columbia to the Southern parts of Oregon. This in spite of CO2 being released from burning greenery.

      • Probably not much soot? Coal seam fires aren’t unheard of. Thing is, they are underground and their progress is limited the ability of Oxygen to work its way down to the coal. Soot and exhaust gases are presumably going to be equally slow to escape.

        They don’t burn fast, but they are very hard to extinguish. They can burn for decades or even longer. Google Centralia, PA. or Mt Wingen, Australia. The latter fire moves along at the rate or about 1 meter per YEAR and is estimated to have been burning for thousands of years.

  9. Looking at Siberia on Google Earth I came across this interesting geological structure (SiberiaRose), sadly I’m told that it is not a meteorite crater.

  10. David, I have a tough time imagining an event like this confined to only sills or even mainly sills. The magma starts off rising vertically along fractures because at depth, the lithostatic pressure makes it impossible to lift the overlying weight to hydraulically force itself along horizontal contacts. By their nature, sills are relatively shallow features such that the overhead burden can be lifted.

    Where a fracture at depth is generated by the intrusion of a magma into older brittle rocks like granites or metamorphic rocks occurs, it proceeds as a fracture up to the surface if it has the energy to do so and of course these rocks don’t have regular horizontal planes to intrude into to form a sill.

    I’m giving a paper on the emplacement of rare metal pegmatites at the AEMA in Reno in December. These are mainly sill type bodies at shallow depth. Pegmatites have been studied mainly my mineralogists and although I love these folk, they have bolloxed up important aspects of how they got where they did. I hope to straighten some of that out.

    • Gary, I assume then, based on your paper’s topic, you know where to find gold. We have lots of it here in NE Oregon. Love those granitic stitching plumes and quarts veins.

      • Pamela, I have explored for base metals, precious metals (found some gold, lode and placer) , rare metals, a host of non metallic metals diamonds… After almost two working lifetimes, I’ve trimmed my area down to rare metals (Li, Ta, Nb, Cs, rare earth metals and the like). It’s a nice niche these days and it gets me all over the world. Those pesky windmills need a lot of rare earth metals, mainly neodymium and disprosium for high intensity magnets.

        The simple thing to think about when prospecting is almost everything comes from below. This means there is a plumbing system connecting mineralization. Fractures in a region tend to have one or two main directions, one following the “bedding” in sedimentary or volcanic layers, and a cross cutting one as a result of regional stresses. Cross fractures are also common (3directions)

        Mineralization often prefers one of these directions or sedimentary /volcanic layerA beginners best chance is to stake extensions on the main trend and keep your eyes pealed for “en echelon” tear fractures in the general trend:
        /
        /
        /

        Smaller veins may occur parallel to the main one or may branch off on a cross cutting fracture.
        /
        /
        /\
        / \

        STAKE ALL AROUND THE EXISTING PROPERTY WITH EXTRA ALONG THE TREND. Then look around the district for similar geology to the staked one.

  11. My guess is that things are much simpler than the “self-anointed smart guys” think.

    Consider the meteor that ended the Cretaceous period.
    You hit a mushy, large billiard ball with the cue ball.

    What happens to the much larger “mushy” ball?
    Why, at the point of impact: splat
    180 degrees, on the other side of the billiard ball?
    …splish, as some of the “guts” pop out.

    But, of course, the Siberian Traps “just happened”.

    • The term is antipodal volcanism; that is, an eruption created by a large meteorite impact roughly on the other side of the planet.

    • It doesn’t take much thought to realize that the 5 mass extinctions spaced out over 600 million years were all caused by meteor/comet impacts. We know they are out there, we know they collide with planets, we know they have collided with our planet, and we know that the impacts can be big enough to significantly disrupt the planet and life on it. Or maybe we should believe, like you said, major geologic events “just happened” on their own with no external influence…just the planetary system periodically breaking down on its own. Of course the only logical conclusion is that too much CO2 attracts meteors and comets.

  12. I am not able to understand the source of the liberated CO2 from contact metamorphism based on the paper [it probably doesn’t need to be made explicit for geologists who already know]. I should note my question isn’t a challenge to the paper, but an effort to understand it. I suspect the clue is in the nature of the layer referenced in the paper as ‘volatile-fertile’ [quoted below] What is this layer? Some form of coal? “Consequently, only a small volume of basin sediments experienced contact metamorphism during stage 1 and thus environmental impacts were likely relatively negligible. Not until the Siberian LIP emplacement style changed at the onset of stage 2 from being dominantly extrusive to intrusive was the “volatile-fertile” Tunguska basin subjected to widespread contact metamorphism, thereby maximizing the likelihood of heat transfer and massive volatile yield.”

    • The “money quote” appears to be:

      Extreme heat from these sills led to ‘contact metamorphism’ (alteration of the composition or structure of a rock by heat or pressure) of carbon-rich rocks.

      The “carbon-rich rocks” were presumably something on the order of limestone, which mainly calcium carbonate. The “contact metamorphism” would have been similar to kilning limestone to quicklime.

      • Thanks, that makes sense. For some reason I was only picturing Limestome>Marble which wouldn’t liberate much CO2. But Limestone>quicklime sure would.

    • Randy,

      Very little, if any, CO2 would be released to the atmosphere by the contact metamorphism of a carbonate rock (Ca,Mg CO3) by a deep-seated diabase dyke or sill. How would CO2 escape from depth to the atmosphere? Most likely, any CO2 produced would react with some other element and precipitate as a carbonate mineral again outside the contact-metamorphic aureole. Contact metamorphism would result in the formation of silicate minerals within the contact-metamorphic aureole.

  13. From what I recall, sea level fluctuated greatly during the Pennsylvanian and Permian period. If so, during the cold periods, CO2 levels may have fallen to the point where life was threatened. I also seem to recall snowball earth events occurring, but that I believe was in the late pre-Cambrian era. Need to look into this further.

  14. Li et al (2009) and others have suggested that the Siberian intrusions burned through particularly sulfidic sediments. The problem is that the oceans are such an enormous Sulfur reservoir, ~a million Gt, that it is hard to imagine even traps scale volcanism causing the marine component of the extinction.

    Another problem is that the “traps” (I have heard this is the Indian word for “steps”) volcanism began somewhat after the marine extinction (Saunders 2009).

    Methinks the keys to the Permian extinction are the extremely low sea level, very unusual during a warm period, and the nasty ocean anoxic event.

    • I thought it was the Dutch word for steps. At least that’s what I vaguely recall from college. Our campus was in the shadow of West Rock in New Haven CT. West Rock, like the Palisades, is a diabase sill in the Newark Supergroup.

      A recent study of the Chicxulub impact also points to sulfides and sulfate aerosols. The meteor impacted thick gypsum-rich evaporite deposits.

    • Trap is the Swedish word for “stair”. The term originally applied to basalt layers on top of limestone hills in western Sweden.
      And yes, an extreme anoxic event that liberated large amounts of highly toxic H2S into the atmosphere could have been the killer mechanism.

  15. Every single mass extinction has a insane levels of sea level change at the time. The only answer would be lots of cooling that creates hundreds of feet of sea level decrease over a very short amount of time, then swinging back, then cold again. Episodic intense cold pulses is the only one that makes sense to me. To me massive releases of SO2 when combining with H20 creating sulphuric acid would be the double whammy of acid rain and reduced temperatures as water vapour (by far the most important GHG) is removed from the air. SO2 is likely to blame for the decreased temperatures in the 60’s and 70’s and part of the 80’s (coal plants adding large amounts of SO2) and the large bounce back in the 90’s (with the addition of SO2 scrubbers) which some climate scientists thought would continue on forever even accelerating.

    • Was there sea level change at the Cretaceous-Paleogene boundary? Sea level had been falling during the last age of the Cretaceous, the Maastrichtian, but it was hot all during the Late Cretaceous and in the following Paleocene and Eocene epochs of the Paleogene Period.

  16. Not even worth a second thought. Any time research veers off into the pseudoscience of CO2 hysteria and throws around things like “deadly levels of greenhouse gases into the atmosphere.” it’s plain crap. Unfortunately even some geologists are being indoctrinated by the cult. They are a load shy of having a brick.

  17. Has the precise geologic and subsequent sequence of events suggested by this latest GHG wheeze ever actually been observed or found in any other location on a smaller scale since the alleged hot bedpan Permian episode proposed by this paper. If not we can consign it as appropriately belonging to the steaming bedpan.
    I am always surprised at the vehemence shown when the KT boundary impact is disputed as being a volcanic or ocean gas event first and foremost. Since an impact of such severity would have knock on effects which we cannot fully be certain about, I see no reason to doubt volcanism and ocean and atmospheric chemistry would have gone haywire for some possibly extended period. In any case there appears to be a second impact site in southern Russia dating to 65 million years. Seems unlikely the two impacts would not be related (though of course may not be).

    • As above, Shiva crater and Deccan Traps. I believe there is evidence for 5 or 6 impacts around 65mya.

    • It may be difficult to accept that your description of the KT boundary impact is not an impact but the result of exhalative vulcanism without external forces. The type example for this event is the Cretaceous volcanic system in the Whitsundays in FNQ. the four mains types of exhalative volcanics all have very distinct trace metal assemblages. Taking these assemblages and applying them to black shales through out time from the Mesoproterozoic Witswaterand through to the Lewis/San Juan shale shows many repeats all with similar geochemical markers. Even the Middle Devonian shales of the mid West USA show these trace element characteristics. Each of these shales also have a high TOC content that resulted from anoxic conditions on the sea floor. The other interesting description of the role of the black shales in sedimentary basins is the black shales are atypical of the stratigraphic succession that defines the particular basin that they are found in. The black shales that I have seen in the Mid Devonian in the Antrim and Illinois Basins may be described as fine grained crystal ash fall tuffs of rhyolitic composition. They all plot in the same area on the SiO2-K2O-Na2O triangular plot.

  18. Teacher: “Johnny, what’s the longest river in the world?”
    Johnny: “The Nile, I guess.”
    Teacher: “Johnny, you can’t go through life just guessing!!”
    Johnny: “Oh yes I can: I’m going to be a geologist!”

  19. Geologists, like engineers, are excellent and we should respect them. It is only when political considerations about carbon dioxide and evil humans being the cause of everything bad that has ever happened intrude that the trouble starts.

  20. When it comes to mass extinction events one question that is seldom addressed are the species whose fossil records show they were relatively unaffected by the event.

    I first became aware of this when invited to do geochemical analysis of the excellent K-T boundary record in New Zealand by a micropaleontologist studying the sequence. The extinction sequence is selective. My fading memories recall my reading around the Permian event and finding that was undoubtedly selective too.

    Whatever the explanation for a mass-extinction it has to be of a nature that allows, as in the case of the Permian, 30-odd% of land species to survive. The difficult question is not what died out or how many but what were unaffected.

    • Happily for us, the ancestors of mammals survived the Permian mass extinction event (MEE). Our synapsid relatives had dominated the land in the Permian, but among the few survivors were the protomammals.

      The formerly minor diapsid amniotes however gradually came to dominate the Mesozoic, especially after the end Triassic MEE.

      However, in the immediate aftermath of the Mother of All MEEs, a genus of mammalian relative was nearly ubiquitous on Pangaea, the Early Triassic “pig lizard” Lystrosaurus:

      • This hypothesis has recently been challenged, but it was thought that dicynodonts survived because they were adapted for burrowing, adapted to low oxygen condirions, despite being kin to mammals.

        Similarly, the Triassic rise of archosaurs, ie croc relatives, pterosaurs and dinosaurs, was due to their four-chambered hearts and erect gaits, improving oxygen circulation. Birds and their saurischian dinosaur relatives (theropods and sauropods) also have air sacs in their bones.

  21. In the spirit of showing geological diversity of thought – and questioning assumptions about melts and high temperatures, I refer you to a new book by my colleague John Elliston AO, geologist extraordinaire.
    http://www.connorcourt.com/catalog1/index.php?main_page=product_info&products_id=402&zenid=mqq7no8mugeu5ia28pefi9k8o5#.WYkl_dIjGpo

    This is a life work that raises the importance of gels, small particle/high surface areas, colloids, problems of granite genesis and many other implications.
    It is one of those rare books that puts a spectrum of new thought into an fairly established field.
    Geoff.

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